Draw the sun, debug the colour and variable size

[clouds.git] / billboardfrag.glsl

diff --git a/billboardfrag.glsl b/billboardfrag.glsl
index 94d15dcb2f1e477e90ed7cba724dedfcc4f49308..c2e480bf88a930278ffe6f472f8be86c02b1bddd 100644 (file)
--- a/billboardfrag.glsl
+++ b/billboardfrag.glsl
@@ -4,7 +4,18 @@ 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 -- not set, defaults to (0,0,0,0)
        // Af = alpha from fragment, At = alpha from texture
@@ -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