Some typo fixes

[clouds.git] / billboardfrag.glsl

diff --git a/billboardfrag.glsl b/billboardfrag.glsl
index 2349e4dfef4610558042a9f6b8315e1ac217800a..b4cfd511464569ea23c577cda41a5b261c7ba288 100644 (file)
--- 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, 0), 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;
@@ -14,8 +25,13 @@ void main() {
     // GL_MODULATE: C
     // C = Cf * Ct
     // A = Af * At
-               FragColor = color * f;
+    // the +0.06 is a hack to get lighter clouds!
+    // can be thought of as ambient light
+    FragColor = color * (f + 0.02);
   } 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