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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()));

}