1 files changed, 55 insertions, 0 deletions
diff --git a/src/renderergl2/glsl/calclevels4x_fp.glsl b/src/renderergl2/glsl/calclevels4x_fp.glsl
new file mode 100644
index 00000000..c8cf06c7
--- /dev/null
+++ b/src/renderergl2/glsl/calclevels4x_fp.glsl
@@ -0,0 +1,55 @@
+uniform sampler2D u_TextureMap;
+
+uniform vec4      u_Color;
+
+uniform vec2      u_InvTexRes;
+varying vec2      var_TexCoords;
+
+const vec3  LUMINANCE_VECTOR =   vec3(0.2125, 0.7154, 0.0721); //vec3(0.299, 0.587, 0.114);
+
+vec3 GetValues(vec2 offset, vec3 current)
+{
+	vec3 minAvgMax;
+	vec2 tc = var_TexCoords + u_InvTexRes * offset; minAvgMax = texture2D(u_TextureMap, tc).rgb;
+
+#ifdef FIRST_PASS
+	float lumi = max(dot(LUMINANCE_VECTOR, minAvgMax), 0.000001);
+	float loglumi = clamp(log2(lumi), -10.0, 10.0);
+	minAvgMax = vec3(loglumi * 0.05 + 0.5);
+#endif
+
+	return vec3(min(current.x, minAvgMax.x), current.y + minAvgMax.y, max(current.z, minAvgMax.z));
+}
+
+void main()
+{
+	vec3 current = vec3(1.0, 0.0, 0.0);
+
+#ifdef FIRST_PASS
+	current = GetValues(vec2( 0.0,  0.0), current);
+#else
+	current = GetValues(vec2(-1.5, -1.5), current);
+	current = GetValues(vec2(-0.5, -1.5), current);
+	current = GetValues(vec2( 0.5, -1.5), current);
+	current = GetValues(vec2( 1.5, -1.5), current);
+	
+	current = GetValues(vec2(-1.5, -0.5), current);
+	current = GetValues(vec2(-0.5, -0.5), current);
+	current = GetValues(vec2( 0.5, -0.5), current);
+	current = GetValues(vec2( 1.5, -0.5), current);
+	
+	current = GetValues(vec2(-1.5,  0.5), current);
+	current = GetValues(vec2(-0.5,  0.5), current);
+	current = GetValues(vec2( 0.5,  0.5), current);
+	current = GetValues(vec2( 1.5,  0.5), current);
+
+	current = GetValues(vec2(-1.5,  1.5), current);
+	current = GetValues(vec2(-0.5,  1.5), current);
+	current = GetValues(vec2( 0.5,  1.5), current);
+	current = GetValues(vec2( 1.5,  1.5), current);
+
+	current.y *= 0.0625;
+#endif
+
+	gl_FragColor = vec4(current, 1.0f);
+}