Add blurring of lightmap (and refactoring)

shader/blur.frag

@@ -0,0 +1,38 @@
+#version 430 core
+in vec2 vTexPos;
+out vec4 fColor;
+
+uniform vec2 winSize;
+uniform sampler2D screenTexture;
+
+const float hOff = 1.0 / winSize.x;
+const float vOff = 1.0 / winSize.y;
+//const float verOff = 1.0 / 600.0;
+
+//const float kernel[9] = float[](
+//    0.025,0.05,0.1, 0.2, 0.25, 0.2,0.1, 0.05, 0.025
+//   0.1,0.1,0.1,0.1,0.2,0.1,0.1,0.1,0.1
+//    );
+const float kernel[5] = float[](
+         0.175,
+    0.175,0.3,0.175,
+         0.175
+    );
+const float off[5] = float[](
+         vOff,
+    -hOff,0.0,hOff,
+         -vOff
+    );
+
+void main()
+{
+    vec4 sampleTex[5];
+    for(int i=0; i<5; i++)
+    {
+        sampleTex[i] = vec4(texture(screenTexture, vTexPos + off[i]));
+    }
+    vec4 col = vec4(0,0,0,0);
+    for (int i = 0; i < 5; i++)
+        col += sampleTex[i] * kernel[i];
+    fColor = col;
+}