/* ScummVM - Scumm Interpreter
 * Copyright (C) 2001  Ludvig Strigeus
 * Copyright (C) 2001-2003 The ScummVM project
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program 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 General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header: /cvsroot/scummvm/scummvm/backends/sdl/sdl_gl.cpp,v 1.53 2003/09/06 20:21:54 fingolfin Exp $
 *
 */

#include "sdl-common.h"
#include "common/scaler.h"
#include "common/util.h"
#include "common/engine.h"	// Only #included for error() and warning()

#ifdef WIN32
int glColorTable(int, int, int, int, int, void *) { return 0; }
int glGetColorTable(int, int, int, void *) { return 0; }
#endif

#include "fb2opengl.h"

class OSystem_SDL_OpenGL : public OSystem_SDL_Common {
public:
	OSystem_SDL_OpenGL();

	// Update the dirty areas of the screen
	void update_screen();

	// Set a parameter
	uint32 property(int param, Property *value);

	// Get the next event.
	// Returns true if an event was retrieved.	
	//bool poll_event(Event *event);

protected:
	FB2GL fb2gl;
	int _glFlags;
	int _glScreenStart;
	bool _glBilinearFilter;
	bool _usingOpenGL;
	SDL_Surface *tmpSurface; // Used for black rectangles blitting 
	SDL_Rect tmpBlackRect;   // Bottom black border
	SDL_Rect _glWindow;      // Only uses w and h (for window resizing)
	int _glBottomOfTexture;
	int _glBorderHeight;     // Used if using black borders

	SDL_Surface *_hwscreen;  // hardware screen (=> _usingOpenGL == false)

	ScalerProc *_scaler_proc;
	
	virtual void load_gfx_mode();
	virtual void unload_gfx_mode();
	virtual bool save_screenshot(const char *filename);
	void hotswap_gfx_mode();
};

OSystem_SDL_Common *OSystem_SDL_Common::create_intern() {
	return new OSystem_SDL_OpenGL();
}

OSystem_SDL_OpenGL::OSystem_SDL_OpenGL()
  : _hwscreen(0), _scaler_proc(0)
{
  _glScreenStart = 0; 
  _glBilinearFilter = false;
  _usingOpenGL = false; // false => Switch to filters used in the sdl.cpp version
  _glBottomOfTexture = 256; // height is always 256
  _glBorderHeight = 0; // Forces _glScreenStart to always be 0
  // 640x480 resolution
  _glWindow.w = 640;
  _glWindow.h = 480;
}

void OSystem_SDL_OpenGL::load_gfx_mode() {
	uint32 Rmask, Gmask, Bmask, Amask;
	// I have to force 16 bit color depth with 565 ordering
	// SDL_SetVideoMode sometimes doesn't accept your color depth definition
	Rmask = 0xF800; // 5
	Gmask = 0x07E0; // 6
	Bmask = 0x001F; // 5
	Amask = 0;

	_forceFull = true;
	_mode_flags |= DF_UPDATE_EXPAND_1_PIXEL;

	_tmpscreen = NULL;
	_tmpScreenWidth = (_screenWidth + 3);

	switch(_mode) {
	case GFX_BILINEAR:
		_usingOpenGL = true;
		_mode = GFX_NORMAL;
		break;
	case GFX_2XSAI:
		_scaleFactor = 2;
		_scaler_proc = _2xSaI;
		break;
	case GFX_SUPER2XSAI:
		_scaleFactor = 2;
		_scaler_proc = Super2xSaI;
		break;
	case GFX_SUPEREAGLE:
		_scaleFactor = 2;
		_scaler_proc = SuperEagle;
		break;
	case GFX_ADVMAME2X:
		_scaleFactor = 2;
		_scaler_proc = AdvMame2x;
		break;
	case GFX_ADVMAME3X:
		_scaleFactor = 3;
		_scaler_proc = AdvMame3x;
		break;
	case GFX_TV2X:
		_scaleFactor = 2;
		_scaler_proc = TV2x;
		break;
	case GFX_DOTMATRIX:
		_scaleFactor = 2;
		_scaler_proc = DotMatrix;
		break;
	case GFX_DOUBLESIZE:
		_scaleFactor = 2;
		_scaler_proc = Normal2x;
		break;

	case GFX_TRIPLESIZE:
		_scaleFactor = 3;
		_scaler_proc = Normal3x;
		break;

	case GFX_NORMAL:
		_scaleFactor = 1; //_usingOpenGL ? 2 : 1;
		_scaler_proc = Normal1x;
		break;
	default:
		error("unknown gfx mode %d", _mode);
		_mode = GFX_NORMAL;
		_scaleFactor = 1;
		_scaler_proc = Normal1x;
	}

	if (_mode != GFX_NORMAL) {
	  _usingOpenGL = false;
	}
  
	//
	// Create the surface that contains the 8 bit game data
	//
	_screen = SDL_CreateRGBSurface(SDL_SWSURFACE, _screenWidth, _screenHeight, 8, 0, 0, 0, 0);
	if (_screen == NULL)
		error("_screen failed");

	//
	// Create the surface that contains the scaled graphics in 16 bit mode
	//
	if (_usingOpenGL) {
	  
		_glFlags = FB2GL_NO_320 | FB2GL_RGBA | FB2GL_16BIT;
		if (_full_screen) {
			_glFlags |= FB2GL_FS;
			_glScreenStart = 0;
		}
		
		// Note: Our GL screen is vertically stretched (yfix = 15).
		// That makes visible only 320x240 of the GL screen.
		// 320x240 visible in GL screen => yfix = 15
		// 320x200 visible in GL screen => yfix = 72
		int yfix = 15;
		_glBorderHeight = 0;
		if (_screenHeight == 200) {
		    // If we are not using borders, we want 320x200 visible
		    yfix = _glScreenStart? 15: 72;
		    // 20 (top) + 200 (height) + 20 (bottom) = 240
		    _glBorderHeight = 20;
		}
		// _glWindow defines the resolution
		fb2gl.init(_glWindow.w, _glWindow.h, 0, yfix, _glFlags);
		
	} else { // SDL backend
	  
		_hwscreen = SDL_SetVideoMode(_screenWidth * _scaleFactor, (_adjustAspectRatio ? 240 : _screenHeight) * _scaleFactor, 16, 
		_full_screen ? (SDL_FULLSCREEN|SDL_SWSURFACE) : SDL_SWSURFACE
		);
		if (_hwscreen == NULL)
			error("_hwscreen failed");

		// Distinguish 555 and 565 mode
		if (_hwscreen->format->Rmask == 0x7C00)
			Init_2xSaI(555);
		else
			Init_2xSaI(565);
	}

	//
	// Create the surface used for the graphics in 16 bit before scaling, and also the overlay
	//

	// Need some extra bytes around when using 2xSaI
	uint16 *tmp_screen = (uint16 *)calloc(_tmpScreenWidth * (_screenHeight + 3),sizeof(uint16));

	if (_usingOpenGL) {
		_tmpscreen = SDL_CreateRGBSurfaceFrom(tmp_screen,
						_tmpScreenWidth, 
						_screenHeight + 3, 
						16, 
						_tmpScreenWidth * 2,
						Rmask,
						Gmask,
						Bmask,
						Amask);

		tmpBlackRect.x = 0;
		tmpBlackRect.y = 0;
		tmpBlackRect.w = _screenWidth;
		tmpBlackRect.h = 256-_screenHeight-_glScreenStart;

		if (!_adjustAspectRatio) {
			// Don't use the whole screen (black borders)
			fb2gl.init(0, 0, 0, 15, _glFlags);
			_glScreenStart = _glBorderHeight;

			// Top black border
			SDL_Rect blackrect = {
			  0, 
			  0, // _glScreenStart, 
			  _screenWidth, 
			  _newShakePos + _glScreenStart
			};
	
			SDL_FillRect(tmpSurface, &blackrect, 0);
			fb2gl.blit16(tmpSurface, 1, &blackrect, 0, 0);
		
			// Bottom black border
			int _glBottomOfGameScreen = _screenHeight + 
			  _glScreenStart + _currentShakePos; 

			tmpBlackRect.h = _glBottomOfTexture - 
			  _glBottomOfGameScreen;
			
			SDL_FillRect(tmpSurface, &tmpBlackRect, 0);
			fb2gl.blit16(tmpSurface, 1, &tmpBlackRect, 0,
			  _glBottomOfGameScreen);
		} else {
			// Use the whole screen
			fb2gl.init(0, 0, 0, 72, _glFlags);
			_glScreenStart = 0;
		}

	} else { // SDL backend
		_tmpscreen = SDL_CreateRGBSurfaceFrom(tmp_screen,
						_tmpScreenWidth, 
						_screenHeight + 3, 
						16, 
						_tmpScreenWidth * 2,
						_hwscreen->format->Rmask,
						_hwscreen->format->Gmask,
						_hwscreen->format->Bmask,
						_hwscreen->format->Amask);
	}

	tmpSurface = SDL_CreateRGBSurface(SDL_SWSURFACE, _screenWidth, 
						// 320x256 texture (black end)
						256-_screenHeight-_glScreenStart,
						16,
						Rmask,
						Gmask,
						Bmask,
						Amask);
	
	if (_tmpscreen == NULL)
		error("_tmpscreen failed");

	// keyboard cursor control, some other better place for it?
	km.x_max = _screenWidth * _scaleFactor - 1;
	km.y_max = _screenHeight * _scaleFactor - 1;
	km.delay_time = 25;
	km.last_time = 0;
}

void OSystem_SDL_OpenGL::unload_gfx_mode() {
  
	if (_screen) {
		SDL_FreeSurface(_screen);
		_screen = NULL; 
	}
	if (_hwscreen) {
		SDL_FreeSurface(_hwscreen);
		_hwscreen = NULL; 
	}
	if (_tmpscreen) {
		free((uint16 *)_tmpscreen->pixels);
		SDL_FreeSurface(_tmpscreen);
		_tmpscreen = NULL;
	}
}

void OSystem_SDL_OpenGL::hotswap_gfx_mode() {
	if (!_screen)
		return;

	// Keep around the old _screen & _tmpscreen so we can restore the screen data
	// after the mode switch.
	SDL_Surface *old_screen = _screen;
	SDL_Surface *old_tmpscreen = _tmpscreen;

	// Release the HW screen surface
	if (fb2gl.getScreen()) { // _usingOpenGL was true
		SDL_FreeSurface(fb2gl.getScreen());
		fb2gl.setScreen(NULL);
	}
	if (_hwscreen) {
		SDL_FreeSurface(_hwscreen);
		_hwscreen = NULL;
	}

	// Setup the new GFX mode
	load_gfx_mode();

	// reset palette
	SDL_SetColors(_screen, _currentPalette, 0, 256);

	// Restore old screen content
	SDL_BlitSurface(old_screen, NULL, _screen, NULL);
	SDL_BlitSurface(old_tmpscreen, NULL, _tmpscreen, NULL);
	
	// Free the old surfaces
	SDL_FreeSurface(old_screen);
	free(old_tmpscreen->pixels);
	SDL_FreeSurface(old_tmpscreen);

	// Blit everything to the screen
	update_screen();
	
	// Make sure that an EVENT_SCREEN_CHANGED gets sent later
	_modeChanged = true;
}

void OSystem_SDL_OpenGL::update_screen() {

	StackLock lock(_graphicsMutex, this);	// Lock the mutex until this function ends

	// If the shake position changed, fill the dirty area with blackness
	if (_currentShakePos != _newShakePos) {
		if (_usingOpenGL) {
			// Top black border
			SDL_Rect blackrect = {
			  0, 
			  0, // _glScreenStart, 
			  _screenWidth, 
			  _newShakePos + _glScreenStart
			};
		
			SDL_FillRect(tmpSurface, &blackrect, 0);
			fb2gl.blit16(tmpSurface, 1, &blackrect, 0, 0);
		} else { // SDL backend
			SDL_Rect blackrect = {0, 0, _screenWidth * _scaleFactor, _newShakePos * _scaleFactor};

			if (_adjustAspectRatio)
				blackrect.h = real2Aspect(blackrect.h - 1) + 1;

			SDL_FillRect(_hwscreen, &blackrect, 0);
		}

		_currentShakePos = _newShakePos;

		_forceFull = true;
	}

	// Make sure the mouse is drawn, if it should be drawn.
	draw_mouse();
	
	// Check whether the palette was changed in the meantime and update the
	// screen surface accordingly. 
	if (_paletteDirtyEnd != 0) {
		SDL_SetColors(_screen, _currentPalette + _paletteDirtyStart, 
			_paletteDirtyStart,
			_paletteDirtyEnd - _paletteDirtyStart);
		
		_paletteDirtyEnd = 0;

		_forceFull = true;
	}

	// Force a full redraw if requested
	if (_forceFull) {
		_num_dirty_rects = 1;

		_dirty_rect_list[0].x = 0;
		_dirty_rect_list[0].y = 0;
		_dirty_rect_list[0].w = _screenWidth;
		_dirty_rect_list[0].h = _screenHeight;
	}

	// Only draw anything if necessary
	if (_num_dirty_rects > 0) {
	
		SDL_Rect *r; 
		SDL_Rect dst;
		uint32 srcPitch, dstPitch;
		SDL_Rect *last_rect = _dirty_rect_list + _num_dirty_rects;

		
		if (_usingOpenGL) {
		
			if (!_overlayVisible) {
				for (r = _dirty_rect_list; r != last_rect; ++r) {
					dst = *r;
					dst.x++;	// Shift rect by one since 2xSai needs to acces the data around
					dst.y++;	// any pixel to scale it, and we want to avoid mem access crashes.
					if (SDL_BlitSurface(_screen, r, _tmpscreen, &dst) != 0)
						error("SDL_BlitSurface failed: %s", SDL_GetError());
				}
			}
			
			// Almost the same thing as SDL_UpdateRects
			fb2gl.blit16(
			    _tmpscreen, 
			    _num_dirty_rects, 
			    _dirty_rect_list, 
			    0,
			    _currentShakePos + _glScreenStart
			);

			int _glBottomOfGameScreen = _screenHeight + 
			  _glScreenStart + _currentShakePos; 

			// Bottom black border height
			tmpBlackRect.h = _glBottomOfTexture - _glBottomOfGameScreen;
			if (_adjustAspectRatio && tmpBlackRect.h > 0) {
				SDL_FillRect(tmpSurface, &tmpBlackRect, 0);
				fb2gl.blit16(tmpSurface, 1, &tmpBlackRect, 0,
				  _glBottomOfGameScreen);
			}

			fb2gl.display();
		} else { // SDL backend
			
			if (_scaler_proc == Normal1x && !_adjustAspectRatio) {
				SDL_Surface *target = _overlayVisible ? _tmpscreen : _screen;
				for (r = _dirty_rect_list; r != last_rect; ++r) {
					dst = *r;
					
					if (_overlayVisible) {
						// FIXME: I don't understand why this is necessary...
						dst.x--;
						dst.y--;
					}
					dst.y += _currentShakePos;
					if (SDL_BlitSurface(target, r, _hwscreen, &dst) != 0)
						error("SDL_BlitSurface failed: %s", SDL_GetError());
				}
			} else {
				if (!_overlayVisible) {
					for (r = _dirty_rect_list; r != last_rect; ++r) {
						dst = *r;
						dst.x++;	// Shift rect by one since 2xSai needs to acces the data around
						dst.y++;	// any pixel to scale it, and we want to avoid mem access crashes.
						if (SDL_BlitSurface(_screen, r, _tmpscreen, &dst) != 0)
							error("SDL_BlitSurface failed: %s", SDL_GetError());
					}
				}
	
				SDL_LockSurface(_tmpscreen);
				SDL_LockSurface(_hwscreen);
			
				srcPitch = _tmpscreen->pitch;
				dstPitch = _hwscreen->pitch;
			
				for (r = _dirty_rect_list; r != last_rect; ++r) {
					register int dst_y = r->y + _currentShakePos;
					register int dst_h = 0;
					register int orig_dst_y = 0;

					if (dst_y < _screenHeight) {
						dst_h = r->h;
						if (dst_h > _screenHeight - dst_y)
							dst_h = _screenHeight - dst_y;
			
							dst_y *= _scaleFactor;
			
							if (_adjustAspectRatio) {
								orig_dst_y = dst_y;
								dst_y = real2Aspect(dst_y);
							}

							_scaler_proc((byte *)_tmpscreen->pixels + (r->x * 2 + 2) + (r->y + 1) * srcPitch, srcPitch,
							(byte *)_hwscreen->pixels + r->x * 2 * _scaleFactor + dst_y * dstPitch, dstPitch, r->w, dst_h);
					}
				
					r->x *= _scaleFactor;
					r->y = dst_y;
					r->w *= _scaleFactor;
					r->h = dst_h * _scaleFactor;

					if (_adjustAspectRatio && orig_dst_y / _scaleFactor < _screenHeight)
						r->h = stretch200To240((uint8 *) _hwscreen->pixels, dstPitch, r->w, r->h, r->x, r->y, orig_dst_y);
				}
			
				SDL_UnlockSurface(_tmpscreen);
				SDL_UnlockSurface(_hwscreen);
			}
			
			// Readjust the dirty rect list in case we are doing a full update.
			// This is necessary if shaking is active.
			if (_forceFull) {
				_dirty_rect_list[0].y = 0;
				_dirty_rect_list[0].h = (_adjustAspectRatio ? 240 : _screenHeight) * _scaleFactor;
			}
			
			// Finally, blit all our changes to the screen
			SDL_UpdateRects(_hwscreen, _num_dirty_rects, _dirty_rect_list);
		} // END OF "SDL backend"
	} // if (num_dirty_rects > 0) ...

	_num_dirty_rects = 0;
	_forceFull = false;
}

/*
bool OSystem_SDL_OpenGL::poll_event(Event *event) {
	SDL_Event ev;
	ev.type = 0;


	SDL_PeepEvents(&ev, 1, SDL_GETEVENT, SDL_VIDEORESIZEMASK);

	if (_usingOpenGL && ev.type == SDL_VIDEORESIZE) {
	      int w = ev.resize.w; 
	      int h = ev.resize.h;
	      glViewport(0, 0, (GLsizei)w, (GLsizei)h);
	      glMatrixMode(GL_PROJECTION);
	      glLoadIdentity();
	      glOrtho(-1.0,1.0,-1.0,1.0,-1.0,1.0);
	      _glWindow.w = w;
	      _glWindow.h = h;
	}

	return OSystem_SDL_Common::poll_event(event);
}
*/

uint32 OSystem_SDL_OpenGL::property(int param, Property *value) {

	StackLock lock(_graphicsMutex, this); // Lock the mutex until this function ends

	if (param == PROP_TOGGLE_FULLSCREEN) {
		if (!_usingOpenGL)
			assert(_hwscreen != 0);
		_full_screen ^= true;
#ifdef MACOSX
		// On OS X, SDL_WM_ToggleFullScreen is currently not implemented. Worse,
		// it still always returns -1. So we simply don't call it at all and
		// use hotswap_gfx_mode() directly to switch to fullscreen mode.
		hotswap_gfx_mode();
#else
		SDL_Surface *_tmpScreen;
		if (_usingOpenGL) {
			_tmpScreen = fb2gl.getScreen();
		} 
		else { // SDL backend
			_tmpScreen = _hwscreen;
		}

		if (!SDL_WM_ToggleFullScreen(_tmpScreen)) {
			// if ToggleFullScreen fails, achieve the same effect with hotswap gfx mode
			hotswap_gfx_mode();
		}
#endif

		return 1;
	} else if (param == PROP_TOGGLE_ASPECT_RATIO) {

		if (_usingOpenGL) {
			_adjustAspectRatio ^= true;
			if (!_adjustAspectRatio) {
				// Don't use the whole screen (black borders)
				fb2gl.init(0, 0, 0, 15, _glFlags);
				_glScreenStart = _glBorderHeight;

				// Top black border
				SDL_Rect blackrect = {
				  0, 
				  0, // _glScreenStart, 
				  _screenWidth, 
				  _newShakePos + _glScreenStart
				};
		
				SDL_FillRect(tmpSurface, &blackrect, 0);
				fb2gl.blit16(tmpSurface, 1, &blackrect, 0, 0);
				
				// Bottom black border
				int _glBottomOfGameScreen = _screenHeight + 
				  _glScreenStart + _currentShakePos; 

				tmpBlackRect.h = _glBottomOfTexture - 
				  _glBottomOfGameScreen;
				
				SDL_FillRect(tmpSurface, &tmpBlackRect, 0);
				fb2gl.blit16(tmpSurface, 1, &tmpBlackRect, 0,
				  _glBottomOfGameScreen);
			} else {
				// Use the whole screen
				fb2gl.init(0, 0, 0, 72, _glFlags);
				_glScreenStart = 0;
			}

			SDL_Rect redraw = {0, 0, _screenWidth, _screenHeight};
			fb2gl.blit16(_tmpscreen, 1, &redraw, 0, _glScreenStart);
			fb2gl.display();
		} else {
			if (_screenHeight == 200) {
				assert(_hwscreen != 0);
				_adjustAspectRatio ^= true;
				hotswap_gfx_mode();
			}
		}

	} else if (param == PROP_SET_GFX_MODE) {

		if (value->gfx_mode > 10) { // OpenGL modes
			if (!_usingOpenGL) {
				_usingOpenGL = true;
				_mode = GFX_NORMAL;
				_scaleFactor = 1;
				_scaler_proc = Normal1x;
				hotswap_gfx_mode();
			}
		}
	  
		switch(value->gfx_mode) {
			case GFX_BILINEAR: // Bilinear Filtering (on/off)
				_glBilinearFilter ^= true;
				fb2gl.setBilinearMode(_glBilinearFilter);
				break;
			default: // SDL backend
				if (value->gfx_mode >= 10)
				  return 0;

				_mode = value->gfx_mode;

				if (_usingOpenGL) {
					_glBilinearFilter = false;
					_usingOpenGL = false;
				}
				
				hotswap_gfx_mode();
		};

/*		if (_usingOpenGL) {
			SDL_Rect redraw = {0, 0, _screenWidth, _screenHeight};
			fb2gl.blit16(_tmpscreen, 1, &redraw, 0, _glScreenStart);
			fb2gl.display();
		}*/

		return 1;
	}

	return OSystem_SDL_Common::property(param, value);
}

bool OSystem_SDL_OpenGL::save_screenshot(const char *filename) {
	// FIXME: I don't know how to do this yet.
	if (_usingOpenGL)
		return false;

	StackLock lock(_graphicsMutex, this);	// Lock the mutex until this function ends

	assert(_hwscreen != NULL);
	SDL_SaveBMP(_hwscreen, filename);
	return true;
}
