/* libsegl - Sebas Extended GL Library
 *           Collection of Opengl/3D-Math helpers
 *
 *      Copyright (c) 2008 by Sebastian Lohff, seba@seba-geek.de
 *      http://www.seba-geek.de
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA  02110-1301, USA.
 */

#include "glsdlscreen.h"

namespace segl {

GLSDLScreen::GLSDLScreen() {
	width = 0;
	height = 1;
	bpp = 16;
	znear = 1.0f;
	zfar = 100.0f;
	
	opengl = false;
	glsetup = true;
	resizable = false;
	fullscreen = false;
	
	extraglparam = 0;
}


int GLSDLScreen::getFlags() {
	const SDL_VideoInfo *videoInfo = SDL_GetVideoInfo();
	int videoflags = 0;
	if(videoInfo->hw_available)
		videoflags |= SDL_HWSURFACE;
	else
		videoflags |= SDL_SWSURFACE;
	if(videoInfo->blit_hw)
		videoflags |= SDL_HWACCEL;
	
	if(opengl) {
		videoflags |= SDL_OPENGL;
		videoflags |= SDL_GL_DOUBLEBUFFER;
		videoflags |= SDL_HWPALETTE;
	}
	
	if(fullscreen)
		videoflags |= SDL_FULLSCREEN;
	
	return videoflags;
}
void GLSDLScreen::enableOpenGL(bool w) {
	opengl = w;
}

void GLSDLScreen::enableResizable(bool w) {
	resizable = w;
}

void GLSDLScreen::enableFullscreen(bool w) {
	fullscreen = w;
}

void GLSDLScreen::setGLNearFar(float _znear, float _zfar) {
	znear = _znear;
	zfar  = _zfar;
}

void GLSDLScreen::enableGLSetup(bool w) {
	glsetup = w;
}

void GLSDLScreen::setExtraGLParamFunc(void (*extrafunc)()) {
	extraglparam = extrafunc;
}

void GLSDLScreen::setVideoMode(int _width, int _height, int _bpp) {
	width = _width;
	height = _height;
	bpp = _bpp;
	
	if(height==0)
		height = 1;
}

void GLSDLScreen::getVideoRes(std::string vidstr, int *_w, int *_h) {
	if(_w)
		*_w = atoi(vidstr.substr(0, vidstr.find("x")).c_str());
	if(_h)
		*_h = atoi(vidstr.substr(vidstr.find("x")+1, (vidstr.length()-vidstr.find("x")-1)).c_str());
}

bool GLSDLScreen::isOK() {
	return SDL_VideoModeOK(width, height, bpp, getFlags());
}

bool GLSDLScreen::apply() {
	if(!SDL_WasInit(SDL_INIT_VIDEO)) {
		if(SDL_Init(SDL_INIT_VIDEO)==-1) {
			std::cerr << "Konnte SDL_VIDEO nicht initialisieren" << std::endl;
			return false;
		}
	}
	
	screen = SDL_SetVideoMode(width, height, bpp, getFlags());
	
	if(!screen) {
		return false;
	}
	
	if(opengl) {
		SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
			
		
		// Setup GL
		if(glsetup) {
			glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
			glClearDepth(1.0f);
			glDepthFunc(GL_LEQUAL);
			glShadeModel(GL_SMOOTH);
			glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
			glEnable(GL_ALPHA_TEST);
			glAlphaFunc(GL_GREATER, 0.1);
			glEnable(GL_DEPTH_TEST);
		}
		
		// Projection
		glViewport(0, 0, (GLsizei)width, (GLsizei)height);
		
		glMatrixMode(GL_PROJECTION);
		glLoadIdentity();
		gluPerspective(45.0f, (GLfloat)width/(GLfloat)height, znear, zfar);
		
		if(extraglparam) {
			extraglparam();
		}
		
		

		// Texturen neuladen, eigentlich nur f�r Windows. Aber egal.
		GLTexture::reloadAll();
		glMatrixMode(GL_TEXTURE);
		glLoadIdentity();
		
		glMatrixMode(GL_MODELVIEW);
	}
	
	return true;
}

int GLSDLScreen::getWidth() {
	return width;
}

int GLSDLScreen::getHeight() {
	return height;
}

void GLSDLScreen::clearScreen() {
	glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glLoadIdentity();
}

void GLSDLScreen::renderScreen() {
	SDL_GL_SwapBuffers();
}

} // namespace segl