test/testgamma.c
changeset 0 74212992fb08
child 1151 be9c9c8f6d53
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/testgamma.c	Thu Apr 26 16:45:43 2001 +0000
@@ -0,0 +1,190 @@
+
+/* 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"
+
+/* 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());
+		exit(1);
+	}
+	atexit(SDL_Quit);
+
+	/* 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());
+		exit(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());
+		exit(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);
+
+	return(0);
+}