painter_shader.cpp Example File

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 #include "painter.h"
 #include "light.h"
 #include "lightmodel.h"
 #include "material.h"
 #include <QtOpenGL/qglshaderprogram.h>

 ShaderPainter::ShaderPainter()
 {
     materialProgram = new QGLShaderProgram();
     materialProgram->addShaderFromSourceFile
         (QGLShader::Vertex, QLatin1String(":/lighting.vsh"));
     materialProgram->addShaderFromSourceFile
         (QGLShader::Fragment, QLatin1String(":/material.fsh"));
     materialProgram->bindAttributeLocation("vertex", 0);
     materialProgram->bindAttributeLocation("normal", 1);
     materialProgram->bindAttributeLocation("texcoord", 2);
     materialProgram->link();

     textureProgram = new QGLShaderProgram();
     textureProgram->addShaderFromSourceFile
         (QGLShader::Vertex, QLatin1String(":/lighting.vsh"));
     textureProgram->addShaderFromSourceFile
         (QGLShader::Fragment, QLatin1String(":/texture.fsh"));
     textureProgram->bindAttributeLocation("vertex", 0);
     textureProgram->bindAttributeLocation("normal", 1);
     textureProgram->bindAttributeLocation("texcoord", 2);
     textureProgram->link();

     currentProgram = 0;
     matricesChanged = false;
 }

 ShaderPainter::~ShaderPainter()
 {
     delete materialProgram;
     delete textureProgram;
 }

 void ShaderPainter::setMatrices(const QMatrix4x4 &mv, const QMatrix4x4 &proj)
 {
     combinedMatrix = proj * mv;
     modelViewMatrix = mv;
     normalMatrix = mv.normalMatrix();
     matricesChanged = true;
 }

 void ShaderPainter::selectMaterial(Material *material)
 {
     if (currentProgram != materialProgram) {
         materialProgram->bind();
         materialProgram->enableAttributeArray(0);
         materialProgram->enableAttributeArray(1);
         materialProgram->disableAttributeArray(2);
         currentProgram = materialProgram;
         matricesChanged = true;
     }
     if (matricesChanged) {
         materialProgram->setUniformValue("matrix", combinedMatrix);
         materialProgram->setUniformValue("modelView", modelViewMatrix);
         materialProgram->setUniformValue("normalMatrix", normalMatrix);
         matricesChanged = false;
     }
     updateMaterials(materialProgram, material);
 }

 void ShaderPainter::selectTexturedMaterial(Material *material)
 {
     if (currentProgram != textureProgram) {
         textureProgram->bind();
         textureProgram->enableAttributeArray(0);
         textureProgram->enableAttributeArray(1);
         textureProgram->enableAttributeArray(2);
         textureProgram->setUniformValue("tex", 0);
         currentProgram = textureProgram;
         matricesChanged = true;
     }
     if (matricesChanged) {
         textureProgram->setUniformValue("matrix", combinedMatrix);
         textureProgram->setUniformValue("modelView", modelViewMatrix);
         textureProgram->setUniformValue("normalMatrix", normalMatrix);
         matricesChanged = false;
     }
     updateMaterials(textureProgram, material);
 }

 void ShaderPainter::setVertices(const float *array, int stride)
 {
     // Doesn't matter which program we use - they have the same locations.
     materialProgram->setAttributeArray(0, array, 3, stride * sizeof(float));
 }

 void ShaderPainter::setTexCoords(const float *array, int stride)
 {
     materialProgram->setAttributeArray(2, array, 2, stride * sizeof(float));
 }

 void ShaderPainter::setNormals(const float *array, int stride)
 {
     materialProgram->setAttributeArray(1, array, 3, stride * sizeof(float));
 }

 void ShaderPainter::updateMaterials
     (QGLShaderProgram *program, Material *material)
 {
     // Set the uniform variables for the light.
     QVector4D pli = light->eyePosition(QMatrix4x4());
     program->setUniformValue("pli", QVector3D(pli.x(), pli.y(), pli.z()));
     program->setUniformValue("pliw", GLfloat(pli.w()));

     // Set the uniform variables for the light model.
     program->setUniformValue("viewerAtInfinity", (int)(lightModel->viewerPosition() == LightModel::ViewerAtInfinity));
     program->setUniformValue("acs", lightModel->ambientSceneColor());

     // Set the uniform variables for the material.
     program->setUniformValue("acm", material->ambientColor());
     program->setUniformValue("dcm", material->diffuseColor());
     program->setUniformValue("scm", material->specularColor());
     program->setUniformValue("srm", (float)(material->shininess()));
 }