gl: add ConvolutionShader for convenience

bug: shader program does not update if setKernelRadius

src/QtAV/ConvolutionShader.h

@@ -0,0 +1,60 @@
+/******************************************************************************
+    QtAV:  Multimedia framework based on Qt and FFmpeg
+    Copyright (C) 2012-2016 Wang Bin <[email protected]>
+
+*   This file is part of QtAV (from 2016)
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+******************************************************************************/
+#ifndef QTAV_CONVOLUTIONSHADER_H
+#define QTAV_CONVOLUTIONSHADER_H
+#include <QtAV/VideoShader.h>
+
+namespace QtAV {
+class ConvolutionShaderPrivate;
+/*!
+ * \brief The ConvolutionShader class
+ * Uniform u_Kernel is used
+ */
+class Q_AV_EXPORT ConvolutionShader : public VideoShader
+{
+    DPTR_DECLARE_PRIVATE(ConvolutionShader)
+public:
+    ConvolutionShader();
+    /*!
+     * \brief kernelRadius
+     * Default is 1, i.e. 3x3 kernel
+     * kernelSize is (2*kernelRadius()+1)^2
+     * \return
+     */
+    int kernelRadius() const;
+    /// TODO: update shader program if radius is changed. mark dirty program
+    void setKernelRadius(int value);
+    int kernelSize() const;
+
+    /// default implementions
+    const char* userShaderHeader(QOpenGLShader::ShaderType t) const Q_DECL_OVERRIDE;
+    const char* userSample() const Q_DECL_OVERRIDE;
+    void setUserUniformValues() Q_DECL_OVERRIDE;
+
+protected:
+    virtual const float* kernel() const = 0;
+    const QByteArray& kernelUniformHeader() const; //can be used in your userFragmentShaderHeader();
+    const QByteArray& kernelSample() const; //can be  in your userSample();
+    void setKernelUniformValue(); // can be used in your setUserUniformValues()
+    ConvolutionShader(ConvolutionShaderPrivate &d);
+};
+} //namespace QtAV
+#endif // QTAV_CONVOLUTIONSHADER_H

src/QtAV/QtAV.h

@@ -1,5 +1,5 @@
 /******************************************************************************
-    QtAV:  Media play library based on Qt and FFmpeg
+    QtAV:  Multimedia framework based on Qt and FFmpeg
     Copyright (C) 2012-2016 Wang Bin <[email protected]>
 
 *   This file is part of QtAV
@@ -48,6 +48,7 @@
 
 #include <QtAV/VideoShader.h>
 #include <QtAV/OpenGLVideo.h>
+#include <QtAV/ConvolutionShader.h>
 
 #include <QtAV/VideoCapture.h>
 #include <QtAV/VideoEncoder.h>

src/libQtAV.pro

@@ -313,6 +313,7 @@ config_gl|config_opengl {
   SDK_HEADERS *= \
     QtAV/OpenGLRendererBase.h \
     QtAV/OpenGLVideo.h \
+    QtAV/ConvolutionShader.h \
     QtAV/VideoShader.h
   SDK_PRIVATE_HEADERS = \
     QtAV/private/OpenGLRendererBase_p.h
@@ -324,6 +325,7 @@ config_gl|config_opengl {
     OpenGLVideo.cpp \
     VideoShader.cpp \
     ShaderManager.cpp \
+    opengl/ConvolutionShader.cpp \
     utils/OpenGLHelper.cpp
 }
 config_openglwindow {

src/opengl/ConvolutionShader.cpp

@@ -0,0 +1,124 @@
+/******************************************************************************
+    QtAV:  Multimedia framework based on Qt and FFmpeg
+    Copyright (C) 2012-2016 Wang Bin <[email protected]>
+
+*   This file is part of QtAV (from 2016)
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+******************************************************************************/
+#include "QtAV/ConvolutionShader.h"
+#include "QtAV/private/VideoShader_p.h"
+
+namespace QtAV {
+class ConvolutionShaderPrivate : public VideoShaderPrivate
+{
+public:
+    ConvolutionShaderPrivate() : VideoShaderPrivate()
+      , u_Kernel(-1)
+      , radius(1)
+    {
+        kernel.resize((2*radius+1)*(2*radius+1));
+        updateShaderCode();
+    }
+    void updateShaderCode() {
+        const int ks = (2*radius+1)*(2*radius+1);
+        header = QByteArray("uniform float u_Kernel[")
+                .append(QByteArray::number(ks))
+                .append("];");
+        QByteArray s("vec4 sample2d(sampler2D tex, vec2 pos, int p) { vec4 c = vec4(0.0);");
+        const int kd = 2*radius+1;
+        for (int i = 0; i < ks; ++i) {
+            const int x = i % kd - radius;
+            const int y = i / kd - radius;
+            s += "c += texture(tex, pos + u_texelSize[p]*vec2(";
+            s += QByteArray::number((float)x, 'f', 1);
+            s += ",";
+            s += QByteArray::number((float)y, 'f', 1);
+            s += "))*u_Kernel[";
+            s += QByteArray::number(i);
+            s += "];\n";
+        }
+        s += "c.a = texture(tex, pos).a;"
+             "return c;}\n";
+        sample_func = s;
+    }
+
+    int u_Kernel;
+    int radius;
+    QVector<float> kernel;
+    QByteArray header, sample_func;
+};
+
+ConvolutionShader::ConvolutionShader()
+    : VideoShader(*new ConvolutionShaderPrivate())
+{}
+
+ConvolutionShader::ConvolutionShader(ConvolutionShaderPrivate &d)
+    : VideoShader(d)
+{}
+
+int ConvolutionShader::kernelRadius() const
+{
+    return d_func().radius;
+}
+
+void ConvolutionShader::setKernelRadius(int value)
+{
+    DPTR_D(ConvolutionShader);
+    if (d.radius == value)
+        return;
+    d.radius = value;
+    d.kernel.resize(kernelSize());
+    d.updateShaderCode();
+}
+
+int ConvolutionShader::kernelSize() const
+{
+    return (2*kernelRadius() + 1)*(2*kernelRadius() + 1);
+}
+
+const char* ConvolutionShader::userShaderHeader(QOpenGLShader::ShaderType t) const
+{
+    if (t == QOpenGLShader::Vertex)
+        return 0;
+    return kernelUniformHeader().constData();
+}
+
+const char* ConvolutionShader::userSample() const
+{
+    return kernelSample().constData();
+}
+
+void ConvolutionShader::setUserUniformValues()
+{
+    setKernelUniformValue();
+}
+
+const QByteArray& ConvolutionShader::kernelUniformHeader() const
+{
+    return d_func().header;
+}
+
+const QByteArray& ConvolutionShader::kernelSample() const
+{
+    return d_func().sample_func;
+}
+
+void ConvolutionShader::setKernelUniformValue()
+{
+    program()->setUniformValueArray("u_Kernel", kernel(), kernelSize(), 1);
+}
+
+} //namespace QtAV