diff options
| -rw-r--r-- | progs/glsl/points.c | 22 |
1 files changed, 13 insertions, 9 deletions
diff --git a/progs/glsl/points.c b/progs/glsl/points.c index 2dc0670c606..85115de504a 100644 --- a/progs/glsl/points.c +++ b/progs/glsl/points.c @@ -218,10 +218,13 @@ CheckLink(GLuint prog) static void Init(void) { - /* Fragment shader: compute distance of fragment from center of point, - * if dist > 1, discard - * if dist < k, coverage = 1 - * else, coverage = func(dist) + /* Fragment shader: compute distance of fragment from center of point + * (we're using texcoords but another varying could be used). + * if dist > 1, discard (coverage==0) + * if dist < k, coverage = 1 + * else, coverage = func(dist) + * Note: length() uses sqrt() and may be expensive. The distance could + * be squared instead (with adjustments to the threshold (k) test) */ static const char *fragShaderText = "void main() {\n" @@ -238,15 +241,16 @@ Init(void) " gl_FragColor.a = cover; \n" "}\n"; /* Vertex shader: compute new vertex position based on incoming vertex pos, - * texcoords and inverse viewport scale factor. + * texcoords, point size, and inverse viewport scale factor. + * Note: should compute point size attenuation here too. */ static const char *vertShaderText = "uniform vec2 viewportInv; \n" "void main() {\n" - " vec4 p = gl_ModelViewProjectionMatrix * gl_Vertex;\n" - " vec2 scale2 = viewportInv * gl_Point.size; \n" - " gl_Position.xy = p.xy + gl_MultiTexCoord0.xy * scale2 * p.w; \n" - " gl_Position.zw = p.zw; \n" + " vec4 pos = gl_ModelViewProjectionMatrix * gl_Vertex;\n" + " gl_Position.xy = pos.xy + gl_MultiTexCoord0.xy * viewportInv \n" + " * gl_Point.size * pos.w; \n" + " gl_Position.zw = pos.zw; \n" " gl_TexCoord[0] = gl_MultiTexCoord0; \n" " gl_FrontColor = gl_Color; \n" "}\n"; |