Mercurial > sdl-ios-xcode
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 |
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/* 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); }