Fix shaders

examples/shaders/postprocessing/glsl330/predator.fs

@@ -0,0 +1,32 @@
+#version 330
+
+// Input vertex attributes (from vertex shader)
+in vec2 fragTexCoord;
+in vec4 fragColor;
+
+// Input uniform values
+uniform sampler2D texture0;
+uniform vec4 colDiffuse;
+
+// Output fragment color
+out vec4 finalColor;
+
+// NOTE: Add here your custom variables
+
+void main()
+{
+    // Texel color fetching from texture sampler
+    vec3 texelColor = texture(texture0, fragTexCoord).rgb;
+    vec3 colors[3];
+    colors[0] = vec3(0.0, 0.0, 1.0);
+    colors[1] = vec3(1.0, 1.0, 0.0);
+    colors[2] = vec3(1.0, 0.0, 0.0);
+    
+    float lum = (texelColor.r + texelColor.g + texelColor.b)/3.0;
+    
+    int ix = (lum < 0.5)? 0:1;
+    
+    vec3 tc = mix(colors[ix], colors[ix + 1], (lum - float(ix)*0.5)/0.5);
+    
+    finalColor = vec4(tc, 1.0);
+}