aboutsummaryrefslogtreecommitdiffstats
path: root/distrib/sdl-1.2.15/test/testgamma.c
blob: 70f4b3cb4da392311a0a756223261ac84e581039 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197

/* 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);
}