Update/merge examples back into main repo (#192)

Examples/resources/shaders/glsl120/predator.fs

@@ -0,0 +1,29 @@
+#version 120
+
+// Input vertex attributes (from vertex shader)
+varying vec2 fragTexCoord;
+varying vec4 fragColor;
+
+// Input uniform values
+uniform sampler2D texture0;
+uniform vec4 colDiffuse;
+
+// NOTE: Add here your custom variables
+
+void main()
+{
+    vec3 color = texture2D(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 = (color.r + color.g + color.b)/3.0;
+
+    vec3 tc = vec3(0.0, 0.0, 0.0);
+
+    if (lum < 0.5) tc = mix(colors[0], colors[1], lum/0.5);
+    else tc = mix(colors[1], colors[2], (lum - 0.5)/0.5);
+
+    gl_FragColor = vec4(tc, 1.0);
+}