Implement a global shader parameter passing system and useful shaders

client/shaders/test_shader_1/opengl_fragment.glsl

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+
+uniform sampler2D myTexture;
+uniform vec4 skyBgColor;
+uniform float fogDistance;
+
+varying vec3 vPosition;
+
+void main (void)
+{
+    //vec4 col = vec4(1.0, 0.0, 0.0, 1.0);
+    vec4 col = texture2D(myTexture, vec2(gl_TexCoord[0]));
+	float a = col.a;
+    col *= gl_Color;
+	col = col * col; // SRGB -> Linear
+	col *= 1.8;
+	col.r = 1.0 - exp(1.0 - col.r) / exp(1.0);
+	col.g = 1.0 - exp(1.0 - col.g) / exp(1.0);
+	col.b = 1.0 - exp(1.0 - col.b) / exp(1.0);
+	col = sqrt(col); // Linear -> SRGB
+	if(fogDistance != 0.0){
+		float d = max(0.0, min(vPosition.z / fogDistance * 1.5 - 0.6, 1.0));
+		col = mix(col, skyBgColor, d);
+	}
+    gl_FragColor = vec4(col.r, col.g, col.b, a);
+}