view test/testgamma.c @ 1207:c9ec00d3e8bc

To: sdl@libsdl.org From: Christian Walther <cwalther@gmx.ch> Date: Wed, 21 Dec 2005 13:39:39 +0100 Subject: [SDL] Another mouse bug patch for Mac OS X Oh my, yet another change in the quartz mouse handling code! :) The attached patch fixes the following bug: Calling SDL_WarpMouse() while the cursor is invisible and grabbed should only update SDL's internal mouse location, not try to warp the system cursor (which is not at that location, but fixed in the middle of the window). Otherwise, the next mouse motion event is wrong. Please apply. Thanks Christian
author Ryan C. Gordon <icculus@icculus.org>
date Wed, 21 Dec 2005 18:02:36 +0000
parents be9c9c8f6d53
children 782fd950bd46 c121d94672cb
line wrap: on
line source


/* 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);
}