VBO-related optimizations and improvements (#14395)

client/shaders/cloud_shader/opengl_fragment.glsl

@@ -0,0 +1,17 @@
+uniform vec4 fogColor;
+uniform float fogDistance;
+uniform float fogShadingParameter;
+varying vec3 eyeVec;
+
+varying lowp vec4 varColor;
+
+void main(void)
+{
+	vec4 col = varColor;
+
+	float clarity = clamp(fogShadingParameter
+		- fogShadingParameter * length(eyeVec) / fogDistance, 0.0, 1.0);
+	col.rgb = mix(fogColor.rgb, col.rgb, clarity);
+
+	gl_FragColor = col;
+}

client/shaders/cloud_shader/opengl_vertex.glsl

@@ -0,0 +1,21 @@
+uniform vec4 emissiveColor;
+
+varying lowp vec4 varColor;
+
+varying vec3 eyeVec;
+
+void main(void)
+{
+	gl_Position = mWorldViewProj * inVertexPosition;
+
+#ifdef GL_ES
+	vec4 color = inVertexColor.bgra;
+#else
+	vec4 color = inVertexColor;
+#endif
+
+	color *= emissiveColor;
+	varColor = color;
+
+	eyeVec = -(mWorldView * inVertexPosition).xyz;
+}

client/shaders/stars_shader/opengl_fragment.glsl

@@ -1,6 +1,6 @@
-uniform vec4 starColor;
+uniform vec4 emissiveColor;
 
 void main(void)
 {
-	gl_FragColor = starColor;
+	gl_FragColor = emissiveColor;
 }