view test/graywin.c @ 1555:780fd5b61df1

Fixed bug #89 Date: Sun, 23 Oct 2005 16:39:03 +0200 From: "A. Schmid" <sahib@phreaker.net> Subject: [SDL] no software surfaces with svgalib driver? Hi, I noticed that the SDL (1.2.9) svgalib driver only makes use of linear addressable (framebuffer) video modes. On older systems (like one of mine), linear addressable modes are often not available. Especially for cards with VESA VBE < 2.0 the svgalib vesa driver is unusable, since VESA only supports framebuffering for VBE 2.0 and later. The changes necessary to add support for software surfaces seem to be relatively small. I only had to hack src/video/svga/SDL_svgavideo.c (see attached patch). The code worked fine for me, but it is no more than a proof of concept and should be reviewed (probably has a memory leak when switching modes). It also uses the vgagl library (included in the svgalib package) and needs to be linked against it. -Alex
author Sam Lantinga <slouken@libsdl.org>
date Sun, 19 Mar 2006 12:05:16 +0000
parents d33645c36072
children 782fd950bd46 c121d94672cb
line wrap: on
line source


/* Simple program:  Fill a colormap with gray and stripe it down the screen */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include "SDL.h"

#ifdef TEST_VGA16 /* Define this if you want to test VGA 16-color video modes */
#define NUM_COLORS	16
#else
#define NUM_COLORS	256
#endif

/* Draw a randomly sized and colored box centered about (X,Y) */
void DrawBox(SDL_Surface *screen, int X, int Y, int width, int height)
{
	static unsigned int seeded = 0;
	SDL_Rect area;
	Uint32 color;
        Uint32 randc;

	/* Seed the random number generator */
	if ( seeded == 0 ) {
		srand(time(NULL));
		seeded = 1;
	}

	/* Get the bounds of the rectangle */
	area.w = (rand()%width);
	area.h = (rand()%height);
	area.x = X-(area.w/2);
	area.y = Y-(area.h/2);
        randc = (rand()%NUM_COLORS);

        if (screen->format->BytesPerPixel==1)
        {
            color = randc;
        }
        else
        {
            color = SDL_MapRGB(screen->format, randc, randc, randc);
        }

	/* Do it! */
	SDL_FillRect(screen, &area, color);
	if ( screen->flags & SDL_DOUBLEBUF ) {
		SDL_Flip(screen);
	} else {
		SDL_UpdateRects(screen, 1, &area);
	}
}

void DrawBackground(SDL_Surface *screen)
{
	int i, j, k;
	Uint8  *buffer;
	Uint16 *buffer16;
        Uint16 color;
        Uint8  gradient;

	/* Set the surface pixels and refresh! */
	/* Use two loops in case the surface is double-buffered (both sides) */

	for ( j=0; j<2; ++j ) {
		if ( SDL_LockSurface(screen) < 0 ) {
			fprintf(stderr, "Couldn't lock display surface: %s\n",
								SDL_GetError());
			return;
		}
		buffer = (Uint8 *)screen->pixels;

		if (screen->format->BytesPerPixel!=2) {
			for ( i=0; i<screen->h; ++i ) {
				memset(buffer,(i*(NUM_COLORS-1))/screen->h, screen->w * screen->format->BytesPerPixel);
				buffer += screen->pitch;
			}
		}
                else
                {
			for ( i=0; i<screen->h; ++i ) {
				gradient=((i*(NUM_COLORS-1))/screen->h);
                                color = SDL_MapRGB(screen->format, gradient, gradient, gradient);
                                buffer16=(Uint16*)buffer;
                                for (k=0; k<screen->w; k++)
                                {
                                   *(buffer16+k)=color;
                                }
				buffer += screen->pitch;
			}
                }

		SDL_UnlockSurface(screen);
		if ( screen->flags & SDL_DOUBLEBUF ) {
			SDL_Flip(screen);
		} else {
			SDL_UpdateRect(screen, 0, 0, 0, 0);
                        break;
		}
	}
}

SDL_Surface *CreateScreen(Uint16 w, Uint16 h, Uint8 bpp, Uint32 flags)
{
	SDL_Surface *screen;
	int i;
	SDL_Color palette[NUM_COLORS];

	/* Set the video mode */
	screen = SDL_SetVideoMode(w, h, bpp, flags);
	if ( screen == NULL ) {
		fprintf(stderr, "Couldn't set display mode: %s\n",
							SDL_GetError());
		return(NULL);
	}
	fprintf(stderr, "Screen is in %s mode\n",
		(screen->flags & SDL_FULLSCREEN) ? "fullscreen" : "windowed");

	if (bpp==8) {
		/* Set a gray colormap, reverse order from white to black */
		for ( i=0; i<NUM_COLORS; ++i ) {
			palette[i].r = (NUM_COLORS-1)-i * (256 / NUM_COLORS);
			palette[i].g = (NUM_COLORS-1)-i * (256 / NUM_COLORS);
			palette[i].b = (NUM_COLORS-1)-i * (256 / NUM_COLORS);
		}
		SDL_SetColors(screen, palette, 0, NUM_COLORS);
	}

	return(screen);
}

int main(int argc, char *argv[])
{
	SDL_Surface *screen;
	Uint32 videoflags;
	int    done;
	SDL_Event event;
	int width, height, bpp;

	/* Initialize SDL */
	if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {
		fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError());
		exit(1);
	}

	/* See if we try to get a hardware colormap */
	width = 640;
	height = 480;
	bpp = 8;
	videoflags = SDL_SWSURFACE;
	while ( argc > 1 ) {
		--argc;
		if ( argv[argc-1] && (strcmp(argv[argc-1], "-width") == 0) ) {
			width = atoi(argv[argc]);
			--argc;
		} else
		if ( argv[argc-1] && (strcmp(argv[argc-1], "-height") == 0) ) {
			height = atoi(argv[argc]);
			--argc;
		} else
		if ( argv[argc-1] && (strcmp(argv[argc-1], "-bpp") == 0) ) {
			bpp = atoi(argv[argc]);
			--argc;
		} else
		if ( argv[argc] && (strcmp(argv[argc], "-hw") == 0) ) {
			videoflags |= SDL_HWSURFACE;
		} else
		if ( argv[argc] && (strcmp(argv[argc], "-hwpalette") == 0) ) {
			videoflags |= SDL_HWPALETTE;
		} else
		if ( argv[argc] && (strcmp(argv[argc], "-flip") == 0) ) {
			videoflags |= SDL_DOUBLEBUF;
		} else
		if ( argv[argc] && (strcmp(argv[argc], "-noframe") == 0) ) {
			videoflags |= SDL_NOFRAME;
		} else
		if ( argv[argc] && (strcmp(argv[argc], "-resize") == 0) ) {
			videoflags |= SDL_RESIZABLE;
		} else
		if ( argv[argc] && (strcmp(argv[argc], "-fullscreen") == 0) ) {
			videoflags |= SDL_FULLSCREEN;
		} else {
			fprintf(stderr, "Usage: %s [-width] [-height] [-bpp] [-hw] [-hwpalette] [-flip] [-noframe] [-fullscreen] [-resize]\n",
								argv[0]);
			exit(1);
		}
	}

	/* Set a video mode */
	screen = CreateScreen(width, height, bpp, videoflags);
	if ( screen == NULL ) {
		exit(2);
	}
        
        DrawBackground(screen);
		
	/* Wait for a keystroke */
	done = 0;
	while ( !done && SDL_WaitEvent(&event) ) {
		switch (event.type) {
			case SDL_MOUSEBUTTONDOWN:
				DrawBox(screen, event.button.x, event.button.y, width, height);
				break;
			case SDL_KEYDOWN:
				/* Ignore ALT-TAB for windows */
				if ( (event.key.keysym.sym == SDLK_LALT) ||
				     (event.key.keysym.sym == SDLK_TAB) ) {
					break;
				}
				/* Center the mouse on <SPACE> */
				if ( event.key.keysym.sym == SDLK_SPACE ) {
					SDL_WarpMouse(width/2, height/2);
					break;
				}
				/* Toggle fullscreen mode on <RETURN> */
				if ( event.key.keysym.sym == SDLK_RETURN ) {
					videoflags ^= SDL_FULLSCREEN;
					screen = CreateScreen(
						screen->w, screen->h,
						screen->format->BitsPerPixel,
								videoflags);
					if ( screen == NULL ) {
						fprintf(stderr,
					"Couldn't toggle fullscreen mode\n");
						done = 1;
					}
                                        DrawBackground(screen);
					break;
				}
				/* Any other key quits the application... */
			case SDL_QUIT:
				done = 1;
				break;
			case SDL_VIDEOEXPOSE:
				DrawBackground(screen);
				break;
			case SDL_VIDEORESIZE:
					screen = CreateScreen(
						event.resize.w, event.resize.h,
						screen->format->BitsPerPixel,
								videoflags);
					if ( screen == NULL ) {
						fprintf(stderr,
					"Couldn't resize video mode\n");
						done = 1;
					}
					DrawBackground(screen);
				break;
			default:
				break;
		}
	}
	SDL_Quit();
	return(0);
}