view test/testbitmap.c @ 689:5bb080d35049

Date: Tue, 19 Aug 2003 17:57:00 +0200 From: Stephane Marchesin Subject: Re: [SDL] [patch] MMX alpha blit patches with MMX detection I think everything is correct now. I've done as much testing as I could, but some real-world testing wouldn't hurt, I think. The patch is here : http://icps.u-strasbg.fr/~marchesin/sdl_mmxblit.patch If you do byte-by-byte comparison of the output between C and MMX functions, you'll notice that the results for 555 and 565 RGB alpha blits aren't exactly the same. This is because MMX functions for 555 and 565 RGB have an higher accuracy. If you want the exact same behaviour that's possible by masking the three lower alpha bits in the MMX functions. Just ask ! I removed one MMX function because after I fixed it to match its C equivalent, it revealed to be slower than the C version on a PIII (although a bit faster on an Athlon XP). I've also added MMX and PIII replacements for SDL_memcpy. Those provide some speed up in testvidinfo -benchmark (at least for me, under linux & X11).
author Sam Lantinga <slouken@libsdl.org>
date Fri, 22 Aug 2003 05:51:19 +0000
parents 74212992fb08
children 609543e2b3a1
line wrap: on
line source


/* Simple program:  Test bitmap blits */

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

#include "SDL.h"
#include "picture.xbm"

SDL_Surface *LoadXBM(SDL_Surface *screen, int w, int h, Uint8 *bits)
{
	SDL_Surface *bitmap;
	Uint8 *line;

	/* Allocate the bitmap */
	bitmap = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 1, 0, 0, 0, 0);
	if ( bitmap == NULL ) {
		fprintf(stderr, "Couldn't allocate bitmap: %s\n",
						SDL_GetError());
		return(NULL);
	}

	/* Copy the pixels */
	line = (Uint8 *)bitmap->pixels;
	w = (w+7)/8;
	while ( h-- ) {
		memcpy(line, bits, w);
		/* X11 Bitmap images have the bits reversed */
		{ int i, j; Uint8 *buf, byte;
			for ( buf=line, i=0; i<w; ++i, ++buf ) {
				byte = *buf;
				*buf = 0;
				for ( j=7; j>=0; --j ) {
					*buf |= (byte&0x01)<<j;
					byte >>= 1;
				}
			}
		}
		line += bitmap->pitch;
		bits += w;
	}
	return(bitmap);
}

int main(int argc, char *argv[])
{
	SDL_Surface *screen;
	SDL_Surface *bitmap;
	Uint8  video_bpp;
	Uint32 videoflags;
	Uint8 *buffer;
	int i, done;
	SDL_Event event;

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

	video_bpp = 0;
	videoflags = SDL_SWSURFACE;
	while ( argc > 1 ) {
		--argc;
		if ( strcmp(argv[argc-1], "-bpp") == 0 ) {
			video_bpp = atoi(argv[argc]);
			--argc;
		} else
		if ( strcmp(argv[argc], "-warp") == 0 ) {
			videoflags |= SDL_HWPALETTE;
		} else
		if ( strcmp(argv[argc], "-hw") == 0 ) {
			videoflags |= SDL_HWSURFACE;
		} else
		if ( strcmp(argv[argc], "-fullscreen") == 0 ) {
			videoflags |= SDL_FULLSCREEN;
		} else {
			fprintf(stderr,
			"Usage: %s [-bpp N] [-warp] [-hw] [-fullscreen]\n",
								argv[0]);
			exit(1);
		}
	}

	/* Set 640x480 video mode */
	if ( (screen=SDL_SetVideoMode(640,480,video_bpp,videoflags)) == NULL ) {
		fprintf(stderr, "Couldn't set 640x480x%d video mode: %s\n",
						video_bpp, SDL_GetError());
		exit(2);
	}

	/* Set the surface pixels and refresh! */
	if ( SDL_LockSurface(screen) < 0 ) {
		fprintf(stderr, "Couldn't lock the display surface: %s\n",
							SDL_GetError());
		exit(2);
	}
	buffer=(Uint8 *)screen->pixels;
	for ( i=0; i<screen->h; ++i ) {
		memset(buffer,(i*255)/screen->h, screen->pitch);
		buffer += screen->pitch;
	}
	SDL_UnlockSurface(screen);
	SDL_UpdateRect(screen, 0, 0, 0, 0);

	/* Load the bitmap */
	bitmap = LoadXBM(screen, picture_width, picture_height,
					(Uint8 *)picture_bits);
	if ( bitmap == NULL ) {
		exit(1);
	}

	/* Wait for a keystroke */
	done = 0;
	while ( !done ) {
		/* Check for events */
		while ( SDL_PollEvent(&event) ) {
			switch (event.type) {
				case SDL_MOUSEBUTTONDOWN: {
					SDL_Rect dst;

					dst.x = event.button.x - bitmap->w/2;
					dst.y = event.button.y - bitmap->h/2;
					dst.w = bitmap->w;
					dst.h = bitmap->h;
					SDL_BlitSurface(bitmap, NULL,
								screen, &dst);
					SDL_UpdateRects(screen,1,&dst);
					}
					break;
				case SDL_KEYDOWN:
					/* Any key press quits the app... */
					done = 1;
					break;
				case SDL_QUIT:
					done = 1;
					break;
				default:
					break;
			}
		}
	}
	SDL_FreeSurface(bitmap);
	return(0);
}