commandergenius/src/sdl/COpenGL.cpp

/*
 * COpenGL.cpp
 *
 *  Created on: 04.06.2009
 *      Author: gerstrong
 */
#include "COpenGL.h"
#include "CVideoDriver.h"
#include "../CLogFile.h"

#define GAME_STD_WIDTH            320
#define GAME_STD_HEIGHT           200

COpenGL::COpenGL() {
	m_blitsurface = NULL;
	m_Depth = 4; // 32-bit colour depth
}

COpenGL::~COpenGL() {
	if(m_opengl_buffer){ delete[] m_opengl_buffer; m_opengl_buffer = NULL; }
}

bool COpenGL::initGL(unsigned Width, unsigned Height, unsigned char Depth,
									GLint oglfilter, unsigned char scalex, bool aspect)
{
	m_Depth = Depth;
	m_ScaleX = scalex;
	//m_texparam = GL_TEXTURE_RECTANGLE_ARB;
	m_texparam = GL_TEXTURE_2D;

	// Set the proper resolution for OpenGL. Very important, when user changes the resolution
	if(aspect)
		glViewport(0,(Height-(Height*200)/240)/2,Width, (Height*200)/240);
	else
		glViewport(0,0,Width, Height);
	//glViewport(0,0,1024, 1024);

	// Set clear colour
	glClearColor(0,0,0,0);

	// Set projection
	glMatrixMode( GL_PROJECTION );
	glLoadIdentity();
	glOrtho( 0 , 1, 1, 0 , -1 , 1 );

	// Now Initialize modelview matrix
	glMatrixMode( GL_MODELVIEW );
	glLoadIdentity();

	// Enable Texture loading for the blit screen
	/*  uint textureID;

	  glEnable (GL_TEXTURE_2D);
	  glGenTextures(1, &textureID);
	  glBindTexture(GL_TEXTURE_RECTANGLE_ARB, textureID);
	  //glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
	  glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	  glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
	  glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	  glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
*/

    /*Using the standard OpenGL API for specifying a 2D texture
    image: glTexImage2D, glSubTexImage2D, glCopyTexImage2D,
    and glCopySubTexImage2D.  The target for these commands is
    GL_TEXTURE_RECTANGLE_ARB though.

    This is similar to how the texture cube map functionality uses the 2D
    texture image specification API though with its own texture target.

    The texture target GL_TEXTURE_RECTANGLE_ARB should also
    be used for glGetTexImage, glGetTexLevelParameteriv, and
    glGetTexLevelParameterfv.*/


	glEnable (m_texparam);
	glBindTexture(m_texparam, 1);
	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

	glTexParameteri(m_texparam, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri (m_texparam, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);


	glTexParameteri (m_texparam, GL_TEXTURE_MAG_FILTER, oglfilter);
	glTexParameteri (m_texparam, GL_TEXTURE_MIN_FILTER, oglfilter);

	glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);


	if(scalex > 1)
		m_opengl_buffer = new char[GAME_STD_HEIGHT*GAME_STD_WIDTH*scalex*Depth];
	else
		m_opengl_buffer = NULL;

	// If there were any errors
	int error;
	error = glGetError();
	if( error != GL_NO_ERROR)
	{
		g_pLogFile->ftextOut("OpenGL Init(): %d<br>",error);
		return false;
	}
	else
	{
		g_pLogFile->ftextOut("OpenGL Init(): Interface succesfully opened!<br>");
	}

	return true;
}

void COpenGL::setSurface(SDL_Surface *blitsurface)
{	m_blitsurface = blitsurface; }

void COpenGL::render(void)
{
	   //Clear the screen
	   glClear(GL_COLOR_BUFFER_BIT);		// Clear The Screen

	   LockSurface(m_blitsurface);

	   if(m_ScaleX == 2) //Scale 2x
	   {
		   scale(2, m_opengl_buffer, (GAME_STD_WIDTH<<1)*(m_Depth>>3), m_blitsurface->pixels,
			     GAME_STD_WIDTH*(m_Depth>>3), (m_Depth>>3), GAME_STD_WIDTH, GAME_STD_HEIGHT);

		   glTexImage2D(m_texparam, 0, GL_RGBA, GAME_STD_WIDTH<<1, GAME_STD_HEIGHT<<1, 0, GL_BGRA, GL_UNSIGNED_BYTE, m_opengl_buffer);
		   //glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA, GAME_STD_WIDTH<<1, GAME_STD_HEIGHT<<1, 0, GL_BGRA, GL_UNSIGNED_BYTE, m_opengl_buffer);
		   //glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA8, GAME_STD_WIDTH<<1, GAME_STD_HEIGHT<<1, 0, GL_BGRA, GL_UNSIGNED_BYTE, m_opengl_buffer);
	   }
	   else if(m_ScaleX == 3) //Scale 3x
	   {
		   scale(3, m_opengl_buffer, (GAME_STD_WIDTH*3)*(m_Depth>>3), m_blitsurface->pixels,
				   GAME_STD_WIDTH*(m_Depth>>3), (m_Depth>>3), GAME_STD_WIDTH, GAME_STD_HEIGHT);

		   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, GAME_STD_WIDTH*3, GAME_STD_HEIGHT*3, 0, GL_BGRA, GL_UNSIGNED_BYTE, m_opengl_buffer);
	   }
	   else if(m_ScaleX == 4) //Scale 4x
	   {
		   scale(4, m_opengl_buffer, (GAME_STD_WIDTH<<2)*(m_Depth>>3), m_blitsurface->pixels,
				   GAME_STD_WIDTH*(m_Depth>>3), (m_Depth>>3), GAME_STD_WIDTH, GAME_STD_HEIGHT);

		   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, GAME_STD_WIDTH<<2, GAME_STD_HEIGHT<<2, 0, GL_BGRA, GL_UNSIGNED_BYTE, m_opengl_buffer);
	   }
	   else
		   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, GAME_STD_WIDTH, GAME_STD_HEIGHT, 0, GL_BGRA, GL_UNSIGNED_BYTE, m_blitsurface->pixels);


	   glBindTexture (GL_TEXTURE_2D, 1);

	   glBegin (GL_QUADS);
		   glTexCoord2f (0.0, 0.0);
		   glVertex3f (0.0, 0.0, 0.0);
		   glTexCoord2f (1.0, 0.0);
		   glVertex3f (1.0, 0.0, 0.0);
		   glTexCoord2f (1.0, 1.0);
		   glVertex3f (1.0, 1.0, 0.0);
		   glTexCoord2f (0.0, 1.0);
		   glVertex3f (0.0, 1.0, 0.0);
	   glEnd();

	   UnlockSurface(m_blitsurface);

	   // Reset (Position?)
	   glLoadIdentity();

	   SDL_GL_SwapBuffers();
}