d27174028e
Use two-pass rendering for some shaders to reduce the cost of expensive shaders. Implement some material animations using a shader uniform. Eliminate use of gl_FrontFacing. It's too buggy on ATI/ Macintosh.
48 lines
1.6 KiB
C++
48 lines
1.6 KiB
C++
// -*-C++-*-
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// Ambient term comes in gl_Color.rgb.
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varying vec4 diffuse_term;
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varying vec3 normal;
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varying float fogCoord;
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uniform sampler2D texture;
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float luminance(vec3 color)
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{
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return dot(vec3(0.212671, 0.715160, 0.072169), color);
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}
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void main()
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{
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vec3 n, halfV;
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float NdotL, NdotHV, fogFactor;
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vec4 color = gl_FrontLightModelProduct.sceneColor + gl_Color;
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vec3 lightDir = gl_LightSource[0].position.xyz;
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vec3 halfVector = gl_LightSource[0].halfVector.xyz;
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vec4 texel;
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vec4 fragColor;
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vec4 specular = vec4(0.0);
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n = normalize(normal);
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// If gl_Color.a == 0, this is a back-facing polygon and the
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// normal should be reversed.
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n = (2.0 * gl_Color.a - 1.0) * n;
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NdotL = max(dot(n, lightDir), 0.0);
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if (NdotL > 0.0) {
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color += diffuse_term * NdotL;
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halfV = normalize(halfVector);
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NdotHV = max(dot(n, halfV), 0.0);
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if (gl_FrontMaterial.shininess > 0.0)
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specular.rgb = (gl_FrontMaterial.specular.rgb
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* gl_LightSource[0].specular.rgb
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* pow(NdotHV, gl_FrontMaterial.shininess));
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}
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color.a = diffuse_term.a;
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// This shouldn't be necessary, but our lighting becomes very
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// saturated. Clamping the color before modulating by the texture
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// is closer to what the OpenGL fixed function pipeline does.
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color = clamp(color, 0.0, 1.0);
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texel = texture2D(texture, gl_TexCoord[0].st);
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fragColor = color * texel + specular;
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fogFactor = exp(-gl_Fog.density * gl_Fog.density * fogCoord * fogCoord);
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gl_FragColor = mix(gl_Fog.color, fragColor, fogFactor);
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}
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