Files
glava/shaders/graph/2.frag
2017-12-09 12:07:49 -08:00

45 lines
1.8 KiB
GLSL

layout(pixel_center_integer) in vec4 gl_FragCoord;
#request uniform "prev" tex
uniform sampler2D tex; /* screen texture */
#request uniform "screen" screen
uniform ivec2 screen; /* screen dimensions */
out vec4 fragment; /* output */
#include ":graph.glsl"
void main() {
fragment = texture(tex, vec2(gl_FragCoord.x / screen.x, gl_FragCoord.y / screen.y));
vec4
a0 = texture(tex, vec2((gl_FragCoord.x + 1) / screen.x, (gl_FragCoord.y + 0) / screen.y)),
a1 = texture(tex, vec2((gl_FragCoord.x + 1) / screen.x, (gl_FragCoord.y + 1) / screen.y)),
a2 = texture(tex, vec2((gl_FragCoord.x + 0) / screen.x, (gl_FragCoord.y + 1) / screen.y)),
a3 = texture(tex, vec2((gl_FragCoord.x + 1) / screen.x, (gl_FragCoord.y + 0) / screen.y)),
a4 = texture(tex, vec2((gl_FragCoord.x - 1) / screen.x, (gl_FragCoord.y - 0) / screen.y)),
a5 = texture(tex, vec2((gl_FragCoord.x - 1) / screen.x, (gl_FragCoord.y - 1) / screen.y)),
a6 = texture(tex, vec2((gl_FragCoord.x - 0) / screen.x, (gl_FragCoord.y - 1) / screen.y)),
a7 = texture(tex, vec2((gl_FragCoord.x - 1) / screen.x, (gl_FragCoord.y - 0) / screen.y));
vec4 avg = (a0 + a1 + a2 + a3 + a4 + a5 + a6 + a7) / 8.0;
if (avg.a > 0){
#if INVERT > 0
#define EDGE_CHECK (gl_FragCoord.y != 0)
#define TEDGE_CHECK (gl_FragCoord.y != screen.y - 1)
#else
#define EDGE_CHECK (gl_FragCoord.y != screen.y - 1)
#define TEDGE_CHECK (gl_FragCoord.y != 0)
#endif
if (fragment.a <= 0 && EDGE_CHECK) {
/* outline */
fragment = OUTLINE;
} else if (avg.a < 1 && TEDGE_CHECK) {
/* creates a nice 'glint' along the edge of the spectrum */
fragment.rgb *= avg.a * 2;
}
}
}