Bloom (#12791)

Adds configurable light exposure control and bloom effect (light bleeding) with client-side settings.

client/shaders/blur_h/opengl_fragment.glsl

@@ -0,0 +1,29 @@
+#define rendered texture0
+
+uniform sampler2D rendered;
+uniform vec2 texelSize0;
+uniform mediump float bloomRadius = 3.0;
+
+#ifdef GL_ES
+varying mediump vec2 varTexCoord;
+#else
+centroid varying vec2 varTexCoord;
+#endif
+
+void main(void)
+{
+	// kernel distance and linear size
+	mediump float n = 2. * bloomRadius + 1.;
+
+	vec2 uv = varTexCoord.st - vec2(bloomRadius * texelSize0.x, 0.);
+	vec4 color = vec4(0.);
+	mediump float sum = 0.;
+	for (mediump float i = 0.; i < n; i++) {
+		mediump float weight = pow(1. - (abs(i / bloomRadius - 1.)), 1.3);
+		color += texture2D(rendered, uv).rgba * weight;
+		sum += weight;
+		uv += vec2(texelSize0.x, 0.);
+	}
+	color /= sum;
+	gl_FragColor = vec4(color.rgb, 1.0); // force full alpha to avoid holes in the image.
+}

client/shaders/blur_h/opengl_vertex.glsl

@@ -0,0 +1,11 @@
+#ifdef GL_ES
+varying mediump vec2 varTexCoord;
+#else
+centroid varying vec2 varTexCoord;
+#endif
+
+void main(void)
+{
+	varTexCoord.st = inTexCoord0.st;
+	gl_Position = inVertexPosition;
+}