X-Git-Url: https://git.lukelau.me/?a=blobdiff_plain;f=billboardfrag.glsl;h=c2e480bf88a930278ffe6f472f8be86c02b1bddd;hb=e4bfe561fba2c32bf5ecdbf6a96067676ab313a2;hp=2349e4dfef4610558042a9f6b8315e1ac217800a;hpb=31f19438c73b207f506ba0b1187d2de75c166a5b;p=clouds.git

diff --git a/billboardfrag.glsl b/billboardfrag.glsl
index 2349e4d..c2e480b 100644
--- a/billboardfrag.glsl
+++ b/billboardfrag.glsl
@@ -4,9 +4,20 @@ uniform sampler2D tex;
 in vec2 texCoord;
 out vec4 FragColor;
 uniform bool modulate;
+uniform bool debug;
+uniform bool debugColor;
+uniform float debugVal;
 void main() {
+  if (debugColor) {
+    FragColor = color;
+    return;
+  }
+  if (debug) {
+    FragColor = mix(vec4(1, 1, 1, 1), vec4(1, 0, 0, 1), debugVal);
+    return;
+  }
 	// Cf = color from fragment, Ct = color from texture
-	// Cc = color from texture environment(?) assume to be 0?
+	// Cc = color from texture environment -- not set, defaults to (0,0,0,0)
 	// Af = alpha from fragment, At = alpha from texture
 	// C = output color, A = output alpha
 	float f = texture(tex, texCoord).r;
@@ -16,6 +27,9 @@ void main() {
 		// A = Af * At				
 		FragColor = color * f;
 	} else {
+        // "That is, the colors in the frame buffer are multiplied by the
+        // attenuation ratio of the billboard texture and then the colors in
+        // the texture are added"
 		// GL_BLEND:
 		// C = Cf * (1-Ct) + Cc * Ct
 		// A = Af * At