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#include "painter.h"

#include "light.h"

#include "lightmodel.h"

#include "material.h"

FixedFunctionPainter::FixedFunctionPainter()

{

    glEnable(GL_LIGHTING);

    glEnable(GL_LIGHT0);

    glDisable(GL_CULL_FACE);

}

static void setMatrix(GLenum type, const QMatrix4x4 &matrix)

{

    glMatrixMode(type);

    if (sizeof(qreal) == sizeof(GLfloat)) {

        glLoadMatrixf(reinterpret_cast<const GLfloat *>(matrix.constData()));

    } else {

        GLfloat mat[16];

        const qreal *m = matrix.constData();

        for (int index = 0; index < 16; ++index)

            mat[index] = m[index];

        glLoadMatrixf(mat);

    }

}

void FixedFunctionPainter::setMatrices

    (const QMatrix4x4 &mv, const QMatrix4x4 &proj)

{

    setMatrix(GL_PROJECTION, proj);

    setMatrix(GL_MODELVIEW, mv);

}

static void setLight(int light, const Light *parameters,

                     const QMatrix4x4& transform = QMatrix4x4())

{

    GLfloat params[4];

    glMatrixMode(GL_MODELVIEW);

    glPushMatrix();

    glLoadIdentity();

    QColor color = parameters->ambientColor();

    params[0] = color.redF();

    params[1] = color.greenF();

    params[2] = color.blueF();

    params[3] = color.alphaF();

    glLightfv(light, GL_AMBIENT, params);

    color = parameters->diffuseColor();

    params[0] = color.redF();

    params[1] = color.greenF();

    params[2] = color.blueF();

    params[3] = color.alphaF();

    glLightfv(light, GL_DIFFUSE, params);

    color = parameters->specularColor();

    params[0] = color.redF();

    params[1] = color.greenF();

    params[2] = color.blueF();

    params[3] = color.alphaF();

    glLightfv(light, GL_SPECULAR, params);

    QVector4D vector = parameters->eyePosition(transform);

    params[0] = vector.x();

    params[1] = vector.y();

    params[2] = vector.z();

    params[3] = vector.w();

    glLightfv(light, GL_POSITION, params);

    QVector3D spotDirection = parameters->eyeSpotDirection(transform);

    params[0] = spotDirection.x();

    params[1] = spotDirection.y();

    params[2] = spotDirection.z();

    glLightfv(light, GL_SPOT_DIRECTION, params);

    params[0] = parameters->spotExponent();

    glLightfv(light, GL_SPOT_EXPONENT, params);

    params[0] = parameters->spotAngle();

    glLightfv(light, GL_SPOT_CUTOFF, params);

    params[0] = parameters->constantAttenuation();

    glLightfv(light, GL_CONSTANT_ATTENUATION, params);

    params[0] = parameters->linearAttenuation();

    glLightfv(light, GL_LINEAR_ATTENUATION, params);

    params[0] = parameters->quadraticAttenuation();

    glLightfv(light, GL_QUADRATIC_ATTENUATION, params);

    glPopMatrix();

}

static void setLightModel(const LightModel *lightModel)

{

    GLfloat values[4];

#ifdef GL_LIGHT_MODEL_TWO_SIDE

    if (lightModel->model() == LightModel::TwoSided)

        values[0] = 1.0f;

    else

        values[0] = 0.0f;

    glLightModelfv(GL_LIGHT_MODEL_TWO_SIDE, values);

#endif

#ifdef GL_LIGHT_MODEL_COLOR_CONTROL

    if (lightModel->colorControl() == LightModel::SeparateSpecularColor)

        values[0] = GL_SEPARATE_SPECULAR_COLOR;

    else

        values[0] = GL_SINGLE_COLOR;

    glLightModelfv(GL_LIGHT_MODEL_COLOR_CONTROL, values);

#endif

#ifdef GL_LIGHT_MODEL_LOCAL_VIEWER

    if (lightModel->viewerPosition() == LightModel::LocalViewer)

        values[0] = 1.0f;

    else

        values[0] = 0.0f;

    glLightModelfv(GL_LIGHT_MODEL_LOCAL_VIEWER, values);

#endif

#ifdef GL_LIGHT_MODEL_AMBIENT

    QColor color = lightModel->ambientSceneColor();

    values[0] = color.redF();

    values[1] = color.blueF();

    values[2] = color.greenF();

    values[3] = color.alphaF();

    glLightModelfv(GL_LIGHT_MODEL_AMBIENT, values);

#endif

}

static void setMaterial(int face, const Material *parameters)

{

    GLfloat params[17];

    QColor mcolor = parameters->ambientColor();

    params[0] = mcolor.redF();

    params[1] = mcolor.greenF();

    params[2] = mcolor.blueF();

    params[3] = mcolor.alphaF();

    mcolor = parameters->diffuseColor();

    params[4] = mcolor.redF();

    params[5] = mcolor.greenF();

    params[6] = mcolor.blueF();

    params[7] = mcolor.alphaF();

    mcolor = parameters->specularColor();

    params[8] = mcolor.redF();

    params[9] = mcolor.greenF();

    params[10] = mcolor.blueF();

    params[11] = mcolor.alphaF();

    mcolor = parameters->emittedLight();

    params[12] = mcolor.redF();

    params[13] = mcolor.greenF();

    params[14] = mcolor.blueF();

    params[15] = mcolor.alphaF();

    params[16] = parameters->shininess();

    glMaterialfv(face, GL_AMBIENT, params);

    glMaterialfv(face, GL_DIFFUSE, params + 4);

    glMaterialfv(face, GL_SPECULAR, params + 8);

    glMaterialfv(face, GL_EMISSION, params + 12);

    glMaterialfv(face, GL_SHININESS, params + 16);

}

void FixedFunctionPainter::selectMaterial(Material *material)

{

    ::setLight(GL_LIGHT0, light);

    ::setLightModel(lightModel);

    ::setMaterial(GL_FRONT_AND_BACK, material);

    glDisable(GL_TEXTURE_2D);

    glEnableClientState(GL_VERTEX_ARRAY);

    glEnableClientState(GL_NORMAL_ARRAY);

    glDisableClientState(GL_TEXTURE_COORD_ARRAY);

}

void FixedFunctionPainter::selectTexturedMaterial(Material *material)

{

    ::setLight(GL_LIGHT0, light);

    ::setLightModel(lightModel);

    ::setMaterial(GL_FRONT_AND_BACK, material);

    glEnable(GL_TEXTURE_2D);

    glEnableClientState(GL_VERTEX_ARRAY);

    glEnableClientState(GL_NORMAL_ARRAY);

    glEnableClientState(GL_TEXTURE_COORD_ARRAY);

    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);

}

void FixedFunctionPainter::setVertices(const float *array, int stride)

{

    glVertexPointer(3, GL_FLOAT, stride * sizeof(float), array);

}

void FixedFunctionPainter::setTexCoords(const float *array, int stride)

{

    glTexCoordPointer(2, GL_FLOAT, stride * sizeof(float), array);

}

void FixedFunctionPainter::setNormals(const float *array, int stride)

{

    glNormalPointer(GL_FLOAT, stride * sizeof(float), array);

}