#include "texture.h"
#include "glassert.h"
#include <QImage>

Texture::Texture(const QString filename) : type(GL_TEXTURE_2D)
{
    glAssert(glGenTextures(1, &texId));
    glAssert(glBindTexture(type, texId));

    createTexture(filename, GL_TEXTURE_2D);
    setWrap(GL_REPEAT);
    setFiltering(GL_NEAREST);
}

Texture::Texture(const QString filename[6]) : type(GL_TEXTURE_CUBE_MAP)
{
    glAssert(glActiveTexture(GL_TEXTURE0));
    glAssert(glGenTextures(1, &texId));
    glAssert(glBindTexture(type, texId));

    for(int i=0; i<6; ++i)
    {
        createTexture(filename[i], GL_TEXTURE_CUBE_MAP_POSITIVE_X + i);
        setWrap(GL_CLAMP_TO_EDGE);
        setFiltering(GL_LINEAR);
    }
}

Texture::~Texture()
{
    glAssert(glDeleteTextures(1, &texId));
}

void Texture::createTexture(QString filename, GLenum textureSlot)
{
    QImage img(filename);
    int bpp = (img.depth() == 32) ? GL_RGBA : GL_RGB;
    int format = (img.depth() == 32) ? GL_BGRA : GL_BGR;
    glAssert(glTexImage2D(textureSlot, 0, bpp, img.width(), img.height(), 0, format, GL_UNSIGNED_BYTE, img.bits()));
}

void Texture::setWrap(GLint wrap)
{
    glAssert(glTexParameteri(type, GL_TEXTURE_WRAP_S, wrap));
    glAssert(glTexParameteri(type, GL_TEXTURE_WRAP_T, wrap));
    glAssert(glTexParameteri(type, GL_TEXTURE_WRAP_R, wrap));
}

void Texture::setFiltering(GLint filter)
{
    glAssert(glTexParameteri(type, GL_TEXTURE_MIN_FILTER, filter));
    glAssert(glTexParameteri(type, GL_TEXTURE_MAG_FILTER, filter));
}

void Texture::bind(int slot)
{
    GLenum texSlot = GL_TEXTURE0+slot;
    glAssert(glActiveTexture(texSlot));
    glAssert(glBindTexture(type, texId));
}