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author | Laszlo Agocs <laszlo.agocs@theqtcompany.com> | 2015-03-04 16:05:02 +0100 |
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committer | Laszlo Agocs <laszlo.agocs@theqtcompany.com> | 2015-03-04 15:21:01 +0000 |
commit | c82207d54c76d8b66be010bfa63e45f9507891fa (patch) | |
tree | 8d112e96bc1fa42dbc49907f53d71fa5b893869a /examples/qt3d/wave/shaders/ribbonwireframe.frag | |
parent | 8bff6813ee2e7a59d27bd8639dc9a6e23287a0c8 (diff) |
Move the examples under a qt3d subdir
Modules cannot have their examples in the top-level examples directory because
in the pre-built packages all modules' examples are merged together.
Change-Id: I80fdbb8f1ec6f3d8fd793e4d856e705000237127
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>
Diffstat (limited to 'examples/qt3d/wave/shaders/ribbonwireframe.frag')
-rw-r--r-- | examples/qt3d/wave/shaders/ribbonwireframe.frag | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/examples/qt3d/wave/shaders/ribbonwireframe.frag b/examples/qt3d/wave/shaders/ribbonwireframe.frag new file mode 100644 index 000000000..659f00a8a --- /dev/null +++ b/examples/qt3d/wave/shaders/ribbonwireframe.frag @@ -0,0 +1,98 @@ +#version 330 core + +in WireframeVertex { + vec3 position; + vec3 normal; + noperspective vec4 edgeA; + noperspective vec4 edgeB; + flat int configuration; +} fs_in; + +out vec4 fragColor; + +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 + +vec3 rimLightModel( 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 diffuse component, which for rim lighting it 1 minus s dot n + // rather than s dot n as for standard diffuse lighting + float sDotN = dot( s, n ); + vec3 diffuse = vec3( 1.0 - max( sDotN, 0.0 ) ); + + // Combine the ambient, diffuse and specular contributions + return light.intensity * ( ka + kd * diffuse ); +} + +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 shaded 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() +{ + vec3 n = gl_FrontFacing ? fs_in.normal : -fs_in.normal; + vec4 color = vec4( rimLightModel( fs_in.position, normalize( n ) ), 1.0 ); + fragColor = shadeLine( color ); +} |