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author | Samuel Rødal <sroedal@trolltech.com> | 2009-06-25 10:38:38 (GMT) |
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committer | Samuel Rødal <sroedal@trolltech.com> | 2009-06-25 11:19:39 (GMT) |
commit | e3886938f27da1ed460de83235d9fd3d5abd4713 (patch) | |
tree | f29e53670a85ededd2a6f41a2976873cb316ecda /src/opengl/gl2paintengineex | |
parent | 0c1be3042e27bf1980afa14eb6b0990b78bdd15f (diff) | |
download | Qt-e3886938f27da1ed460de83235d9fd3d5abd4713.zip Qt-e3886938f27da1ed460de83235d9fd3d5abd4713.tar.gz Qt-e3886938f27da1ed460de83235d9fd3d5abd4713.tar.bz2 |
Fixed buggy clipping when using projective transforms in GL 2 engine.
The gl_Position x, y, and z coordinates are always divided by the
homogenuous w coordinate to yield the final coordinates. Since we want
the depth to be constant for the whole item we need to premultiply it by
the w-coordinate. We can do this in the main() function in the vertex
programs since all the vertex programs use the depth uniform, thus
simplifying the programs a bit.
Reviewed-by: Trond
Diffstat (limited to 'src/opengl/gl2paintengineex')
-rw-r--r-- | src/opengl/gl2paintengineex/qglengineshadersource_p.h | 18 |
1 files changed, 4 insertions, 14 deletions
diff --git a/src/opengl/gl2paintengineex/qglengineshadersource_p.h b/src/opengl/gl2paintengineex/qglengineshadersource_p.h index 4959b60..4e32f91 100644 --- a/src/opengl/gl2paintengineex/qglengineshadersource_p.h +++ b/src/opengl/gl2paintengineex/qglengineshadersource_p.h @@ -64,19 +64,23 @@ QT_MODULE(OpenGL) static const char* const qglslMainVertexShader = "\ + uniform highp float depth;\ void setPosition();\ void main(void)\ {\ setPosition();\ + gl_Position.z = depth * gl_Position.w;\ }"; static const char* const qglslMainWithTexCoordsVertexShader = "\ attribute lowp vec2 textureCoordArray; \ varying lowp vec2 textureCoords; \ + uniform highp float depth;\ void setPosition();\ void main(void) \ {\ setPosition();\ + gl_Position.z = depth * gl_Position.w;\ textureCoords = textureCoordArray; \ }"; @@ -84,20 +88,16 @@ static const char* const qglslMainWithTexCoordsVertexShader = "\ static const char* const qglslPositionOnlyVertexShader = "\ attribute highp vec4 vertexCoordsArray;\ uniform highp mat4 pmvMatrix;\ - uniform highp float depth;\ void setPosition(void)\ {\ gl_Position = pmvMatrix * vertexCoordsArray;\ - gl_Position.z = depth;\ }"; static const char* const qglslUntransformedPositionVertexShader = "\ attribute highp vec4 vertexCoordsArray;\ - uniform highp float depth;\ void setPosition(void)\ {\ gl_Position = vertexCoordsArray;\ - gl_Position.z = depth;\ }"; // Pattern Brush - This assumes the texture size is 8x8 and thus, the inverted size is 0.125 @@ -108,11 +108,9 @@ static const char* const qglslPositionWithPatternBrushVertexShader = "\ uniform mediump vec2 invertedTextureSize; \ uniform mediump mat3 brushTransform; \ varying mediump vec2 patternTexCoords; \ - uniform highp float depth;\ void setPosition(void) { \ gl_Position = pmvMatrix * vertexCoordsArray;\ gl_Position.xy = gl_Position.xy / gl_Position.w; \ - gl_Position.z = depth;\ mediump vec2 viewportCoords = (gl_Position.xy + 1.0) * halfViewportSize; \ mediump vec3 hTexCoords = brushTransform * vec3(viewportCoords, 1); \ mediump float invertedHTexCoordsZ = 1.0 / hTexCoords.z; \ @@ -142,11 +140,9 @@ static const char* const qglslPositionWithLinearGradientBrushVertexShader = "\ uniform highp vec3 linearData; \ uniform highp mat3 brushTransform; \ varying mediump float index ; \ - uniform highp float depth;\ void setPosition() { \ gl_Position = pmvMatrix * vertexCoordsArray;\ gl_Position.xy = gl_Position.xy / gl_Position.w; \ - gl_Position.z = depth;\ mediump vec2 viewportCoords = (gl_Position.xy + 1.0) * halfViewportSize; \ mediump vec3 hTexCoords = brushTransform * vec3(viewportCoords, 1); \ mediump float invertedHTexCoordsZ = 1.0 / hTexCoords.z; \ @@ -174,12 +170,10 @@ static const char* const qglslPositionWithConicalGradientBrushVertexShader = "\ uniform mediump vec2 halfViewportSize; \ uniform highp mat3 brushTransform; \ varying highp vec2 A; \ - uniform highp float depth;\ void setPosition(void)\ {\ gl_Position = pmvMatrix * vertexCoordsArray;\ gl_Position.xy = gl_Position.xy / gl_Position.w; \ - gl_Position.z = depth; \ mediump vec2 viewportCoords = (gl_Position.xy + 1.0) * halfViewportSize; \ mediump vec3 hTexCoords = brushTransform * vec3(viewportCoords, 1); \ mediump float invertedHTexCoordsZ = 1.0 / hTexCoords.z; \ @@ -215,12 +209,10 @@ static const char* const qglslPositionWithRadialGradientBrushVertexShader = "\ uniform highp vec2 fmp; \ varying highp float b; \ varying highp vec2 A; \ - uniform highp float depth;\ void setPosition(void) \ {\ gl_Position = pmvMatrix * vertexCoordsArray;\ gl_Position.xy = gl_Position.xy / gl_Position.w; \ - gl_Position.z = depth; \ mediump vec2 viewportCoords = (gl_Position.xy + 1.0) * halfViewportSize; \ mediump vec3 hTexCoords = brushTransform * vec3(viewportCoords, 1); \ mediump float invertedHTexCoordsZ = 1.0 / hTexCoords.z; \ @@ -254,11 +246,9 @@ static const char* const qglslPositionWithTextureBrushVertexShader = "\ uniform mediump vec2 invertedTextureSize; \ uniform mediump mat3 brushTransform; \ varying mediump vec2 brushTextureCoords; \ - uniform highp float depth;\ void setPosition(void) { \ gl_Position = pmvMatrix * vertexCoordsArray;\ gl_Position.xy = gl_Position.xy / gl_Position.w; \ - gl_Position.z = depth; \ mediump vec2 viewportCoords = (gl_Position.xy + 1.0) * halfViewportSize; \ mediump vec3 hTexCoords = brushTransform * vec3(viewportCoords, 1); \ mediump float invertedHTexCoordsZ = 1.0 / hTexCoords.z; \ |