Mercurial > sdl-ios-xcode
view test/testgamma.c @ 3877:81f66f258d77 SDL-1.2
Fixed bug #281
------- Comment #2 From Christian Walther 2006-07-23 07:37 [reply] -------
Wow, that was an interesting bug to chase. It was a timing issue: it seems that
for some reason, a certain time must pass between ShowMenuBar() being called in
QZ_UnsetVideoMode() and the application quitting. Before rev. 1885, this delay
was provided by the slow hand-coded fade. With the asynchronous Core Graphics
fading introduced in rev. 1885, that delay was no longer present (most of the
time) and the bug became apparent. Adding an SDL_Delay(100) somewhere between
ShowMenuBar() and the end of QZ_VideoQuit() lowered the frequency of the bug
appearing from "almost every time" to "very rarely" here.
However, there is another solution: doing the ShowMenuBar() before releasing
the captured display instead of afterwards. Apparently, no delay is necessary
in that case, and it looks nicer to me anyway because it is the reverse order
of the way things are set up in the beginning: capture display - set video mode
- hide menu bar - ... - show menu bar - reset video mode - release captured
display. So, this is what the attached patch does.
In addition, I've taken the liberty of
- removing some unused code that I forgot to remove in rev. 1885,
- fixing two warnings about undeclared functions in SDL_QuartzVideo.m by
including OpenGL.h (whose name is a bit misleading - it only declares CGL
stuff, so there's no interference with SDL_opengl.h).
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 24 Sep 2006 01:27:40 +0000 |
parents | be9c9c8f6d53 |
children | 782fd950bd46 c121d94672cb |
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/* Bring up a window and manipulate the gamma on it */ #include <stdlib.h> #include <stdio.h> #include <string.h> #include <math.h> #include "SDL.h" /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */ static void quit(int rc) { SDL_Quit(); exit(rc); } /* Turn a normal gamma value into an appropriate gamma ramp */ void CalculateGamma(double gamma, Uint16 *ramp) { int i, value; gamma = 1.0 / gamma; for ( i=0; i<256; ++i ) { value = (int)(pow((double)i/256.0, gamma)*65535.0 + 0.5); if ( value > 65535 ) { value = 65535; } ramp[i] = (Uint16)value; } } /* This can be used as a general routine for all of the test programs */ int get_video_args(char *argv[], int *w, int *h, int *bpp, Uint32 *flags) { int i; *w = 640; *h = 480; *bpp = 0; *flags = SDL_SWSURFACE; for ( i=1; argv[i]; ++i ) { if ( strcmp(argv[i], "-width") == 0 ) { if ( argv[i+1] ) { *w = atoi(argv[++i]); } } else if ( strcmp(argv[i], "-height") == 0 ) { if ( argv[i+1] ) { *h = atoi(argv[++i]); } } else if ( strcmp(argv[i], "-bpp") == 0 ) { if ( argv[i+1] ) { *bpp = atoi(argv[++i]); } } else if ( strcmp(argv[i], "-fullscreen") == 0 ) { *flags |= SDL_FULLSCREEN; } else if ( strcmp(argv[i], "-hw") == 0 ) { *flags |= SDL_HWSURFACE; } else if ( strcmp(argv[i], "-hwpalette") == 0 ) { *flags |= SDL_HWPALETTE; } else break; } return i; } int main(int argc, char *argv[]) { SDL_Surface *screen; SDL_Surface *image; float gamma; int i; int w, h, bpp; Uint32 flags; Uint16 ramp[256]; Uint16 red_ramp[256]; Uint32 then, timeout; /* Check command line arguments */ argv += get_video_args(argv, &w, &h, &bpp, &flags); /* Initialize SDL */ if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) { fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError()); return(1); } /* Initialize the display, always use hardware palette */ screen = SDL_SetVideoMode(w, h, bpp, flags | SDL_HWPALETTE); if ( screen == NULL ) { fprintf(stderr, "Couldn't set %dx%d video mode: %s\n", w, h, SDL_GetError()); quit(1); } /* Set the window manager title bar */ SDL_WM_SetCaption("SDL gamma test", "testgamma"); /* Set the desired gamma, if any */ gamma = 1.0f; if ( *argv ) { gamma = (float)atof(*argv); } if ( SDL_SetGamma(gamma, gamma, gamma) < 0 ) { fprintf(stderr, "Unable to set gamma: %s\n", SDL_GetError()); quit(1); } #if 0 /* This isn't supported. Integrating the gamma ramps isn't exact */ /* See what gamma was actually set */ float real[3]; if ( SDL_GetGamma(&real[0], &real[1], &real[2]) < 0 ) { printf("Couldn't get gamma: %s\n", SDL_GetError()); } else { printf("Set gamma values: R=%2.2f, G=%2.2f, B=%2.2f\n", real[0], real[1], real[2]); } #endif /* Do all the drawing work */ image = SDL_LoadBMP("sample.bmp"); if ( image ) { SDL_Rect dst; dst.x = (screen->w - image->w)/2; dst.y = (screen->h - image->h)/2; dst.w = image->w; dst.h = image->h; SDL_BlitSurface(image, NULL, screen, &dst); SDL_UpdateRects(screen, 1, &dst); } /* Wait a bit, handling events */ then = SDL_GetTicks(); timeout = (5*1000); while ( (SDL_GetTicks()-then) < timeout ) { SDL_Event event; while ( SDL_PollEvent(&event) ) { switch (event.type) { case SDL_QUIT: /* Quit now */ timeout = 0; break; case SDL_KEYDOWN: switch (event.key.keysym.sym) { case SDLK_SPACE: /* Go longer.. */ timeout += (5*1000); break; case SDLK_UP: gamma += 0.2f; SDL_SetGamma(gamma, gamma, gamma); break; case SDLK_DOWN: gamma -= 0.2f; SDL_SetGamma(gamma, gamma, gamma); break; case SDLK_ESCAPE: timeout = 0; break; default: break; } break; } } } /* Perform a gamma flash to red using color ramps */ while ( gamma < 10.0 ) { /* Increase the red gamma and decrease everything else... */ gamma += 0.1f; CalculateGamma(gamma, red_ramp); CalculateGamma(1.0/gamma, ramp); SDL_SetGammaRamp(red_ramp, ramp, ramp); } /* Finish completely red */ memset(red_ramp, 255, sizeof(red_ramp)); memset(ramp, 0, sizeof(ramp)); SDL_SetGammaRamp(red_ramp, ramp, ramp); /* Now fade out to black */ for ( i=(red_ramp[0] >> 8); i >= 0; --i ) { memset(red_ramp, i, sizeof(red_ramp)); SDL_SetGammaRamp(red_ramp, NULL, NULL); } SDL_Delay(1*1000); SDL_Quit(); return(0); }