diff options
Diffstat (limited to 'examples/qt3d/tessellation-modes/shaders/phongwireframe.frag')
-rw-r--r-- | examples/qt3d/tessellation-modes/shaders/phongwireframe.frag | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/examples/qt3d/tessellation-modes/shaders/phongwireframe.frag b/examples/qt3d/tessellation-modes/shaders/phongwireframe.frag new file mode 100644 index 000000000..4fd62007d --- /dev/null +++ b/examples/qt3d/tessellation-modes/shaders/phongwireframe.frag @@ -0,0 +1,108 @@ +#version 400 core + +uniform struct LightInfo { + vec4 position; + vec3 intensity; +} light; + +uniform struct LineInfo { + float width; + vec4 color; +} line; + +uniform vec3 ka; // Ambient reflectivity +uniform vec3 kd; // Diffuse reflectivity +uniform vec3 ks; // Specular reflectivity +uniform float shininess; // Specular shininess factor + +in WireframeVertex { + vec3 position; + vec3 normal; + noperspective vec4 edgeA; + noperspective vec4 edgeB; + flat int configuration; +} fs_in; + +out vec4 fragColor; + +vec3 adsModel( const in vec3 pos, const in vec3 n ) +{ + // Calculate the vector from the light to the fragment + vec3 s = normalize( vec3( light.position ) - pos ); + + // Calculate the vector from the fragment to the eye position (the + // origin since this is in "eye" or "camera" space + vec3 v = normalize( -pos ); + + // Refleft the light beam using the normal at this fragment + vec3 r = reflect( -s, n ); + + // Calculate the diffus component + vec3 diffuse = vec3( max( dot( s, n ), 0.0 ) ); + + // Calculate the specular component + vec3 specular = vec3( pow( max( dot( r, v ), 0.0 ), shininess ) ); + + // Combine the ambient, diffuse and specular contributions + return light.intensity * ( ka + kd * diffuse + ks * specular ); +} + +vec4 shadeLine( const in vec4 color ) +{ + // Find the smallest distance between the fragment and a triangle edge + float d; + if ( fs_in.configuration == 0 ) + { + // Common configuration + d = min( fs_in.edgeA.x, fs_in.edgeA.y ); + d = min( d, fs_in.edgeA.z ); + } + else + { + // Handle configuration where screen space projection breaks down + // Compute and compare the squared distances + vec2 AF = gl_FragCoord.xy - fs_in.edgeA.xy; + float sqAF = dot( AF, AF ); + float AFcosA = dot( AF, fs_in.edgeA.zw ); + d = abs( sqAF - AFcosA * AFcosA ); + + vec2 BF = gl_FragCoord.xy - fs_in.edgeB.xy; + float sqBF = dot( BF, BF ); + float BFcosB = dot( BF, fs_in.edgeB.zw ); + d = min( d, abs( sqBF - BFcosB * BFcosB ) ); + + // Only need to care about the 3rd edge for some configurations. + if ( fs_in.configuration == 1 || fs_in.configuration == 2 || fs_in.configuration == 4 ) + { + float AFcosA0 = dot( AF, normalize( fs_in.edgeB.xy - fs_in.edgeA.xy ) ); + d = min( d, abs( sqAF - AFcosA0 * AFcosA0 ) ); + } + + d = sqrt( d ); + } + + // Blend between line color and phong color + float mixVal; + if ( d < line.width - 1.0 ) + { + mixVal = 1.0; + } + else if ( d > line.width + 1.0 ) + { + mixVal = 0.0; + } + else + { + float x = d - ( line.width - 1.0 ); + mixVal = exp2( -2.0 * ( x * x ) ); + } + + return mix( color, line.color, mixVal ); +} + +void main() +{ + // Calculate the color from the phong model + vec4 color = vec4( adsModel( fs_in.position, normalize( fs_in.normal ) ), 1.0 ); + fragColor = shadeLine( color ); +} |