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1 |
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2 /* Bring up a window and manipulate the gamma on it */ |
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3 |
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4 #include <stdlib.h> |
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5 #include <stdio.h> |
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6 #include <string.h> |
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7 #include <math.h> |
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8 |
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9 #include "SDL.h" |
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10 |
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11 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */ |
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12 static void quit(int rc) |
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13 { |
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14 SDL_Quit(); |
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15 exit(rc); |
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16 } |
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17 |
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18 /* Turn a normal gamma value into an appropriate gamma ramp */ |
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19 void CalculateGamma(double gamma, Uint16 *ramp) |
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20 { |
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21 int i, value; |
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22 |
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23 gamma = 1.0 / gamma; |
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24 for ( i=0; i<256; ++i ) { |
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25 value = (int)(pow((double)i/256.0, gamma)*65535.0 + 0.5); |
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26 if ( value > 65535 ) { |
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27 value = 65535; |
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28 } |
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29 ramp[i] = (Uint16)value; |
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30 } |
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31 } |
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32 |
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33 /* This can be used as a general routine for all of the test programs */ |
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34 int get_video_args(char *argv[], int *w, int *h, int *bpp, Uint32 *flags) |
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35 { |
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36 int i; |
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37 |
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38 *w = 640; |
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39 *h = 480; |
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40 *bpp = 0; |
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41 *flags = SDL_SWSURFACE; |
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42 |
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43 for ( i=1; argv[i]; ++i ) { |
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44 if ( strcmp(argv[i], "-width") == 0 ) { |
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45 if ( argv[i+1] ) { |
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46 *w = atoi(argv[++i]); |
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47 } |
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48 } else |
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49 if ( strcmp(argv[i], "-height") == 0 ) { |
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50 if ( argv[i+1] ) { |
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51 *h = atoi(argv[++i]); |
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52 } |
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53 } else |
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54 if ( strcmp(argv[i], "-bpp") == 0 ) { |
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55 if ( argv[i+1] ) { |
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56 *bpp = atoi(argv[++i]); |
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57 } |
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58 } else |
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59 if ( strcmp(argv[i], "-fullscreen") == 0 ) { |
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60 *flags |= SDL_FULLSCREEN; |
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61 } else |
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62 if ( strcmp(argv[i], "-hw") == 0 ) { |
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63 *flags |= SDL_HWSURFACE; |
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64 } else |
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65 if ( strcmp(argv[i], "-hwpalette") == 0 ) { |
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66 *flags |= SDL_HWPALETTE; |
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67 } else |
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68 break; |
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69 } |
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70 return i; |
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71 } |
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72 |
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73 int main(int argc, char *argv[]) |
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74 { |
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75 SDL_Surface *screen; |
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76 SDL_Surface *image; |
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77 float gamma; |
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78 int i; |
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79 int w, h, bpp; |
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80 Uint32 flags; |
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81 Uint16 ramp[256]; |
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82 Uint16 red_ramp[256]; |
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83 Uint32 then, timeout; |
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84 |
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85 /* Check command line arguments */ |
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86 argv += get_video_args(argv, &w, &h, &bpp, &flags); |
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87 |
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88 /* Initialize SDL */ |
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89 if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) { |
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90 fprintf(stderr, |
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91 "Couldn't initialize SDL: %s\n", SDL_GetError()); |
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92 return(1); |
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93 } |
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94 |
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95 /* Initialize the display, always use hardware palette */ |
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96 screen = SDL_SetVideoMode(w, h, bpp, flags | SDL_HWPALETTE); |
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97 if ( screen == NULL ) { |
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98 fprintf(stderr, "Couldn't set %dx%d video mode: %s\n", |
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99 w, h, SDL_GetError()); |
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100 quit(1); |
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101 } |
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102 |
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103 /* Set the window manager title bar */ |
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104 SDL_WM_SetCaption("SDL gamma test", "testgamma"); |
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105 |
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106 /* Set the desired gamma, if any */ |
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107 gamma = 1.0f; |
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108 if ( *argv ) { |
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109 gamma = (float)atof(*argv); |
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110 } |
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111 if ( SDL_SetGamma(gamma, gamma, gamma) < 0 ) { |
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112 fprintf(stderr, "Unable to set gamma: %s\n", SDL_GetError()); |
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113 quit(1); |
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114 } |
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115 |
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116 #if 0 /* This isn't supported. Integrating the gamma ramps isn't exact */ |
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117 /* See what gamma was actually set */ |
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118 float real[3]; |
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119 if ( SDL_GetGamma(&real[0], &real[1], &real[2]) < 0 ) { |
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120 printf("Couldn't get gamma: %s\n", SDL_GetError()); |
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121 } else { |
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122 printf("Set gamma values: R=%2.2f, G=%2.2f, B=%2.2f\n", |
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123 real[0], real[1], real[2]); |
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124 } |
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125 #endif |
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126 |
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127 /* Do all the drawing work */ |
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128 image = SDL_LoadBMP("sample.bmp"); |
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129 if ( image ) { |
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130 SDL_Rect dst; |
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131 |
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132 dst.x = (screen->w - image->w)/2; |
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133 dst.y = (screen->h - image->h)/2; |
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134 dst.w = image->w; |
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135 dst.h = image->h; |
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136 SDL_BlitSurface(image, NULL, screen, &dst); |
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137 SDL_UpdateRects(screen, 1, &dst); |
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138 } |
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139 |
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140 /* Wait a bit, handling events */ |
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141 then = SDL_GetTicks(); |
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142 timeout = (5*1000); |
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143 while ( (SDL_GetTicks()-then) < timeout ) { |
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144 SDL_Event event; |
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145 |
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146 while ( SDL_PollEvent(&event) ) { |
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147 switch (event.type) { |
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148 case SDL_QUIT: /* Quit now */ |
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149 timeout = 0; |
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150 break; |
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151 case SDL_KEYDOWN: |
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152 switch (event.key.keysym.sym) { |
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153 case SDLK_SPACE: /* Go longer.. */ |
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154 timeout += (5*1000); |
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155 break; |
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156 case SDLK_UP: |
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157 gamma += 0.2f; |
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158 SDL_SetGamma(gamma, gamma, gamma); |
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159 break; |
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160 case SDLK_DOWN: |
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161 gamma -= 0.2f; |
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162 SDL_SetGamma(gamma, gamma, gamma); |
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163 break; |
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164 case SDLK_ESCAPE: |
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165 timeout = 0; |
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166 break; |
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167 default: |
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168 break; |
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169 } |
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170 break; |
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171 } |
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172 } |
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173 } |
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174 |
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175 /* Perform a gamma flash to red using color ramps */ |
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176 while ( gamma < 10.0 ) { |
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177 /* Increase the red gamma and decrease everything else... */ |
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178 gamma += 0.1f; |
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179 CalculateGamma(gamma, red_ramp); |
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180 CalculateGamma(1.0/gamma, ramp); |
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181 SDL_SetGammaRamp(red_ramp, ramp, ramp); |
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182 } |
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183 /* Finish completely red */ |
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184 memset(red_ramp, 255, sizeof(red_ramp)); |
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185 memset(ramp, 0, sizeof(ramp)); |
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186 SDL_SetGammaRamp(red_ramp, ramp, ramp); |
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187 |
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188 /* Now fade out to black */ |
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189 for ( i=(red_ramp[0] >> 8); i >= 0; --i ) { |
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190 memset(red_ramp, i, sizeof(red_ramp)); |
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191 SDL_SetGammaRamp(red_ramp, NULL, NULL); |
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192 } |
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193 SDL_Delay(1*1000); |
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194 |
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195 SDL_Quit(); |
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196 return(0); |
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197 } |