#include "texture.h"
#include "config.h"

#include <stdio.h>

#include <GL/gl.h>
#include <tqimage.h>
#include <tqgl.h>
#include <tdeglobal.h>
#include <tdeconfig.h>
#include <tqstring.h>
#include <kstandarddirs.h>

KueTexture::KueTexture(const TQString &filename)
{
	_filename = filename;
	_texture_id = 0;

	if (filename.isNull())
	{
		// filename == TQString::null is an alias for the null texture
		_loaded = true;
	}
	else
	{
		_loaded = false;
	}
}

KueTexture::KueTexture(unsigned int texture_id)
{
	_filename = TQString::null;
	_texture_id = texture_id;
	_loaded = true;
}

KueTexture::KueTexture(const KueTexture &t)
{
	// Is the texture file backed?
	if (t._filename.isNull())
	{
		// This is easy, copy over the texture id
		_texture_id = t._texture_id;
		_loaded = true;
	}
	else
	{
		// Yes, copy over the filename
		_filename = t._filename;
		_loaded = false;
	}
}

KueTexture KueTexture::null() {
	return KueTexture(0);
}

KueTexture::~KueTexture()
{
	// We only "own" the texture ID if we were created from a filename
	// Also check that we've allocated a valid texture ID. That means
	// that the texture is loaded, and it's non-NULL.
	// We don't use isNull(), because that forces a file load
	if (_loaded && _texture_id && (!_filename.isNull()))
	{
		// Free a texture ID and its associated texture
		glDeleteTextures(1, &_texture_id);
	}
}

bool KueTexture::isNull()
{
	load();

	return (_texture_id == 0);
}

void KueTexture::load()
{
	if (_loaded)
	{
		// The texture is already loaded, nothing to do here
		return;
	}

	//  Get the full pathname for the texture
	TQImage raw_image, gl_image;
	TQString fullname;

	// Find the real filename
	fullname = TDEGlobal::dirs()->findResource("appdata", "textures/" + _filename + ".png");

	// Try to load the file
	if (raw_image.load(fullname)) 
	{
		gl_image = TQGLWidget::convertToGLFormat(raw_image);   

		// Ask OpenGL for a new texture ID
		glGenTextures(1, &_texture_id);

		// Make it the current texture (blank right now)
		glBindTexture(GL_TEXTURE_2D, _texture_id);

		// Should we filter textures?
		TDEGlobal::config()->setGroup("Graphics");
		if (TDEGlobal::config()->readBoolEntry("Filter Textures", false))
		{
			// Yes, enable smooth scaling
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
		}
		else
		{
			// No, enable fast scaling
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
		}

		// Load the image data in to the texture
		glTexImage2D(GL_TEXTURE_2D, 0, 3, gl_image.width(), gl_image.height(), 0,
		             GL_RGBA, GL_UNSIGNED_BYTE, gl_image.bits());
	}
	else
	{
		// Unable to load image, use null texture
		_texture_id = 0;
	}

	_loaded = true;
}

bool KueTexture::makeCurrent()
{
	load();

	// Sets the current 2D texture, where 0 means no texture
	glBindTexture(GL_TEXTURE_2D, _texture_id);

	return true;
}