1 files changed, 125 insertions, 0 deletions
diff --git a/Source/WebCore/platform/graphics/gpu/ConvolutionShader.cpp b/Source/WebCore/platform/graphics/gpu/ConvolutionShader.cpp
new file mode 100644
index 0000000..f0b6bd9
--- /dev/null
+++ b/Source/WebCore/platform/graphics/gpu/ConvolutionShader.cpp
@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2011 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+
+#if ENABLE(ACCELERATED_2D_CANVAS)
+
+#include "ConvolutionShader.h"
+
+#include "GraphicsContext3D.h"
+#include "StringExtras.h"
+
+namespace WebCore {
+
+ConvolutionShader::ConvolutionShader(GraphicsContext3D* context, unsigned program, int kernelWidth)
+    : Shader(context, program)
+    , m_kernelWidth(kernelWidth)
+    , m_matrixLocation(context->getUniformLocation(program, "matrix"))
+    , m_texMatrixLocation(context->getUniformLocation(program, "texMatrix"))
+    , m_kernelLocation(context->getUniformLocation(program, "kernel"))
+    , m_imageLocation(context->getUniformLocation(program, "image"))
+    , m_imageIncrementLocation(context->getUniformLocation(program, "imageIncrement"))
+    , m_positionLocation(context->getAttribLocation(program, "position"))
+{
+}
+
+PassOwnPtr<ConvolutionShader> ConvolutionShader::create(GraphicsContext3D* context, int kernelWidth)
+{
+    static const char* vertexShaderRaw =
+        "#define KERNEL_WIDTH %d\n"
+        "uniform mat3 matrix;\n"
+        "uniform mat3 texMatrix;\n"
+        "uniform vec2 imageIncrement;\n"
+        "attribute vec3 position;\n"
+        "varying vec2 imageCoord;\n"
+        "void main() {\n"
+        "    // Offset image coords by half of kernel width, in image texels\n"
+        "    gl_Position = vec4(matrix * position, 1.0);\n"
+        "    float scale = (float(KERNEL_WIDTH) - 1.0) / 2.0;\n"
+        "    imageCoord = (texMatrix * position).xy - vec2(scale, scale) * imageIncrement;\n"
+        "}\n";
+    char vertexShaderSource[1024];
+    snprintf(vertexShaderSource, sizeof(vertexShaderSource), vertexShaderRaw, kernelWidth);
+    static const char* fragmentShaderRaw =
+        "#ifdef GL_ES\n"
+        "precision mediump float;\n"
+        "#endif\n"
+        "#define KERNEL_WIDTH %d\n"
+        "uniform sampler2D image;\n"
+        "uniform float kernel[KERNEL_WIDTH];\n"
+        "uniform vec2 imageIncrement;\n"
+        "varying vec2 imageCoord;\n"
+        "void main() {\n"
+        "    vec2 coord = imageCoord;\n"
+        "    vec4 sum = vec4(0, 0, 0, 0);\n"
+        "    for (int i = 0; i < KERNEL_WIDTH; i++) {\n"
+        "      sum += texture2D(image, coord) * kernel[i];\n"
+        "      coord += imageIncrement;\n"
+        "    }\n"
+        "    gl_FragColor = sum;\n"
+        "}\n";
+    char fragmentShaderSource[1024];
+    snprintf(fragmentShaderSource, sizeof(fragmentShaderSource), fragmentShaderRaw, kernelWidth);
+
+    unsigned program = loadProgram(context, vertexShaderSource, fragmentShaderSource);
+    if (!program)
+        return 0;
+    return new ConvolutionShader(context, program, kernelWidth);
+}
+
+void ConvolutionShader::use(const AffineTransform& transform, const AffineTransform& texTransform, const float* kernel, int kernelWidth, float imageIncrement[2])
+{
+    m_context->useProgram(m_program);
+    float matrix[9];
+    affineTo3x3(transform, matrix);
+    m_context->uniformMatrix3fv(m_matrixLocation, false /*transpose*/, matrix, 1 /*count*/);
+
+    float texMatrix[9];
+    affineTo3x3(texTransform, texMatrix);
+    m_context->uniformMatrix3fv(m_texMatrixLocation, false /*transpose*/, texMatrix, 1 /*count*/);
+
+    m_context->uniform2f(m_imageIncrementLocation, imageIncrement[0], imageIncrement[1]);
+
+    // For now, we always use texture unit 0. If that ever changes, we should
+    // expose this parameter to the caller.
+    m_context->uniform1i(m_imageLocation, 0);
+    if (kernelWidth > m_kernelWidth)
+        kernelWidth = m_kernelWidth;
+    m_context->uniform1fv(m_kernelLocation, const_cast<float*>(kernel), kernelWidth);
+
+    m_context->vertexAttribPointer(m_positionLocation, 3, GraphicsContext3D::FLOAT, false, 0, 0);
+
+    m_context->enableVertexAttribArray(m_positionLocation);
+}
+
+}
+
+#endif