Dengine/src/Texture.cpp

#include <Dengine\Texture.h>

namespace Dengine
{
Texture::Texture()
: mId(0)
, mWidth(0)
, mHeight(0)
, mInternalFormat(GL_RGB)
, mImageFormat(GL_RGB)
, mWrapS(GL_REPEAT)
, mWrapT(GL_REPEAT)
, mFilterMinification(GL_LINEAR)
, mFilterMagnification(GL_LINEAR)
{
	glGenTextures(1, &mId);
}

enum BytesPerPixel
{
	Greyscale      = 1,
	GreyscaleAlpha = 2,
	RGB            = 3,
	RGBA           = 4,
};

INTERNAL GLint getGLFormat(BytesPerPixel bytesPerPixel, b32 srgb)
{
	switch (bytesPerPixel)
	{
		case Greyscale:
			return GL_LUMINANCE;
		case GreyscaleAlpha:
			return GL_LUMINANCE_ALPHA;
		case RGB:
			return (srgb ? GL_SRGB : GL_RGB);
		case RGBA:
			return (srgb ? GL_SRGB_ALPHA : GL_RGBA);
		default:
			// TODO(doyle): Invalid
		    //std::cout << "getGLFormat() invalid bytesPerPixel: "
		    //          << bytesPerPixel << std::endl;
		    return GL_LUMINANCE;
	}
}

void Texture::generate(GLuint width, GLuint height, u8 *image)
{
	// TODO(doyle): Let us set the parameters gl params as well 
	mWidth  = width;
	mHeight = height;

	glBindTexture(GL_TEXTURE_2D, mId);

	/* Load image into texture */
	// TODO(doyle) Figure out the gl format
	glTexImage2D(GL_TEXTURE_2D, 0, mInternalFormat, mWidth, mHeight, 0,
	             mImageFormat, GL_UNSIGNED_BYTE, image);
	glGenerateMipmap(GL_TEXTURE_2D);

	/* Set parameter of currently bound texture */
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, mWrapS);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, mWrapT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, mFilterMinification);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, mFilterMagnification);

	/* Unbind and clean up */
	glBindTexture(GL_TEXTURE_2D, 0);
}

void Texture::bind() const { glBindTexture(GL_TEXTURE_2D, mId); }
}