stopped using the word currently frequently

CHANGELOG.md

@@ -1,4 +1,10 @@
+## 1.4
 
+* Added window creation backends. GLava automatically uses the appropriate backend, currently `"glx"` and `"glfw"` are available. The GLX window creation code nicely supports transparent windows so that users do not need to use GLFW 3.3 for native transparency, which remains unstable and unreleased.
+* Added a `--backend` (or `-b`) flag that can be used to manually select window creation backends.
+* Fixed alpha blending with `"native"` transparency. GLava now correctly uses premultiplied alpha to provide alpha blending with other X windows, where a compositor is available.
+* Fixed a segmentation fault that occurs with uncommon window managers, see #19
+* Fixed various other issues with alpha blending in shader code.
 
 ## 1.3
 

Makefile

@@ -4,7 +4,7 @@ obj = $(src:.c=.o)
 # Build type parameter
 
 ifeq ($(BUILD),debug)
-    CFLAGS_BUILD = -O1 -ggdb -Wall -fsanitize=address -fno-omit-frame-pointer -fno-optimize-sibling-calls
+    CFLAGS_BUILD = -O0 -ggdb -Wall -fsanitize=address -fno-omit-frame-pointer -fno-optimize-sibling-calls
     GLAD_GEN = c-debug
     ASAN = -lasan
 else
@@ -38,12 +38,22 @@ ifeq ($(INSTALL),unix)
     endif
 endif
 
+ifndef DISABLE_GLFW
+    CFLAGS_GLFW = -DGLAVA_GLFW
+    LDFLAGS_GLFW = -lglfw
+endif
+
+ifndef DISABLE_GLX
+    CFLAGS_GLX = -DGLAVA_GLX
+    LDFLAGS_GLX = -lGLX -lXrender
+endif
+
 ifeq ($(INSTALL),osx)
     CFLAGS_INSTALL = -DGLAVA_OSX
     SHADER_DIR = Library/glava
 endif
 
-LDFLAGS = $(ASAN) -lpulse -lpulse-simple -pthread -lglfw -ldl -lm -lX11 -lXext
+LDFLAGS = $(ASAN) -lpulse -lpulse-simple -pthread $(LDFLAGS_GLFW) -ldl -lm -lX11 -lXext $(LDFLAGS_GLX)
 
 PYTHON = python
 
@@ -51,7 +61,7 @@ GLAD_INSTALL_DIR = glad
 GLAD_SRCFILE = ./glad/src/glad.c
 GLAD_ARGS = --generator=$(GLAD_GEN) --extensions=GL_EXT_framebuffer_multisample,GL_EXT_texture_filter_anisotropic
 CFLAGS_COMMON = -I glad/include
-CFLAGS_USE = $(CFLAGS_COMMON) $(CFLAGS_BUILD) $(CFLAGS_INSTALL) $(CFLAGS)
+CFLAGS_USE = $(CFLAGS_COMMON) $(CFLAGS_GLX) $(CFLAGS_GLFW) $(CFLAGS_BUILD) $(CFLAGS_INSTALL) $(CFLAGS)
 
 all: glava
 

README.md

@@ -19,7 +19,7 @@ You can pass `BUILD=debug` to the makefile for debug builds of both glad and gla
 
 - X11
 - PulseAudio
-- GLFW 3.1+
+- GLFW 3.1+ (optional, disable with `DISABLE_GLFW=1`)
 - Linux or BSD
 
 **Additional compile time requirements:**
@@ -27,8 +27,9 @@ You can pass `BUILD=debug` to the makefile for debug builds of both glad and gla
 - glad (included as a submodule)
 - python (required to generate bindings with glad)
 - GCC (this program uses GNU C features)
+- GLX headers (optional, disable direct GLX support with `DISABLE_GLX=1`), usually the development packages for `libgl` include this on your distro
 
-**Ubuntu/Debian users:** the following command ensures you have all the needed packages and headers to compile and run GLava:
+**Ubuntu/Debian users:** the following command ensures you have all the needed packages and headers to compile GLava:
 ```bash
 sudo apt-get install libpulse libpulse-dev libglfw3 libglfw3-dev libxext6 libxext6-dev python make gcc
 ```
@@ -43,28 +44,25 @@ To embed GLava in your desktop (for EWMH compliant window managers), use `#reque
 
 \* On an XDG compliant Linux or BSD system. OSX will use `/Library/glava` and `~/Library/Preferences/glava` instead.
 
-**Note for `#request setopacity`:** While most users will prefer the faster `xroot` transparency, GLFW 3.3 (unreleased) is needed in order to support the `native` transparency option (older versions still work). Arch users can install `glfw-x11-git` from the AUR and recompile GLava for this feature.
-
 ## Desktop window compatibility
 
 GLava aims to be compatible with _most_ EWMH compliant window managers. Below is a list of common window managers and issues specific to them for trying to get GLava to behave as a desktop window or widget:
 
 | WM | ! | Details
 | :---: | --- | --- |
-| GNOME (on X11) | ![-](https://placehold.it/15/118932/000000?text=+) | No notable issues
+| Mutter (GNOME, Budgie) | ![-](https://placehold.it/15/118932/000000?text=+) | `"native"` (default) opacity should be used
 | Openbox (LXDE or standalone) | ![-](https://placehold.it/15/118932/000000?text=+) | [Some tweaks may be required](https://www.reddit.com/r/unixporn/comments/7vcgi4/oc_after_receiving_positive_feedback_here_i/dtrkvja/)
 | Xfwm (XFCE) | ![-](https://placehold.it/15/118932/000000?text=+) | Untested, but should work without issues
 | Fluxbox | ![-](https://placehold.it/15/118932/000000?text=+) | Untested, but should work without issues
 | iceWM | ![-](https://placehold.it/15/118932/000000?text=+) | No notable issues
-| AwesomeWM | ![-](https://placehold.it/15/f09c00/000000?text=+) | Requires the WM to be restarted (`Super + Ctl + R`) in order for new desktop windows to behave correctly, can still be focused, may require other changes to config depending on layout
-| Budgie Desktop | ![-](https://placehold.it/15/f09c00/000000?text=+) | `"xroot"` transparency breaks with Budgie's wallpaper window
+| Herbstluftwm | ![-](https://placehold.it/15/118932/000000?text=+) | `hc rule windowtype~'_NET_WM_WINDOW_TYPE_DESKTOP' manage=off` can be used to unmanage desktop windows
+| AwesomeWM | ![-](https://placehold.it/15/f09c00/000000?text=+) | Can still be focused, may require other changes to config depending on layout
 | kwin (KDE) | ![-](https://placehold.it/15/f09c00/000000?text=+) | [Issues with workspaces and stacking](https://github.com/wacossusca34/glava/issues/4), needs further testing
 | i3 (and i3-gaps) | ![-](https://placehold.it/15/f03c15/000000?text=+) | [i3 does not respect the `"desktop"` window type](https://github.com/wacossusca34/glava/issues/6)
 | EXWM | ![-](https://placehold.it/15/f03c15/000000?text=+) | EXWM does not have a desktop, and forces window decorations
 | Unity | ![-](https://placehold.it/15/1589F0/000000?text=+) | Needs testing
 | Enlightenment | ![-](https://placehold.it/15/1589F0/000000?text=+) | Needs testing
 | Bspwm | ![-](https://placehold.it/15/1589F0/000000?text=+) | Needs testing
-| Herbstluftwm | ![-](https://placehold.it/15/1589F0/000000?text=+) | Needs testing
 | xmonad | ![-](https://placehold.it/15/1589F0/000000?text=+) | Needs testing
 | Any non EWMH-compliant WM | ![-](https://placehold.it/15/f03c15/000000?text=+) | Window types and hints will not work if the window manager does not support the EWMH standards.
 

glava.c

@@ -18,7 +18,7 @@
 #include "render.h"
 #include "xwin.h"
 
-#define GLAVA_VERSION "1.3"
+#define GLAVA_VERSION "1.4"
 #ifdef GLAD_DEBUG
 #define GLAVA_RELEASE_TYPE_PREFIX "debug, "
 #else
@@ -167,18 +167,22 @@ static const char* help_str =
     "-C, --copy-config       creates copies and symbolic links in the user configuration\n"
     "                          directory for glava, copying any files in the root directory\n"
     "                          of the installed shader directory, and linking any modules.\n"
+    "-b, --backend           specifies a window creation backend to use. By default, the most\n"
+    "                          appropriate backend will be used for the underlying windowing\n"
+    "                          system.\n"
     "-V, --version           print application version and exit\n"
     "\n"
     GLAVA_VERSION_STRING "\n"
     " -- Copyright (C) 2017 Levi Webb\n";
 
-static const char* opt_str = "hvVe:Cm:";
+static const char* opt_str = "hvVe:Cm:b:";
 static struct option p_opts[] = {
     {"help",        no_argument,       0, 'h'},
     {"verbose",     no_argument,       0, 'v'},
     {"entry",       required_argument, 0, 'e'},
     {"force-mod",   required_argument, 0, 'm'},
     {"copy-config", no_argument,       0, 'C'},
+    {"backend",     required_argument, 0, 'b'},
     {"version",     no_argument,       0, 'V'},
     {0,             0,                 0,  0 }
 };
@@ -190,6 +194,7 @@ int main(int argc, char** argv) {
     const char* user_path    = SHADER_USER_PATH;
     const char* entry        = "rc.glsl";
     const char* force        = NULL;
+    const char* backend      = NULL;
     const char* system_shader_paths[] = { user_path, install_path, NULL };
     bool verbose = false;
     bool copy_mode = false;
@@ -201,6 +206,7 @@ int main(int argc, char** argv) {
         case 'C': copy_mode = true;   break;
         case 'e': entry     = optarg; break;
         case 'm': force     = optarg; break;
+        case 'b': backend   = optarg; break;
         case '?': exit(EXIT_FAILURE); break;
         case 'V':
             puts(GLAVA_VERSION_STRING);
@@ -219,7 +225,7 @@ int main(int argc, char** argv) {
         exit(EXIT_SUCCESS);
     }
 
-    renderer* r = rd_new(system_shader_paths, entry, force);
+    renderer* r = rd_new(system_shader_paths, entry, force, backend);
 
     float b0[r->bufsize_request], b1[r->bufsize_request];
     size_t t;
@@ -274,7 +280,7 @@ int main(int argc, char** argv) {
         pthread_mutex_unlock(&audio.mutex);
         
         /* Only render if needed (ie. stop rendering when fullscreen windows are focused) */
-        if (xwin_should_render()) {
+        if (xwin_should_render(r)) {
             rd_update(r, lb, rb, r->bufsize_request, modified);
         } else {
             /* Sleep for 50ms and then attempt to render again */

glfw_wcb.c

@@ -0,0 +1,138 @@
+
+/* GLFW window and OpenGL context creation. */
+
+#ifdef GLAVA_GLFW
+
+#define GLAVA_RDX11
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+#include <errno.h>
+
+#include <X11/Xlib.h>
+
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+
+#include "render.h"
+#include "xwin.h"
+
+#define GLFW_EXPOSE_NATIVE_X11
+
+/* Hack to make GLFW 3.1 headers work with GLava. We don't use the context APIs from GLFW, but
+   the old headers require one of them to be selected for exposure in glfw3native.h. */
+#if GLFW_VERSION_MAJOR == 3 && GLFW_VERSION_MINOR <= 1
+#define GLFW_EXPOSE_NATIVE_GLX
+#endif
+#include <GLFW/glfw3native.h>
+
+/* Fixes for old GLFW versions */
+#ifndef GLFW_TRUE
+#define GLFW_TRUE GL_TRUE
+#endif
+#ifndef GLFW_FALSE
+#define GLFW_FALSE GL_FALSE
+#endif
+
+#define DECL_WINDOW_HINT(F, H) \
+    static void F(bool var) { glfwWindowHint(H, var); }
+#define DECL_WINDOW_HINT_STUB(F) \
+    static void F(bool _) { fprintf(stderr, "Warning: " #F " not implemented for GLFW backend\n"); }
+
+static void init(void) {
+    if (!glfwInit()) {
+        fprintf(stderr, "glfwInit(): failed\n");
+        abort();
+    }
+
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+    glfwWindowHint(GLFW_FLOATING, GLFW_FALSE);
+    glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);
+}
+
+
+DECL_WINDOW_HINT(set_floating,  GLFW_FLOATING);
+DECL_WINDOW_HINT(set_decorated, GLFW_DECORATED);
+DECL_WINDOW_HINT(set_focused,   GLFW_FOCUSED);
+#ifdef GLFW_MAXIMIZED
+DECL_WINDOW_HINT(set_maximized, GLFW_MAXIMIZED);
+#else
+DECL_WINDOW_HINT_STUB(set_maximized);
+#endif
+
+extern struct gl_wcb wcb_glfw;
+
+static void* create_and_bind(const char* name, const char* class,
+                             const char* type, const char** states,
+                             size_t states_sz,
+                             int d, int h,
+                             int x, int y,
+                             int version_major, int version_minor) {
+
+    GLFWwindow* w;
+    
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, version_major);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, version_minor);
+    
+    if (!(w = glfwCreateWindow(d, h, class, NULL, NULL))) {
+        fprintf(stderr, "glfwCreateWindow(): failed\n");
+        glfwTerminate();
+        return NULL;
+    }
+    
+    if (type)
+        xwin_settype(&wcb_glfw, w, type);
+
+    for (size_t t = 0; t < states_sz; ++t)
+        xwin_addstate(&wcb_glfw, w, states[t]);
+    
+    glfwSetWindowPos(w, x, y);
+    glfwMakeContextCurrent(w);
+    
+    gladLoadGLLoader((GLADloadproc) glfwGetProcAddress);
+    
+    return w;
+}
+
+static void set_transparent(bool transparent) {
+    #ifdef GLFW_TRANSPARENT_FRAMEBUFFER
+    glfwWindowHint(GLFW_TRANSPARENT_FRAMEBUFFER, transparent ? GLFW_TRUE : GLFW_FALSE);
+    #elif GLFW_TRANSPARENT
+    glfwWindowHint(GLFW_TRANSPARENT, transparent ? GLFW_TRUE : GLFW_FALSE);
+    #else
+    if (transparent)
+        fprintf(stderr, "Warning: the linked version of GLFW3 does not have transparency support"
+               " (GLFW_TRANSPARENT[_FRAMEBUFFER])!\n");
+    #endif
+}
+
+static void set_geometry(GLFWwindow* w, int x, int y, int d, int h) {
+    glfwSetWindowPos(w, x, y);
+    glfwSetWindowSize(w, d, h);
+}
+
+static void set_visible(GLFWwindow* w, bool visible) {
+    if (visible) glfwShowWindow(w);
+    else         glfwHideWindow(w);
+}
+
+static bool swap_buffers(GLFWwindow* w) {
+    glfwSwapBuffers(w);
+    glfwPollEvents();
+}
+
+static Display* get_x11_display(void)                          { return glfwGetX11Display();      }
+static Window   get_x11_window (GLFWwindow* w)                 { return glfwGetX11Window(w);      }
+static bool     should_close   (GLFWwindow* w)                 { return glfwWindowShouldClose(w); }
+static void     get_fbsize     (GLFWwindow* w, int* d, int* h) { glfwGetFramebufferSize(w, d, h); }
+static void     get_pos        (GLFWwindow* w, int* x, int* y) { glfwGetWindowPos(w, x, y);       }
+static double   get_time       (GLFWwindow* w)                 { return glfwGetTime();            }
+static void     set_time       (GLFWwindow* w, double time)    { glfwSetTime(time);               }
+static void     set_swap       (int i)                         { glfwSwapInterval(i); }
+
+WCB_ATTACH("glfw", wcb_glfw);
+
+#endif /* GLAVA_GLFW */

glx_wcb.c

@@ -0,0 +1,278 @@
+
+/* Xlib window creation and GLX context creation backend */
+
+#ifdef GLAVA_GLX
+
+#define GLAVA_RDX11
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+#include <errno.h>
+#include <math.h>
+#include <time.h>
+
+#include <X11/Xlib.h>
+#include <X11/extensions/Xrender.h>
+#include <X11/Xatom.h>
+
+#include <glad/glad.h>
+#include <GL/glx.h>
+
+#include "render.h"
+#include "xwin.h"
+
+#define GLX_CONTEXT_MAJOR_VERSION_ARB       0x2091
+#define GLX_CONTEXT_MINOR_VERSION_ARB       0x2092
+typedef GLXContext (*glXCreateContextAttribsARBProc)(Display*, GLXFBConfig, GLXContext, Bool, const int*);
+typedef void       (*glXSwapIntervalEXTProc)        (Display*, GLXDrawable, int);
+
+extern struct gl_wcb wcb_glx;
+
+static Display* display;
+
+static int swap;
+
+static bool floating, decorated, focused, maximized, transparent;
+
+struct glxwin {
+    Window w;
+    GLXContext context;
+    double time;
+    bool should_close;
+};
+
+static void init(void) {
+    display = XOpenDisplay(NULL);
+    if (!display) {
+        fprintf(stderr, "XOpenDisplay(): could not establish connection to X11 server\n");
+        abort();
+    }
+    floating    = false;
+    decorated   = true;
+    focused     = false;
+    maximized   = false;
+    transparent = false;
+}
+
+static void apply_decorations(Window w) {
+    if (!decorated) {
+        struct {
+            unsigned long flags, functions, decorations;
+            long input_mode;
+            unsigned long status;
+        } hints;
+
+        hints.flags       = 2;
+        hints.decorations = 0;
+        
+        Atom motif = XInternAtom(display, "_MOTIF_WM_HINTS", false);
+
+        XChangeProperty(display, w, motif, motif, 32, PropModeReplace,
+                        (unsigned char*) &hints, sizeof(hints) / sizeof(long));
+    }
+}
+
+static void* create_and_bind(const char* name, const char* class,
+                             const char* type, const char** states,
+                             size_t states_sz,
+                             int d, int h,
+                             int x, int y,
+                             int version_major, int version_minor) {
+    struct glxwin* w = malloc(sizeof(struct glxwin));
+    w->time         = 0.0D;
+    w->should_close = false;
+
+    XVisualInfo* vi;
+    XSetWindowAttributes attr;
+    GLXFBConfig* fbc;
+    int fb_sz, best = -1, samp = -1;
+
+    static int gl_attrs[] = {
+        GLX_X_RENDERABLE,  True,
+        GLX_DRAWABLE_TYPE, GLX_WINDOW_BIT,
+        GLX_RENDER_TYPE,   GLX_RGBA_BIT,
+        GLX_X_VISUAL_TYPE, GLX_TRUE_COLOR,
+        GLX_DOUBLEBUFFER,  True,
+        GLX_RED_SIZE,      8,
+        GLX_GREEN_SIZE,    8,
+        GLX_BLUE_SIZE,     8,
+        GLX_ALPHA_SIZE,    8,
+        None
+    };
+    
+    int context_attrs[] = {
+        GLX_CONTEXT_MAJOR_VERSION_ARB, version_major,
+        GLX_CONTEXT_MINOR_VERSION_ARB, version_minor,
+        // GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB,
+        None
+    };
+    
+    fbc = glXChooseFBConfig(display, DefaultScreen(display), gl_attrs, &fb_sz);
+    if (!fbc) {
+        fprintf(stderr, "glXChooseFBConfig(): failed\n" );
+        abort();
+    }
+    
+    for (int t = 0; t < fb_sz; ++t) {
+        XVisualInfo* xvi = glXGetVisualFromFBConfig(display, fbc[t]);
+        if (xvi) {
+            int samp_buf, samples;
+            glXGetFBConfigAttrib(display, fbc[t], GLX_SAMPLE_BUFFERS, &samp_buf);
+            glXGetFBConfigAttrib(display, fbc[t], GLX_SAMPLES,        &samples );
+            XRenderPictFormat* fmt = XRenderFindVisualFormat(display, xvi->visual);
+            
+            if (!fmt || (transparent ? fmt->direct.alphaMask == 0 : fmt->direct.alphaMask != 0))
+                continue;
+            
+            if (best < 0 || samp_buf && samples > samp) {
+                best = t;
+                samp = samples;
+            }
+            XFree(xvi);
+        }
+    }
+
+    if (best == -1) {
+        fprintf(stderr, "Could not find suitable format for FBConfig\n");
+        abort();
+    }
+
+    GLXFBConfig config = fbc[best];
+    XFree(fbc);
+    
+    vi = glXGetVisualFromFBConfig(display, config);
+    
+    attr.colormap          = XCreateColormap(display, DefaultRootWindow(display), vi->visual, AllocNone);
+    attr.event_mask        = ExposureMask | KeyPressMask | StructureNotifyMask;
+    attr.background_pixmap = None;
+    attr.border_pixel      = 0;
+    
+    if (!(w->w = XCreateWindow(display, DefaultRootWindow(display),
+                               x, y, d, h, 0,
+                               vi->depth, InputOutput, vi->visual,
+                               CWColormap | CWEventMask | CWBackPixmap | CWBorderPixel,
+                               &attr))) {
+        fprintf(stderr, "XCreateWindow(): failed\n");
+        abort();
+    }
+    
+    if (type)
+        xwin_settype(&wcb_glx, w, type);
+
+    for (size_t t = 0; t < states_sz; ++t)
+        xwin_addstate(&wcb_glx, w, states[t]);
+
+    if (floating) xwin_addstate(&wcb_glx, w, "above");
+    if (maximized) {
+        xwin_addstate(&wcb_glx, w, "maximized_horz");
+        xwin_addstate(&wcb_glx, w, "maximized_vert");
+    }
+
+    XSetClassHint(display, w->w, &((XClassHint) { .res_name = (char*) class, .res_class = (char*) class }));
+
+    apply_decorations(w->w);
+
+    XFree(vi);
+    
+    XStoreName(display, w->w, name);
+
+    Atom dwin = XInternAtom(display, "WM_DELETE_WINDOW", false);
+    XSetWMProtocols(display, w->w, &dwin, 1);
+
+    glXCreateContextAttribsARBProc glXCreateContextAttribsARB = NULL;
+    glXSwapIntervalEXTProc glXSwapIntervalEXT = NULL;
+    glXCreateContextAttribsARB = (glXCreateContextAttribsARBProc)
+        glXGetProcAddressARB((const GLubyte*) "glXCreateContextAttribsARB");
+    glXSwapIntervalEXT = (glXSwapIntervalEXTProc)
+        glXGetProcAddressARB((const GLubyte*) "glXSwapIntervalEXT");
+
+    if (!glXCreateContextAttribsARB) {
+        fprintf(stderr, "glXGetProcAddressARB(\"glXCreateContextAttribsARB\"): failed\n");
+        abort();
+    }
+
+    if (!(w->context = glXCreateContextAttribsARB(display, config, 0, True, context_attrs))) {
+        fprintf(stderr, "glXCreateContextAttribsARB(): failed\n");
+        abort();
+    }
+
+    XSync(display, False);
+    
+    glXMakeCurrent(display, w->w, w->context);
+    gladLoadGL();
+
+    GLXDrawable drawable = glXGetCurrentDrawable();
+    
+    if (glXSwapIntervalEXT) glXSwapIntervalEXT(display, drawable, swap);
+
+    return w;
+}
+
+static void set_swap       (int  _swap)        { swap        = _swap;        }
+static void set_floating   (bool _floating)    { floating    = _floating;    }
+static void set_decorated  (bool _decorated)   { decorated   = _decorated;   }
+static void set_focused    (bool _focused)     { focused     = _focused;     }
+static void set_maximized  (bool _maximized)   { maximized   = _maximized;   }
+static void set_transparent(bool _transparent) { transparent = _transparent; }
+
+static void set_geometry(struct glxwin* w, int x, int y, int d, int h) {
+    XMoveResizeWindow(display, w->w, x, y, (unsigned int) d, (unsigned int) h);
+}
+
+static void set_visible(struct glxwin* w, bool visible) {
+    if (visible) XMapWindow(display, w->w);
+    else XUnmapWindow(display, w->w);
+}
+
+static bool should_close(struct glxwin* w) {
+    return w->should_close;
+}
+
+static void swap_buffers(struct glxwin* w) {
+    glXSwapBuffers(display, w->w);
+    
+    while (XPending(display) > 0) {
+        XEvent ev;
+        XNextEvent(display, &ev);
+        switch (ev.type) {
+        case ClientMessage:
+            if (ev.xclient.message_type  == XInternAtom(display, "WM_PROTOCOLS", 1)
+                && ev.xclient.data.l[0]  == XInternAtom(display, "WM_DELETE_WINDOW", 1)) {
+                w->should_close = true;
+            }
+        default: break;
+        }
+    }
+}
+
+static void get_fbsize(struct glxwin* w, int* d, int* h) {
+    XWindowAttributes a;
+    XGetWindowAttributes(display, w->w, &a);
+    *d = a.width;
+    *h = a.height;
+}
+
+static void get_pos(struct glxwin* w, int* x, int* y) {
+    XWindowAttributes a;
+    Window _ignored;
+    XTranslateCoordinates(display, w->w, DefaultRootWindow(display), 0, 0, x, y, &_ignored);
+}
+
+static double get_timert(void) {
+    struct timespec tv;
+    if (clock_gettime(CLOCK_REALTIME, &tv)) {
+        fprintf(stderr, "clock_gettime(CLOCK_REALTIME, ...): %s\n", strerror(errno));
+    }
+    return (double) tv.tv_sec + ((double) tv.tv_nsec / 1000000000.0D);
+}
+
+static double   get_time       (struct glxwin* w)              { return get_timert() - w->time; }
+static void     set_time       (struct glxwin* w, double time) { w->time = get_timert() - time; }
+static Display* get_x11_display(struct glxwin* w)              { return display; }
+static Window   get_x11_window (struct glxwin* w)              { return w->w;    }
+
+WCB_ATTACH("glx", wcb_glx);
+
+#endif /* GLAVA_GLX */

render.c

@@ -14,15 +14,6 @@
 #include <unistd.h>
 
 #include <glad/glad.h>
-#include <GLFW/glfw3.h>
-
-/* Fixes for old GLFW versions */
-#ifndef GLFW_TRUE
-#define GLFW_TRUE GL_TRUE
-#endif
-#ifndef GLFW_FALSE
-#define GLFW_FALSE GL_FALSE
-#endif
 
 #include "render.h"
 #include "xwin.h"
@@ -44,6 +35,17 @@
 #define VERTEX_SHADER_SRC \
     "layout(location = 0) in vec3 pos; void main() { gl_Position = vec4(pos.x, pos.y, 0.0F, 1.0F); }"
 
+struct gl_wcb* wcbs[2] = {};
+static size_t wcbs_idx = 0;
+
+static inline void register_wcb(struct gl_wcb* wcb) { wcbs[wcbs_idx++] = wcb; }
+
+#define DECL_WCB(N)                             \
+    do {                                        \
+        extern struct gl_wcb N;                 \
+        register_wcb(&N);                       \
+    } while (0)
+
 /* GLSL bind source */
  
 struct gl_bind_src {
@@ -83,7 +85,7 @@ struct gl_bind {
 
 struct gl_sfbo {
     GLuint fbo, tex, shader;
-    bool valid;
+    bool valid, nativeonly;
     const char* name;
     struct gl_bind* binds;
     size_t binds_sz;
@@ -100,13 +102,14 @@ struct gl_data {
     struct overlay_data overlay;
     GLuint audio_tex_r, audio_tex_l, bg_tex, sm_prog;
     size_t stages_sz, bufscale, avg_frames;
-    GLFWwindow* w;
+    void* w;
+    struct gl_wcb* wcb;
     int lww, lwh, lwx, lwy; /* last window dimensions */
     int rate; /* framerate */
     double tcounter;
     int fcounter, ucounter, kcounter;
     bool print_fps, avg_window, interpolate, force_geometry, copy_desktop,
-        smooth_pass, use_alpha;
+        smooth_pass, premultiply_alpha;
     void** t_data;
     float gravity_step, target_spu, fr, ur, smooth_distance, smooth_ratio,
         smooth_factor, fft_scale, fft_cutoff;
@@ -117,6 +120,8 @@ struct gl_data {
     int geometry[4];
 };
 
+
+
 /* load shader file */
 static GLuint shaderload(const char*             rpath,
                          GLenum                  type,
@@ -160,7 +165,8 @@ static GLuint shaderload(const char*             rpath,
         "#define UNIFORM_LIMIT %d\n"
         "#define PRE_SMOOTHED_AUDIO %d\n"
         "#define SMOOTH_FACTOR %.6f\n"
-        "#define USE_ALPHA %d\n";
+        "#define USE_ALPHA %d\n"
+        "#define PREMULTIPLY_ALPHA %d\n";
     
     struct glsl_ext ext = {
         .source     = raw ? NULL : map,
@@ -175,11 +181,11 @@ static GLuint shaderload(const char*             rpath,
     /* If this is raw input, skip processing */
     if (!raw) ext_process(&ext, rpath);
     
-    size_t blen = strlen(header_fmt) + 42;
+    size_t blen = strlen(header_fmt) + 64;
     GLchar* buf = malloc((blen * sizeof(GLchar*)) + ext.p_len);
     int written = snprintf(buf, blen, header_fmt, (int) shader_version, (int) max_uniforms,
                            gl->smooth_pass ? 1 : 0, (double) gl->smooth_factor,
-                           gl->use_alpha ? 1 : 0);
+                           1, gl->premultiply_alpha ? 1 : 0);
     if (written < 0) {
         fprintf(stderr, "snprintf() encoding error while prepending header to shader '%s'\n", path);
         return 0;
@@ -676,7 +682,8 @@ static struct gl_bind_src* lookup_bind_src(const char* str) {
     return NULL;
 }
 
-struct renderer* rd_new(const char** paths, const char* entry, const char* force_mod) {
+struct renderer* rd_new(const char** paths, const char* entry,
+                        const char* force_mod, const char* force_backend) {
     
     renderer* r = malloc(sizeof(struct renderer));
     *r = (struct renderer) {
@@ -690,35 +697,79 @@ struct renderer* rd_new(const char** paths, const char* entry, const char* force
     
     struct gl_data* gl = r->gl;
     *gl = (struct gl_data) {
-        .w               = NULL,
-        .stages          = NULL,
-        .rate            = 0,
-        .tcounter        = 0.0D,
-        .fcounter        = 0,
-        .ucounter        = 0,
-        .kcounter        = 0,
-        .fr              = 1.0F,
-        .ur              = 1.0F,
-        .print_fps       = true,
-        .bufscale        = 1,
-        .avg_frames      = 6,
-        .avg_window      = true,
-        .gravity_step    = 4.2,
-        .interpolate     = true,
-        .force_geometry  = false,
-        .smooth_factor   = 0.025,
-        .smooth_distance = 0.01,
-        .smooth_ratio    = 4,
-        .bg_tex          = 0,
-        .sm_prog         = 0,
-        .copy_desktop    = true,
-        .use_alpha       = true,
-        .smooth_pass     = true,
-        .fft_scale       = 10.2F,
-        .fft_cutoff      = 0.3F,
-        .geometry        = { 0, 0, 500, 400 },
-        .clear_color     = { 0.0F, 0.0F, 0.0F, 0.0F }
+        .w                 = NULL,
+        .wcb               = NULL,
+        .stages            = NULL,
+        .rate              = 0,
+        .tcounter          = 0.0D,
+        .fcounter          = 0,
+        .ucounter          = 0,
+        .kcounter          = 0,
+        .fr                = 1.0F,
+        .ur                = 1.0F,
+        .print_fps         = true,
+        .bufscale          = 1,
+        .avg_frames        = 6,
+        .avg_window        = true,
+        .gravity_step      = 4.2,
+        .interpolate       = true,
+        .force_geometry    = false,
+        .smooth_factor     = 0.025,
+        .smooth_distance   = 0.01,
+        .smooth_ratio      = 4,
+        .bg_tex            = 0,
+        .sm_prog           = 0,
+        .copy_desktop      = true,
+        .premultiply_alpha = true,
+        .smooth_pass       = true,
+        .fft_scale         = 10.2F,
+        .fft_cutoff        = 0.3F,
+        .geometry          = { 0, 0, 500, 400 },
+        .clear_color       = { 0.0F, 0.0F, 0.0F, 0.0F }
     };
+
+    bool forced = force_backend != NULL;
+    const char* backend = force_backend;
+
+    /* Window creation backend interfaces */
+    #ifdef GLAVA_GLFW
+    DECL_WCB(wcb_glfw);
+    if (!forced) backend = "glfw";
+    #endif
+
+    #ifdef GLAVA_GLX
+    DECL_WCB(wcb_glx);
+    if (!forced && !getenv("WAYLAND_DISPLAY") && getenv("DISPLAY")) {
+        backend = "glx";
+    }
+    #endif
+
+    if (!backend) {
+        fprintf(stderr, "No backend available for the active windowing system\n");
+        if (wcbs_idx == 0) {
+            fprintf(stderr, "None have been compiled into this build.\n");
+        } else {
+            fprintf(stderr, "Available backends:\n");
+            for (size_t t = 0; t < wcbs_idx; ++t) {
+                fprintf(stderr, "\t\"%s\"\n", wcbs[t]->name);
+            }
+        }
+        exit(EXIT_FAILURE);
+    }
+
+    printf("Using backend: '%s'\n", backend);
+
+    for (size_t t = 0; t < wcbs_idx; ++t) {
+        if (wcbs[t]->name && !strcmp(wcbs[t]->name, backend)) {
+            gl->wcb = wcbs[t];
+            break;
+        }
+    };
+
+    if (!gl->wcb) {
+        fprintf(stderr, "Invalid window creation backend selected: '%s'\n", gl->wcb);
+        abort();
+    }
     
     #ifdef GLAD_DEBUG
     printf("Assigning debug callback\n");
@@ -729,15 +780,11 @@ struct renderer* rd_new(const char** paths, const char* entry, const char* force
     }
     #endif
     
-    if (!glfwInit())
-        abort();
+    gl->wcb->init();
 
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-    glfwWindowHint(GLFW_FLOATING, GLFW_FALSE);
-    glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);
-
-    int shader_version = 330;
+    int shader_version        = 330,
+        context_version_major = 3,
+        context_version_minor = 3;
     const char* module = force_mod;
     char* xwintype = NULL, * wintitle = "GLava";
     char** xwinstates = malloc(1);
@@ -746,15 +793,9 @@ struct renderer* rd_new(const char** paths, const char* entry, const char* force
     struct gl_sfbo* current = NULL;
     size_t t_count = 0;
 
-    #define WINDOW_HINT(request, attr)                                  \
-        { .name = request, .fmt = "b",                                  \
-                .handler = RHANDLER(name, args, { glfwWindowHint(attr, *(bool*) args[0]); }) }
-    
-    #define STUB(request, f)                                            \
-        { .name = request, .fmt = f,                                    \
-                .handler = RHANDLER(name, args, {                       \
-                        fprintf(stderr, "warning: '%s' request is not implemented for this build\n", \
-                                request); }) }
+    #define WINDOW_HINT(request)                                        \
+        { .name = "set" #request, .fmt = "b",                           \
+                .handler = RHANDLER(name, args, { gl->wcb->set_##request(*(bool*) args[0]); }) }
     
     struct request_handler handlers[] = {
         {
@@ -763,19 +804,9 @@ struct renderer* rd_new(const char** paths, const char* entry, const char* force
 
                     bool native_opacity = !strcmp("native", (char*) args[0]);
                     
-                    gl->use_alpha = true;
-                    
-                    #ifdef GLFW_TRANSPARENT_FRAMEBUFFER
-                    glfwWindowHint(GLFW_TRANSPARENT_FRAMEBUFFER, native_opacity ? GLFW_TRUE : GLFW_FALSE);
-                    if (native_opacity) gl->use_alpha = false;
-                    #elif GLFW_TRANSPARENT
-                    glfwWindowHint(GLFW_TRANSPARENT, native_opacity ? GLFW_TRUE : GLFW_FALSE);
-                    if (native_opacity) gl->use_alpha = false;
-                    #else
-                    if (native_opacity)
-                        printf("WARNING: the linked version of GLFW3 does not have transparency support"
-                               " (GLFW_TRANSPARENT[_FRAMEBUFFER])!\n"); 
-                    #endif
+                    gl->premultiply_alpha = native_opacity;
+
+                    gl->wcb->set_transparent(native_opacity);
 
                     if (!strcmp("xroot", (char*) args[0]))
                         gl->copy_desktop = true;
@@ -823,19 +854,26 @@ struct renderer* rd_new(const char** paths, const char* entry, const char* force
                     }
                 })
         },
-        WINDOW_HINT("setfloating",  GLFW_FLOATING),
-        WINDOW_HINT("setdecorated", GLFW_DECORATED),
-        WINDOW_HINT("setfocused",   GLFW_FOCUSED),
-        #ifdef GLFW_MAXIMIZED
-        WINDOW_HINT("setmaximized", GLFW_MAXIMIZED),
-        #else
-        STUB("setmaximized", "b"),
-        #endif
+        {
+            .name = "nativeonly", .fmt = "b",
+            .handler = RHANDLER(name, args, {
+                    if (current)
+                        current->nativeonly = *(bool*) args[0];
+                    else {
+                        fprintf(stderr, "`nativeonly` request needs module context\n");
+                        exit(EXIT_FAILURE);
+                    }
+                })
+        },
+        WINDOW_HINT(floating),
+        WINDOW_HINT(decorated),
+        WINDOW_HINT(focused),
+        WINDOW_HINT(maximized),
         {
             .name = "setversion", .fmt = "ii",
             .handler = RHANDLER(name, args, {
-                    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, *(int*) args[0]);
-                    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, *(int*) args[1]);
+                    context_version_major = *(int*) args[0];
+                    context_version_minor = *(int*) args[1];
                 })
         },
         {
@@ -865,7 +903,7 @@ struct renderer* rd_new(const char** paths, const char* entry, const char* force
         {   .name = "setshaderversion", .fmt = "i",
             .handler = RHANDLER(name, args, { shader_version = *(int*) args[0]; })           },
         {   .name = "setswap", .fmt = "i",
-            .handler = RHANDLER(name, args, { glfwSwapInterval(*(int*) args[0]); })          },
+            .handler = RHANDLER(name, args, { gl->wcb->set_swap(*(int*) args[0]); })         },
         {   .name = "setframerate", .fmt = "i",
             .handler = RHANDLER(name, args, { gl->rate = *(int*) args[0]; })                 },
         {   .name = "setprintframes", .fmt = "b",
@@ -1035,26 +1073,16 @@ struct renderer* rd_new(const char** paths, const char* entry, const char* force
         exit(EXIT_FAILURE);
     }
     
-    if (!(gl->w = glfwCreateWindow(500, 400, wintitle, NULL, NULL))) {
-        glfwTerminate();
+    if (!(gl->w = gl->wcb->create_and_bind(wintitle, "GLava", xwintype,
+                                           (const char**) xwinstates, xwinstates_sz,
+                                           gl->geometry[2], gl->geometry[3],
+                                           gl->geometry[0], gl->geometry[1],
+                                           context_version_major, context_version_minor))) {
         abort();
     }
     
-    if (xwintype) {
-        xwin_settype(r, xwintype);
-        free(xwintype);
-    }
-
-    for (size_t t = 0; t < xwinstates_sz; ++t) {
-        xwin_addstate(r, xwinstates[t]);
-    }
-    free(xwinstates);
-    
-    glfwSetWindowPos(gl->w, gl->geometry[0], gl->geometry[1]);
-    glfwSetWindowSize(gl->w, gl->geometry[2], gl->geometry[3]);
-
-    glfwMakeContextCurrent(gl->w);
-    gladLoadGLLoader((GLADloadproc) glfwGetProcAddress);
+    if (xwintype)   free(xwintype);
+    if (xwinstates) free(xwinstates);
 
     glDisable(GL_DEPTH_TEST);
     glDisable(GL_DEPTH_CLAMP);
@@ -1063,8 +1091,10 @@ struct renderer* rd_new(const char** paths, const char* entry, const char* force
     glDisable(GL_MULTISAMPLE);
     glDisable(GL_LINE_SMOOTH);
 
-    glEnable(GL_BLEND);
-    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+    if (!gl->premultiply_alpha) {
+        glEnable(GL_BLEND);
+        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+    }
     
     size_t m_len = strlen(module);
     size_t bsz = d_len + m_len + 2;
@@ -1125,11 +1155,12 @@ struct renderer* rd_new(const char** paths, const char* entry, const char* force
                         
                             struct gl_sfbo* s = &stages[idx - 1];
                             *s = (struct gl_sfbo) {
-                                .name     = strdup(d->d_name),
-                                .shader   = 0,
-                                .valid    = false,
-                                .binds    = malloc(1),
-                                .binds_sz = 0
+                                .name       = strdup(d->d_name),
+                                .shader     = 0,
+                                .valid      = false,
+                                .nativeonly = false,
+                                .binds      = malloc(1),
+                                .binds_sz   = 0
                             };
 
                             current = s;
@@ -1144,7 +1175,7 @@ struct renderer* rd_new(const char** paths, const char* entry, const char* force
                                as it can rendered directly */
                             if (idx != count) {
                                 int w, h;
-                                glfwGetFramebufferSize(gl->w, &w, &h);
+                                gl->wcb->get_fbsize(gl->w, &w, &h);
                                 setup_sfbo(&stages[idx - 1], w, h);
                             }
 
@@ -1167,6 +1198,23 @@ struct renderer* rd_new(const char** paths, const char* entry, const char* force
             } while (found);
         }
     }
+    
+    gl->stages = stages;
+    gl->stages_sz = count;
+    
+    {
+        struct gl_sfbo* final = NULL;
+        if (!gl->premultiply_alpha) {
+            for (size_t t = 0; t < gl->stages_sz; ++t) {
+                if (!gl->stages[t].nativeonly) {
+                    final = &gl->stages[t];
+                }
+            }
+        }
+        /* Invalidate framebuffer and use direct rendering if it was instantiated 
+           due to a following `nativeonly` shader pass. */
+        if (final) final->valid = false;
+    }
 
     /* Compile smooth pass shader */
     
@@ -1177,15 +1225,11 @@ struct renderer* rd_new(const char** paths, const char* entry, const char* force
         char util[usz]; /* module pack path to use */
         snprintf(util, usz, "%s/%s", data, util_folder);
         loading_smooth_pass = true;
-        if (!(gl->sm_prog = shaderbuild(gl, util, data, handlers, shader_version, "smooth_pass.frag"))) {
+        if (!(gl->sm_prog = shaderbuild(gl, util, data, handlers, shader_version, "smooth_pass.frag")))
             abort();
-        }
         loading_smooth_pass = false;
     }
     
-    gl->stages = stages;
-    gl->stages_sz = count;
-    
     /* target seconds per update */
     gl->target_spu = (float) (r->samplesize_request / 4) / (float) r->rate_request;
     
@@ -1217,7 +1261,7 @@ struct renderer* rd_new(const char** paths, const char* entry, const char* force
     
     glClearColor(gl->clear_color.r, gl->clear_color.g, gl->clear_color.b, gl->clear_color.a);
 
-    glfwShowWindow(gl->w);
+    gl->wcb->set_visible(gl->w, true);
     
     return r;
 }
@@ -1225,14 +1269,14 @@ struct renderer* rd_new(const char** paths, const char* entry, const char* force
 void rd_time(struct renderer* r) {
     struct gl_data* gl = r->gl;
     
-    glfwSetTime(0.0D); /* reset time for measuring this frame */
+    gl->wcb->set_time(gl->w, 0.0D); /* reset time for measuring this frame */
 }
 
 void rd_update(struct renderer* r, float* lb, float* rb, size_t bsz, bool modified) {
     struct gl_data* gl = r->gl;
     size_t t, a, fbsz = bsz * sizeof(float);
     
-    r->alive = !glfwWindowShouldClose(gl->w);
+    r->alive = !gl->wcb->should_close(gl->w);
     if (!r->alive)
         return;
 
@@ -1287,8 +1331,8 @@ void rd_update(struct renderer* r, float* lb, float* rb, size_t bsz, bool modifi
         }
     }
     int ww, wh, wx, wy;
-    glfwGetFramebufferSize(gl->w, &ww, &wh);
-    glfwGetWindowPos(gl->w, &wx, &wy);
+    gl->wcb->get_fbsize(gl->w, &ww, &wh);
+    gl->wcb->get_pos(gl->w, &wx, &wy);
     
     /* Resize screen textures if needed */
     if (ww != gl->lww || wh != gl->lwh) {
@@ -1321,6 +1365,9 @@ void rd_update(struct renderer* r, float* lb, float* rb, size_t bsz, bool modifi
         
         /* Current shader program */
         struct gl_sfbo* current = &gl->stages[t];
+
+        if (current->nativeonly && !gl->premultiply_alpha)
+            continue;
         
         /* Bind framebuffer if this is not the final pass */
         if (current->valid)
@@ -1339,8 +1386,8 @@ void rd_update(struct renderer* r, float* lb, float* rb, size_t bsz, bool modifi
                 "out vec4 fragment;"                                                                 "\n"
                 "in vec4 gl_FragCoord;"                                                              "\n"
                 "void main() {"                                                                      "\n"
-                "    fragment = texture(tex, vec2(gl_FragCoord.x / screen.x, "                       "\n"
-                "                       (screen.y - gl_FragCoord.y) / screen.y));"                   "\n"
+                "    fragment = texelFetch(tex, ivec2(gl_FragCoord.x, "                              "\n"
+                "                       screen.y - gl_FragCoord.y), 0);"                             "\n"
                 "    fragment.a = 1.0F;"                                                             "\n"
                 "}"                                                                                  "\n";
             if (!setup) {
@@ -1361,9 +1408,9 @@ void rd_update(struct renderer* r, float* lb, float* rb, size_t bsz, bool modifi
             /* We need to disable blending, we might read in bogus alpha values due
                to how we obtain the background texture (format is four byte `rgb_`, 
                where the last value is skipped) */
-            glDisable(GL_BLEND);
+            if (!gl->premultiply_alpha) glDisable(GL_BLEND);
             drawoverlay(&gl->overlay);
-            glEnable(GL_BLEND);
+            if (!gl->premultiply_alpha) glEnable(GL_BLEND);
             glUseProgram(0);
         }
         
@@ -1441,7 +1488,8 @@ void rd_update(struct renderer* r, float* lb, float* rb, size_t bsz, bool modifi
     
                         /* setup and bind framebuffer to texture */
                         glBindFramebuffer(GL_FRAMEBUFFER, sm->fbo);
-                        glFramebufferTexture1D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_1D, sm->tex, 0);
+                        glFramebufferTexture1D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,\
+                                               GL_TEXTURE_1D, sm->tex, 0);
                         
                         switch (glCheckFramebufferStatus(GL_FRAMEBUFFER)) {
                         case GL_FRAMEBUFFER_COMPLETE: break;
@@ -1462,11 +1510,11 @@ void rd_update(struct renderer* r, float* lb, float* rb, size_t bsz, bool modifi
                     glUniform1i(sm_uw, sz);  /* target texture width */
                     glUniform1i(sm_usz, sz); /* source texture width */
                     glUniform1i(sm_utex, offset);
-                    glDisable(GL_BLEND);
+                    if (!gl->premultiply_alpha) glDisable(GL_BLEND);
                     glViewport(0, 0, sz, 1);
                     drawoverlay(&gl->overlay);
                     glViewport(0, 0, ww, wh);
-                    glEnable(GL_BLEND);
+                    if (!gl->premultiply_alpha) glEnable(GL_BLEND);
 
                     /* Return state */
                     glUseProgram(current->shader);
@@ -1527,10 +1575,9 @@ void rd_update(struct renderer* r, float* lb, float* rb, size_t bsz, bool modifi
     }
 
     /* Swap buffers, handle events, etc. (vsync is potentially included here, too) */
-    glfwSwapBuffers(gl->w);
-    glfwPollEvents();
+    gl->wcb->swap_buffers(gl->w);
 
-    double duration = glfwGetTime(); /* frame execution time */
+    double duration = gl->wcb->get_time(gl->w); /* frame execution time */
 
     /* Handling sleeping (to meet target framerate) */
     if (gl->rate > 0) {
@@ -1566,8 +1613,9 @@ void rd_update(struct renderer* r, float* lb, float* rb, size_t bsz, bool modifi
         
         /* Refresh window position and size if we are forcing it */
         if (gl->force_geometry) {
-            glfwSetWindowPos(gl->w, gl->geometry[0], gl->geometry[1]);
-            glfwSetWindowSize(gl->w, gl->geometry[2], gl->geometry[3]);
+            gl->wcb->set_geometry(gl->w,
+                                  gl->geometry[0], gl->geometry[1],
+                                  gl->geometry[2], gl->geometry[3]);
         }
     }
 
@@ -1575,11 +1623,11 @@ void rd_update(struct renderer* r, float* lb, float* rb, size_t bsz, bool modifi
     gl->interpolate = old_interpolate;
 }
 
-void* rd_get_impl_window(struct renderer* r) { return r->gl->w; }
+void*          rd_get_impl_window (struct renderer* r)  { return r->gl->w;   }
+struct gl_wcb* rd_get_wcb         (struct renderer* r)  { return r->gl->wcb; }
 
 void rd_destroy(struct renderer* r) {
     /* TODO: delete everything else, not really needed though (as the application exits after here) */
-    glfwTerminate();
     free(r->gl);
     free(r);
 }

render.h

@@ -1,4 +1,7 @@
 
+#ifndef RENDER_H
+#define RENDER_H
+
 struct gl_data;
 
 typedef struct renderer {
@@ -8,8 +11,72 @@ typedef struct renderer {
     struct gl_data* gl;
 } renderer;
 
-struct renderer* rd_new(const char** paths, const char* entry, const char* force_mod);
-void             rd_update(struct renderer*, float* lb, float* rb, size_t bsz, bool modified);
-void             rd_destroy(struct renderer*);
-void             rd_time(struct renderer*);
+struct renderer* rd_new            (const char** paths, const char* entry,
+                                    const char* force_mod, const char* force_backend);
+void             rd_update         (struct renderer*, float* lb, float* rb,
+                                    size_t bsz, bool modified);
+void             rd_destroy        (struct renderer*);
+void             rd_time           (struct renderer*);
 void*            rd_get_impl_window(struct renderer*);
+struct gl_wcb*   rd_get_wcb        (struct renderer*);
+
+/* gl_wcb - OpenGL Window Creation Backend interface */
+struct gl_wcb {
+    const char* name;
+    void     (*init)           (void);
+    void*    (*create_and_bind)(const char* name, const char* class,
+                                const char* type, const char** states,
+                                size_t states_sz,
+                                int w, int h,
+                                int x, int y,
+                                int version_major, int version_minor);
+    bool     (*should_close)   (void* ptr);
+    bool     (*swap_buffers)   (void* ptr);
+    void     (*get_pos)        (void* ptr, int* x, int* y);
+    void     (*get_fbsize)     (void* ptr, int* w, int* h);
+    void     (*set_geometry)   (void* ptr, int x, int y, int w, int h);
+    void     (*set_swap)       (int interval);
+    void     (*set_floating)   (bool floating);
+    void     (*set_decorated)  (bool decorated);
+    void     (*set_focused)    (bool focused);
+    void     (*set_maximized)  (bool maximized);
+    void     (*set_transparent)(bool transparent);
+    double   (*get_time)       (void* ptr);
+    void     (*set_time)       (void* ptr, double time);
+    void     (*set_visible)    (void* ptr, bool visible);
+    #ifdef GLAVA_RDX11
+    Display* (*get_x11_display)(void);
+    Window   (*get_x11_window) (void* ptr);
+    #else /* define placeholders to ensure equal struct size */
+    void* _X11_DISPLAY_PLACEHOLDER;
+    void* _X11_WINDOW_PLACEHOLDER;
+    #endif
+};
+
+#define WCB_FUNC(F)                                 \
+    .F = (typeof(((struct gl_wcb*) NULL)->F)) &F
+
+#define WCB_ATTACH(B, N)                        \
+    struct gl_wcb N = {                         \
+        .name = B,                              \
+        WCB_FUNC(init),                         \
+        WCB_FUNC(create_and_bind),              \
+        WCB_FUNC(should_close),                 \
+        WCB_FUNC(swap_buffers),                 \
+        WCB_FUNC(set_swap),                     \
+        WCB_FUNC(get_pos),                      \
+        WCB_FUNC(get_fbsize),                   \
+        WCB_FUNC(set_geometry),                 \
+        WCB_FUNC(set_floating),                 \
+        WCB_FUNC(set_decorated),                \
+        WCB_FUNC(set_focused),                  \
+        WCB_FUNC(set_maximized),                \
+        WCB_FUNC(set_transparent),              \
+        WCB_FUNC(set_time),                     \
+        WCB_FUNC(get_time),                     \
+        WCB_FUNC(set_visible),                  \
+        WCB_FUNC(get_x11_display),              \
+        WCB_FUNC(get_x11_window)                \
+    }
+
+#endif /* RENDER_H */

shaders/circle.glsl

@@ -1,7 +1,7 @@
 /* center radius (pixels) */
 #define C_RADIUS 128
 /* center line thickness (pixels) */
-#define C_LINE 2
+#define C_LINE 1.5
 /* outline color */
 #define OUTLINE #333333
 /* Amplify magnitude of the results each bar displays */

shaders/circle/3.frag

@@ -0,0 +1 @@
+#include ":util/premultiply.frag"

shaders/radial/1.frag

@@ -29,10 +29,10 @@ out vec4 fragment;
 #define PI 3.14159265359
 
 void main() {
-
+    
     #if USE_ALPHA > 0
-    #define APPLY_FRAG(f, c) f = vec4(f.rgb * f.a + c.rgb * (1 - f.a), max(c.a, f.a))
-    fragment.a = 0;
+    #define APPLY_FRAG(f, c) f = vec4(f.rgb * f.a + c.rgb * (1 - clamp(f.a, 0, 1)), max(c.a, f.a))
+    fragment = #00000000;
     #else
     #define APPLY_FRAG(f, c) f = c
     #endif
@@ -46,9 +46,9 @@ void main() {
     float theta = atan(dy, dx); /* fragment angle with the center of the screen as the origin */
     float d = sqrt((dx * dx) + (dy * dy)); /* distance */
     if (d > C_RADIUS - (float(C_LINE) / 2.0F) && d < C_RADIUS + (float(C_LINE) / 2.0F)) {
-        fragment = OUTLINE;
+        APPLY_FRAG(fragment, OUTLINE);
         #if USE_ALPHA > 0
-        fragment.a *= ((float(C_LINE) / 2.0F) - abs(d - C_RADIUS)) * C_ALIAS_FACTOR;
+        fragment.a *= clamp(((C_LINE / 2) - abs(C_RADIUS - d)) * C_ALIAS_FACTOR, 0, 1);
         #else
         return; /* return immediately if there is no alpha blending available */
         #endif

shaders/radial/2.frag

@@ -0,0 +1 @@
+#include ":util/premultiply.frag"

shaders/rc.glsl

@@ -15,23 +15,22 @@
    See documentation for more details. */
 #request mod bars
 
-/* GLFW window hints */
+/* Window hints */
 #request setfloating  false
-#request setdecorated false
+#request setdecorated true
 #request setfocused   false
 #request setmaximized false
 
-/* Force GLFW window geometry (locking the window in place),
-   useful for some pesky WMs that try to reposition the window
-   when embedding in the desktop. */
+/* Force window geometry (locking the window in place), useful
+   for some pesky WMs that try to reposition the window when
+   embedding in the desktop. */
 #request setforcegeometry false
 
 /* Set window background opacity mode. Possible values are:
    
-   "native" - True transparency provided by the compositor.
-              Requires GLFW 3.3+ and an active compositor. Can
-              reduce performance on some systems, and will not
-              blend with the visualizer's alpha layer.
+   "native" - True transparency provided by the compositor. Can
+              reduce performance on some systems, depending on
+              the compositor used.
    
    "xroot"  - Maintain a copy of the root window's pixmap
               (usually the desktop background) to provide a
@@ -40,22 +39,22 @@
               Has very little performance impact.
     
    "none"   - Disable window opacity completely. */
-#request setopacity "xroot"
+#request setopacity "native"
 
 /* OpenGL context and GLSL shader versions, do not change unless
    you *absolutely* know what you are doing. */
 #request setversion 3 3
 #request setshaderversion 330
 
-/* GLFW window title */
+/* Window title */
 #request settitle "GLava"
 
-/* GLFW window geometry (x, y, width, height) */
-#request setgeometry 0 0 400 600
+/* Window geometry (x, y, width, height) */
+#request setgeometry 0 0 800 600
 
 /* Window background color (RGB format).
-   Only works with `setopacity "none"` */
-#request setbg 3C3C3C
+   Does not work with `setopacity "xroot"` */
+#request setbg 00000000
 
 /* (X11 only) EWMH Window type. Possible values are:
    
@@ -96,7 +95,7 @@
    default output device. */
 #request setsource "auto"
 
-/* GLFW buffer swap interval (vsync), set to '0' to prevent
+/* Buffer swap interval (vsync), set to '0' to prevent
    waiting for refresh, '1' (or more) to wait for the specified
    amount of frames. */
 #request setswap 1

shaders/util/premultiply.frag

@@ -0,0 +1,15 @@
+
+#request nativeonly true
+
+#request uniform "prev" tex
+uniform sampler2D tex;
+
+out vec4 fragment;
+in vec4 gl_FragCoord;
+
+void main() {
+    fragment = texelFetch(tex, ivec2(gl_FragCoord.x, gl_FragCoord.y), 0);
+    #if PREMULTIPLY_ALPHA > 0
+    fragment.rgb *= fragment.a;
+    #endif
+}

xwin.c

@@ -12,27 +12,50 @@
 #include <sys/shm.h>
 
 #include <X11/Xlib.h>
+#include <X11/Xutil.h>
 #include <X11/Xatom.h>
+#include <X11/extensions/Xcomposite.h>
 #include <X11/extensions/XShm.h>
 
-#define GLFW_EXPOSE_NATIVE_X11
-
 #include <glad/glad.h>
-#include <GLFW/glfw3.h>
-
-/* Hack to make GLFW 3.1 headers work with GLava. We don't use the context APIs from GLFW, but
-   the old headers require one of them to be selected for exposure in glfw3native.h. */
-#if GLFW_VERSION_MAJOR == 3 && GLFW_VERSION_MINOR <= 1
-#define GLFW_EXPOSE_NATIVE_GLX
-#endif
-#include <GLFW/glfw3native.h>
 
+#define GLAVA_RDX11
 #include "render.h"
 #include "xwin.h"
 
-bool xwin_should_render(void) {
+static Window find_desktop(struct renderer* r) {
+    static Window desktop;
+    static bool searched = false;
+    if (!searched) {
+        Display* d = rd_get_wcb(r)->get_x11_display();
+        desktop = DefaultRootWindow(d);
+        Window _ignored, * children;
+        unsigned int nret;
+        XQueryTree(d, desktop, &_ignored, &_ignored, &children, &nret);
+        if (children) {
+            for (unsigned int t = 0; t < nret; ++t) {
+                char* name;
+                XFetchName(d, children[t], &name);
+                if (name) {
+                    /* Mutter-based window managers */
+                    if (!strcmp(name, "mutter guard window")) {
+                        printf("Using mutter guard window instead of root window\n");
+                        // desktop = children[t];
+                        t = nret; /* break after */
+                    }
+                    XFree(name);
+                }
+            }
+            XFree(children);
+        }
+        searched = true;
+    }
+    return desktop;
+}
+
+bool xwin_should_render(struct renderer* rd) {
     bool ret = true, should_close = false;
-    Display* d = glfwGetX11Display();
+    Display* d = rd_get_wcb(rd)->get_x11_display();
     if (!d) {
         d = XOpenDisplay(0);
         should_close = true;
@@ -50,11 +73,14 @@ bool xwin_should_render(void) {
     
     XSetErrorHandler(handler); /* dummy error handler */
           
-    if (Success != XGetWindowProperty(d, RootWindow(d, 0), prop, 0, 1, false, AnyPropertyType,
+    if (Success != XGetWindowProperty(d, DefaultRootWindow(d), prop, 0, 1, false, AnyPropertyType,
                                      &actual_type, &actual_format, &nitems, &bytes_after, &data)) {
         goto close; /* if an error occurs here, the WM probably isn't EWMH compliant */
     }
 
+    if (!nitems)
+        goto close;
+    
     Window active = ((Window*) data)[0];
 
     prop = XInternAtom(d, "_NET_WM_STATE", true);
@@ -76,9 +102,10 @@ bool xwin_should_render(void) {
 
 /* Set window types defined by the EWMH standard, possible values:
    -> "desktop", "dock", "toolbar", "menu", "utility", "splash", "dialog", "normal" */
-static void xwin_changeatom(struct renderer* rd, const char* type, const char* atom, const char* fmt, int mode) {
-    Window w = glfwGetX11Window((GLFWwindow*) rd_get_impl_window(rd));
-    Display* d = glfwGetX11Display();
+static void xwin_changeatom(struct gl_wcb* wcb, void* impl, const char* type,
+                            const char* atom, const char* fmt, int mode) {
+    Window w = wcb->get_x11_window(impl);
+    Display* d = wcb->get_x11_display();
     Atom wtype = XInternAtom(d, atom, false);
     size_t len = strlen(type), t;
     char formatted[len + 1];
@@ -95,16 +122,16 @@ static void xwin_changeatom(struct renderer* rd, const char* type, const char* a
     XChangeProperty(d, w, wtype, XA_ATOM, 32, mode, (unsigned char*) &desk, 1);
 }
 
-void xwin_settype(struct renderer* rd, const char* type) {
-    xwin_changeatom(rd, type, "_NET_WM_WINDOW_TYPE", "_NET_WM_WINDOW_TYPE_%s", PropModeReplace); 
+void xwin_settype(struct gl_wcb* wcb, void* impl, const char* type) {
+    xwin_changeatom(wcb, impl, type, "_NET_WM_WINDOW_TYPE", "_NET_WM_WINDOW_TYPE_%s", PropModeReplace); 
 }
 
-void xwin_addstate(struct renderer* rd, const char* state) {
-    xwin_changeatom(rd, state, "_NET_WM_STATE", "_NET_WM_STATE_%s", PropModeAppend); 
+void xwin_addstate(struct gl_wcb* wcb, void* impl, const char* state) {
+    xwin_changeatom(wcb, impl, state, "_NET_WM_STATE", "_NET_WM_STATE_%s", PropModeAppend); 
 }
 
-static Pixmap get_pixmap(Display* d, Window w) {
-    Pixmap p;
+static Drawable get_drawable(Display* d, Window w) {
+    Drawable p;
     Atom act_type;
     int act_format;
     unsigned long nitems, bytes_after;
@@ -112,14 +139,14 @@ static Pixmap get_pixmap(Display* d, Window w) {
     Atom id;
 
     id = XInternAtom(d, "_XROOTPMAP_ID", False);
-
+    
     if (XGetWindowProperty(d, w, id, 0, 1, False, XA_PIXMAP,
                            &act_type, &act_format, &nitems, &bytes_after,
-                           &data) == Success) {
-        if (data) {
-            p = *((Pixmap *) data);
-            XFree(data);
-        }
+                           &data) == Success && data) {
+        p = *((Pixmap *) data);
+        XFree(data);
+    } else {
+        p = w;
     }
 
     return p;
@@ -133,112 +160,123 @@ unsigned int xwin_copyglbg(struct renderer* rd, unsigned int tex) {
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
     
-    GLFWwindow* gwin = (GLFWwindow*) rd_get_impl_window(rd);
+    bool use_shm = true;
+    
     int x, y, w, h;
-    glfwGetFramebufferSize(gwin, &w, &h);
-    glfwGetWindowPos(gwin, &x, &y);
+    rd_get_wcb(rd)->get_fbsize(rd_get_impl_window(rd), &w, &h);
+    rd_get_wcb(rd)->get_pos(rd_get_impl_window(rd), &x, &y);
     XColor c;
-    Display* d = glfwGetX11Display();
-    Pixmap p = get_pixmap(d, RootWindow(d, DefaultScreen(d)));
+    Display* d = rd_get_wcb(rd)->get_x11_display();
+    Drawable src = get_drawable(d, find_desktop(rd));
 
-    /* Obtain section of root pixmap using XShm */
+    /* Obtain section of root pixmap */
     
     XShmSegmentInfo shminfo;
     Visual* visual = DefaultVisual(d, DefaultScreen(d));
     XVisualInfo match = { .visualid = XVisualIDFromVisual(visual) };
     int nret;
     XVisualInfo* info = XGetVisualInfo(d, VisualIDMask, &match, &nret);
-    XImage* image = XShmCreateImage(d, visual, info->depth, ZPixmap, NULL,
-                                    &shminfo, (unsigned int) w, (unsigned int) h);
-    if ((shminfo.shmid = shmget(IPC_PRIVATE, image->bytes_per_line * image->height, IPC_CREAT | 0777)) == -1) {
-        fprintf(stderr, "shmget() failed: %s\n", strerror(errno));
-        exit(EXIT_FAILURE);
+    XImage* image;
+    if (use_shm) {
+        image = XShmCreateImage(d, visual, info->depth, ZPixmap, NULL,
+                                &shminfo, (unsigned int) w, (unsigned int) h);
+        if ((shminfo.shmid = shmget(IPC_PRIVATE, image->bytes_per_line * image->height,
+                                    IPC_CREAT | 0777)) == -1) {
+            fprintf(stderr, "shmget() failed: %s\n", strerror(errno));
+            exit(EXIT_FAILURE);
+        }
+        shminfo.shmaddr = image->data = shmat(shminfo.shmid, 0, 0);
+        shminfo.readOnly = false;
+        XShmAttach(d, &shminfo);
+        XShmGetImage(d, src, image, x, y, AllPlanes);
+    } else {
+        image = XGetImage(d, src, x, y, (unsigned int) w, (unsigned int) h,
+                  ZPixmap, AllPlanes);
     }
-    shminfo.shmaddr = image->data = shmat(shminfo.shmid, 0, 0);
-    shminfo.readOnly = false;
-    XShmAttach(d, &shminfo);
-    XShmGetImage(d, p, image, x, y, AllPlanes);
 
     /* Try to convert pixel bit depth to OpenGL storage format. The following formats\
        will need intermediate conversion before OpenGL can accept the data:
        
        - 8-bit pixel formats (retro displays, low-bandwidth virtual displays)
        - 36-bit pixel formats (rare deep color displays) */
-    
-    bool invalid = false, aligned = false;
-    GLenum type;
-    switch (image->bits_per_pixel) {
-    case 16:
-        switch (image->depth) {
-        case 12: type = GL_UNSIGNED_SHORT_4_4_4_4; break; /* 12-bit (rare)    */
-        case 15: type = GL_UNSIGNED_SHORT_5_5_5_1; break; /* 15-bit, hi-color */
-        case 16:                                          /* 16-bit, hi-color */
-            type    = GL_UNSIGNED_SHORT_5_6_5;
-            aligned = true;
-            break;
-        }
-        break;
-    case 32:
-        switch (image->depth) {
-        case 24: type = GL_UNSIGNED_BYTE;           break; /* 24-bit, true color */
-        case 30: type = GL_UNSIGNED_INT_10_10_10_2; break; /* 30-bit, deep color */
-        }
-        break;
-    case 64: 
-        if (image->depth == 48) /* 48-bit deep color */
-            type = GL_UNSIGNED_SHORT;
-        else goto invalid;
-        break;
-        /* >64-bit formats */
-    case 128:
-        if (image->depth == 96)
-            type = GL_UNSIGNED_INT;
-        else goto invalid;
-        break;
-    default:
-    invalid: invalid = true;
-    }
-    
-    uint8_t* buf;
-    if (invalid) {
-        abort();
-        /* Manual reformat (slow) */
-        buf = malloc(4 * w * h);
-        int xi, yi;
-        Colormap map = DefaultColormap(d, DefaultScreen(d));
-        for (yi = 0; yi < h; ++yi) {
-            for (xi = 0; xi < w; ++xi) {
-                c.pixel = XGetPixel(image, xi, yi);
-                XQueryColor(d, map, &c);
-                size_t base = (xi + (yi * w)) * 4;
-                buf[base + 0] = c.red   / 256;
-                buf[base + 1] = c.green / 256;
-                buf[base + 2] = c.blue  / 256;
-                buf[base + 3] = 255;
+
+    if (image) {
+        bool invalid = false, aligned = false;
+        GLenum type;
+        switch (image->bits_per_pixel) {
+        case 16:
+            switch (image->depth) {
+            case 12: type = GL_UNSIGNED_SHORT_4_4_4_4; break; /* 12-bit (rare)    */
+            case 15: type = GL_UNSIGNED_SHORT_5_5_5_1; break; /* 15-bit, hi-color */
+            case 16:                                          /* 16-bit, hi-color */
+                type    = GL_UNSIGNED_SHORT_5_6_5;
+                aligned = true;
+                break;
             }
+            break;
+        case 32:
+            switch (image->depth) {
+            case 24: type = GL_UNSIGNED_BYTE;           break; /* 24-bit, true color */
+            case 30: type = GL_UNSIGNED_INT_10_10_10_2; break; /* 30-bit, deep color */
+            }
+            break;
+        case 64: 
+            if (image->depth == 48) /* 48-bit deep color */
+                type = GL_UNSIGNED_SHORT;
+            else goto invalid;
+            break;
+            /* >64-bit formats */
+        case 128:
+            if (image->depth == 96)
+                type = GL_UNSIGNED_INT;
+            else goto invalid;
+            break;
+        default:
+        invalid: invalid = true;
         }
     
-        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, buf);
-        free(buf);
-    } else {
-        /* Use image data directly. The alpha value is garbage/unassigned data, but
-           we need to read it because X11 keeps pixel data aligned */
-        buf = (uint8_t*) image->data;
-        /* Data could be 2, 4, or 8 byte aligned, the RGBA format and type (depth)
-           already ensures reads will be properly aligned across scanlines */
-        glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
-        GLenum format = image->bitmap_bit_order == LSBFirst ?
-            (!aligned ? GL_BGRA : GL_BGR) :
-            (!aligned ? GL_RGBA : GL_RGB);
-        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, format, type, buf);
-        glPixelStorei(GL_UNPACK_ALIGNMENT, 4); /* restore default */
+        uint8_t* buf;
+        if (invalid) {
+            abort();
+            /* Manual reformat (slow) */
+            buf = malloc(4 * w * h);
+            int xi, yi;
+            Colormap map = DefaultColormap(d, DefaultScreen(d));
+            for (yi = 0; yi < h; ++yi) {
+                for (xi = 0; xi < w; ++xi) {
+                    c.pixel = XGetPixel(image, xi, yi);
+                    XQueryColor(d, map, &c);
+                    size_t base = (xi + (yi * w)) * 4;
+                    buf[base + 0] = c.red   / 256;
+                    buf[base + 1] = c.green / 256;
+                    buf[base + 2] = c.blue  / 256;
+                    buf[base + 3] = 255;
+                }
+            }
+    
+            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, buf);
+            free(buf);
+        } else {
+            /* Use image data directly. The alpha value is garbage/unassigned data, but
+               we need to read it because X11 keeps pixel data aligned */
+            buf = (uint8_t*) image->data;
+            /* Data could be 2, 4, or 8 byte aligned, the RGBA format and type (depth)
+               already ensures reads will be properly aligned across scanlines */
+            glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+            GLenum format = image->bitmap_bit_order == LSBFirst ?
+                (!aligned ? GL_BGRA : GL_BGR) :
+                (!aligned ? GL_RGBA : GL_RGB);
+            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, format, type, buf);
+            glPixelStorei(GL_UNPACK_ALIGNMENT, 4); /* restore default */
+        }
+    }
+    if (use_shm) {
+        XShmDetach(d, &shminfo);
+        shmdt(shminfo.shmaddr);
+        shmctl(shminfo.shmid, IPC_RMID, NULL);
     }
 
-    XShmDetach(d, &shminfo);
-    shmdt(shminfo.shmaddr);
-    shmctl(shminfo.shmid, IPC_RMID, NULL);
-
-    XDestroyImage(image);
+    if (image) XDestroyImage(image);
     
     return texture;
 }

xwin.h

@@ -1,5 +1,5 @@
 
-bool xwin_should_render(void);
-void xwin_settype(struct renderer* rd, const char* type);
-void xwin_addstate(struct renderer* rd, const char* state);
+bool xwin_should_render(struct renderer* rd);
+void xwin_settype(struct gl_wcb* wcb, void* impl, const char* type);
+void xwin_addstate(struct gl_wcb* wcb, void* impl, const char* state);
 unsigned int xwin_copyglbg(struct renderer* rd, unsigned int texture);