65 lines
2.0 KiB
GLSL
65 lines
2.0 KiB
GLSL
#version 330 core
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// Interpolated values from the vertex shaders
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in vec2 UV;
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in vec3 Position_worldspace;
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in vec3 Normal_cameraspace;
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in vec3 EyeDirection_cameraspace;
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in vec3 LightDirection_cameraspace;
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// Ouput data
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out vec3 color;
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// Values that stay constant for the whole mesh.
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uniform sampler2D tAlbedo;
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uniform mat4 MV;
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uniform vec3 LightPosition_worldspace;
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void main(){
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// Light emission properties
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// You probably want to put them as uniforms
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vec3 LightColor = vec3(1,1,1);
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float LightPower = 200.0f;
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// Material properties
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vec3 MaterialDiffuseColor = texture( tAlbedo, UV ).rgb;
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vec3 MaterialAmbientColor = vec3(0.1,0.1,0.1) * MaterialDiffuseColor;
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vec3 MaterialSpecularColor = vec3(0.03,0.03,0.03);
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// Distance to the light
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float distance = length( LightPosition_worldspace - Position_worldspace );
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// Normal of the computed fragment, in camera space
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vec3 n = normalize( Normal_cameraspace );
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// Direction of the light (from the fragment to the light)
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vec3 l = normalize( LightDirection_cameraspace );
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// Cosine of the angle between the normal and the light direction,
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// clamped above 0
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// - light is at the vertical of the triangle -> 1
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// - light is perpendicular to the triangle -> 0
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// - light is behind the triangle -> 0
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float cosTheta = clamp( dot( n,l ), 0,1 );
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// Eye vector (towards the camera)
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vec3 E = normalize(EyeDirection_cameraspace);
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// Direction in which the triangle reflects the light
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vec3 R = reflect(-l,n);
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// Cosine of the angle between the Eye vector and the Reflect vector,
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// clamped to 0
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// - Looking into the reflection -> 1
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// - Looking elsewhere -> < 1
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float cosAlpha = clamp( dot( E,R ), 0,1 );
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color =
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// Ambient : simulates indirect lighting
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MaterialAmbientColor +
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// Diffuse : "color" of the object
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MaterialDiffuseColor * LightColor * LightPower * cosTheta / (distance*distance)
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+
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// Specular : reflective highlight, like a mirror
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MaterialSpecularColor * LightColor * LightPower * pow(cosAlpha,5) / (distance*distance);
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}
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