1 /*
2 * Copyright (C) 2011 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 * * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include "config.h"
32
33 #if ENABLE(ACCELERATED_2D_CANVAS)
34
35 #include "ConvolutionShader.h"
36
37 #include "GraphicsContext3D.h"
38 #include "StringExtras.h"
39
40 namespace WebCore {
41
ConvolutionShader(GraphicsContext3D * context,unsigned program,int kernelWidth)42 ConvolutionShader::ConvolutionShader(GraphicsContext3D* context, unsigned program, int kernelWidth)
43 : Shader(context, program)
44 , m_kernelWidth(kernelWidth)
45 , m_matrixLocation(context->getUniformLocation(program, "matrix"))
46 , m_texMatrixLocation(context->getUniformLocation(program, "texMatrix"))
47 , m_kernelLocation(context->getUniformLocation(program, "kernel"))
48 , m_imageLocation(context->getUniformLocation(program, "image"))
49 , m_imageIncrementLocation(context->getUniformLocation(program, "imageIncrement"))
50 , m_positionLocation(context->getAttribLocation(program, "position"))
51 {
52 }
53
create(GraphicsContext3D * context,int kernelWidth)54 PassOwnPtr<ConvolutionShader> ConvolutionShader::create(GraphicsContext3D* context, int kernelWidth)
55 {
56 static const char* vertexShaderRaw =
57 "#define KERNEL_WIDTH %d\n"
58 "uniform mat3 matrix;\n"
59 "uniform mat3 texMatrix;\n"
60 "uniform vec2 imageIncrement;\n"
61 "attribute vec2 position;\n"
62 "varying vec2 imageCoord;\n"
63 "void main() {\n"
64 " vec3 pos = vec3(position, 1.0);\n"
65 " // Offset image coords by half of kernel width, in image texels\n"
66 " gl_Position = vec4(matrix * pos, 1.0);\n"
67 " float scale = (float(KERNEL_WIDTH) - 1.0) / 2.0;\n"
68 " imageCoord = (texMatrix * pos).xy - vec2(scale, scale) * imageIncrement;\n"
69 "}\n";
70 char vertexShaderSource[1024];
71 snprintf(vertexShaderSource, sizeof(vertexShaderSource), vertexShaderRaw, kernelWidth);
72 static const char* fragmentShaderRaw =
73 "#ifdef GL_ES\n"
74 "precision mediump float;\n"
75 "#endif\n"
76 "#define KERNEL_WIDTH %d\n"
77 "uniform sampler2D image;\n"
78 "uniform float kernel[KERNEL_WIDTH];\n"
79 "uniform vec2 imageIncrement;\n"
80 "varying vec2 imageCoord;\n"
81 "void main() {\n"
82 " vec2 coord = imageCoord;\n"
83 " vec4 sum = vec4(0, 0, 0, 0);\n"
84 " for (int i = 0; i < KERNEL_WIDTH; i++) {\n"
85 " sum += texture2D(image, coord) * kernel[i];\n"
86 " coord += imageIncrement;\n"
87 " }\n"
88 " gl_FragColor = sum;\n"
89 "}\n";
90 char fragmentShaderSource[1024];
91 snprintf(fragmentShaderSource, sizeof(fragmentShaderSource), fragmentShaderRaw, kernelWidth);
92
93 unsigned program = loadProgram(context, vertexShaderSource, fragmentShaderSource);
94 if (!program)
95 return 0;
96 return new ConvolutionShader(context, program, kernelWidth);
97 }
98
use(const AffineTransform & transform,const AffineTransform & texTransform,const float * kernel,int kernelWidth,float imageIncrement[2])99 void ConvolutionShader::use(const AffineTransform& transform, const AffineTransform& texTransform, const float* kernel, int kernelWidth, float imageIncrement[2])
100 {
101 m_context->useProgram(m_program);
102 float matrix[9];
103 affineTo3x3(transform, matrix);
104 m_context->uniformMatrix3fv(m_matrixLocation, false /*transpose*/, matrix, 1 /*count*/);
105
106 float texMatrix[9];
107 affineTo3x3(texTransform, texMatrix);
108 m_context->uniformMatrix3fv(m_texMatrixLocation, false /*transpose*/, texMatrix, 1 /*count*/);
109
110 m_context->uniform2f(m_imageIncrementLocation, imageIncrement[0], imageIncrement[1]);
111
112 // For now, we always use texture unit 0. If that ever changes, we should
113 // expose this parameter to the caller.
114 m_context->uniform1i(m_imageLocation, 0);
115 if (kernelWidth > m_kernelWidth)
116 kernelWidth = m_kernelWidth;
117 m_context->uniform1fv(m_kernelLocation, const_cast<float*>(kernel), kernelWidth);
118
119 m_context->vertexAttribPointer(m_positionLocation, 2, GraphicsContext3D::FLOAT, false, 0, 0);
120
121 m_context->enableVertexAttribArray(m_positionLocation);
122 }
123
124 }
125
126 #endif
127