Files
processing4/java/examples/Topics/Shaders/EdgeDetect/data/edges.glsl
2013-02-06 17:11:17 -05:00

41 lines
1.5 KiB
GLSL

#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif
#define PROCESSING_TEXTURE_SHADER
uniform sampler2D texture;
uniform vec2 texOffset;
varying vec4 vertColor;
varying vec4 vertTexCoord;
void main(void) {
// Grouping texcoord variables in order to make it work in the GMA 950. See post #13
// in this thread:
// http://www.idevgames.com/forums/thread-3467.html
vec2 tc0 = vertTexCoord.st + vec2(-texOffset.s, -texOffset.t);
vec2 tc1 = vertTexCoord.st + vec2( 0.0, -texOffset.t);
vec2 tc2 = vertTexCoord.st + vec2(+texOffset.s, -texOffset.t);
vec2 tc3 = vertTexCoord.st + vec2(-texOffset.s, 0.0);
vec2 tc4 = vertTexCoord.st + vec2( 0.0, 0.0);
vec2 tc5 = vertTexCoord.st + vec2(+texOffset.s, 0.0);
vec2 tc6 = vertTexCoord.st + vec2(-texOffset.s, +texOffset.t);
vec2 tc7 = vertTexCoord.st + vec2( 0.0, +texOffset.t);
vec2 tc8 = vertTexCoord.st + vec2(+texOffset.s, +texOffset.t);
vec4 col0 = texture2D(texture, tc0);
vec4 col1 = texture2D(texture, tc1);
vec4 col2 = texture2D(texture, tc2);
vec4 col3 = texture2D(texture, tc3);
vec4 col4 = texture2D(texture, tc4);
vec4 col5 = texture2D(texture, tc5);
vec4 col6 = texture2D(texture, tc6);
vec4 col7 = texture2D(texture, tc7);
vec4 col8 = texture2D(texture, tc8);
vec4 sum = 8.0 * col4 - (col0 + col1 + col2 + col3 + col5 + col6 + col7 + col8);
gl_FragColor = vec4(sum.rgb, 1.0) * vertColor;
}