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1 /* |
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2 * testpalette.c |
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3 * |
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4 * A simple test of runtime palette modification for animation |
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5 * (using the SDL_SetPalette() API). |
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6 */ |
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7 |
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8 #include <stdio.h> |
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9 #include <stdlib.h> |
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10 #include <string.h> |
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11 #include <math.h> |
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12 |
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13 /* This isn't in the Windows headers */ |
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14 #ifndef M_PI |
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15 #define M_PI 3.14159265358979323846 |
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16 #endif |
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17 |
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18 #include "SDL.h" |
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19 |
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20 /* screen size */ |
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21 #define SCRW 640 |
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22 #define SCRH 480 |
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23 |
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24 #define NBOATS 5 |
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25 #define SPEED 2 |
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26 |
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27 #ifndef MIN |
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28 #define MIN(a, b) ((a) < (b) ? (a) : (b)) |
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29 #endif |
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30 #ifndef MAX |
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31 #define MAX(a, b) ((a) > (b) ? (a) : (b)) |
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32 #endif |
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33 |
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34 /* |
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35 * wave colours: Made by taking a narrow cross-section of a wave picture |
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36 * in Gimp, saving in PPM ascii format and formatting with Emacs macros. |
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37 */ |
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38 static SDL_Color wavemap[] = { |
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39 {0,2,103}, {0,7,110}, {0,13,117}, {0,19,125}, |
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40 {0,25,133}, {0,31,141}, {0,37,150}, {0,43,158}, |
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41 {0,49,166}, {0,55,174}, {0,61,182}, {0,67,190}, |
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42 {0,73,198}, {0,79,206}, {0,86,214}, {0,96,220}, |
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43 {5,105,224}, {12,112,226}, {19,120,227}, {26,128,229}, |
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44 {33,135,230}, {40,143,232}, {47,150,234}, {54,158,236}, |
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45 {61,165,238}, {68,173,239}, {75,180,241}, {82,188,242}, |
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46 {89,195,244}, {96,203,246}, {103,210,248}, {112,218,250}, |
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47 {124,224,250}, {135,226,251}, {146,229,251}, {156,231,252}, |
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48 {167,233,252}, {178,236,252}, {189,238,252}, {200,240,252}, |
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49 {211,242,252}, {222,244,252}, {233,247,252}, {242,249,252}, |
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50 {237,250,252}, {209,251,252}, {174,251,252}, {138,252,252}, |
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51 {102,251,252}, {63,250,252}, {24,243,252}, {7,225,252}, |
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52 {4,203,252}, {3,181,252}, {2,158,252}, {1,136,251}, |
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53 {0,111,248}, {0,82,234}, {0,63,213}, {0,50,192}, |
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54 {0,39,172}, {0,28,152}, {0,17,132}, {0,7,114} |
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55 }; |
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56 |
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57 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */ |
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58 static void quit(int rc) |
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59 { |
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60 SDL_Quit(); |
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61 exit(rc); |
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62 } |
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63 |
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64 static void sdlerr(char *when) |
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65 { |
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66 fprintf(stderr, "SDL error: %s: %s\n", when, SDL_GetError()); |
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67 quit(1); |
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68 } |
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69 |
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70 /* create a background surface */ |
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71 static SDL_Surface *make_bg(SDL_Surface *screen, int startcol) |
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72 { |
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73 int i; |
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74 SDL_Surface *bg = SDL_CreateRGBSurface(SDL_SWSURFACE, screen->w, screen->h, |
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75 8, 0, 0, 0, 0); |
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76 if(!bg) |
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77 sdlerr("creating background surface"); |
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78 |
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79 /* set the palette to the logical screen palette so that blits |
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80 won't be translated */ |
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81 SDL_SetColors(bg, screen->format->palette->colors, 0, 256); |
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82 |
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83 /* Make a wavy background pattern using colours 0-63 */ |
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84 if(SDL_LockSurface(bg) < 0) |
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85 sdlerr("locking background"); |
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86 for(i = 0; i < SCRH; i++) { |
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87 Uint8 *p = (Uint8 *)bg->pixels + i * bg->pitch; |
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88 int j, d; |
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89 d = 0; |
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90 for(j = 0; j < SCRW; j++) { |
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91 int v = MAX(d, -2); |
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92 v = MIN(v, 2); |
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93 if(i > 0) |
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94 v += p[-bg->pitch] + 65 - startcol; |
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95 p[j] = startcol + (v & 63); |
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96 d += ((rand() >> 3) % 3) - 1; |
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97 } |
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98 } |
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99 SDL_UnlockSurface(bg); |
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100 return(bg); |
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101 } |
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102 |
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103 /* |
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104 * Return a surface flipped horisontally. Only works for 8bpp; |
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105 * extension to arbitrary bitness is left as an exercise for the reader. |
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106 */ |
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107 static SDL_Surface *hflip(SDL_Surface *s) |
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108 { |
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109 int i; |
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110 SDL_Surface *z = SDL_CreateRGBSurface(SDL_SWSURFACE, s->w, s->h, 8, |
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111 0, 0, 0, 0); |
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112 /* copy palette */ |
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113 SDL_SetColors(z, s->format->palette->colors, |
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114 0, s->format->palette->ncolors); |
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115 if(SDL_LockSurface(s) < 0 || SDL_LockSurface(z) < 0) |
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116 sdlerr("locking flip images"); |
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117 |
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118 for(i = 0; i < s->h; i++) { |
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119 int j; |
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120 Uint8 *from = (Uint8 *)s->pixels + i * s->pitch; |
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121 Uint8 *to = (Uint8 *)z->pixels + i * z->pitch + s->w - 1; |
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122 for(j = 0; j < s->w; j++) |
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123 to[-j] = from[j]; |
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124 } |
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125 |
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126 SDL_UnlockSurface(z); |
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127 SDL_UnlockSurface(s); |
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128 return z; |
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129 } |
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130 |
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131 int main(int argc, char **argv) |
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132 { |
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133 SDL_Color cmap[256]; |
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134 SDL_Surface *screen; |
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135 SDL_Surface *bg; |
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136 SDL_Surface *boat[2]; |
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137 unsigned vidflags = 0; |
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138 unsigned start; |
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139 int fade_max = 400; |
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140 int fade_level, fade_dir; |
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141 int boatcols, frames, i, red; |
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142 int boatx[NBOATS], boaty[NBOATS], boatdir[NBOATS]; |
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143 int gamma_fade = 0; |
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144 int gamma_ramp = 0; |
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145 |
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146 if(SDL_Init(SDL_INIT_VIDEO) < 0) |
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147 sdlerr("initialising SDL"); |
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148 |
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149 while(--argc) { |
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150 ++argv; |
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151 if(strcmp(*argv, "-hw") == 0) |
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152 vidflags |= SDL_HWSURFACE; |
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153 else if(strcmp(*argv, "-fullscreen") == 0) |
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154 vidflags |= SDL_FULLSCREEN; |
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155 else if(strcmp(*argv, "-nofade") == 0) |
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156 fade_max = 1; |
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157 else if(strcmp(*argv, "-gamma") == 0) |
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158 gamma_fade = 1; |
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159 else if(strcmp(*argv, "-gammaramp") == 0) |
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160 gamma_ramp = 1; |
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161 else { |
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162 fprintf(stderr, |
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163 "usage: testpalette " |
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164 " [-hw] [-fullscreen] [-nofade] [-gamma] [-gammaramp]\n"); |
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165 quit(1); |
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166 } |
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167 } |
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168 |
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169 /* Ask explicitly for 8bpp and a hardware palette */ |
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170 if((screen = SDL_SetVideoMode(SCRW, SCRH, 8, vidflags | SDL_HWPALETTE)) == NULL) { |
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171 fprintf(stderr, "error setting %dx%d 8bpp indexed mode: %s\n", |
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172 SCRW, SCRH, SDL_GetError()); |
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173 quit(1); |
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174 } |
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175 |
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176 if (vidflags & SDL_FULLSCREEN) SDL_ShowCursor (SDL_FALSE); |
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177 |
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178 if((boat[0] = SDL_LoadBMP("sail.bmp")) == NULL) |
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179 sdlerr("loading sail.bmp"); |
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180 /* We've chosen magenta (#ff00ff) as colour key for the boat */ |
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181 SDL_SetColorKey(boat[0], SDL_SRCCOLORKEY | SDL_RLEACCEL, |
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182 SDL_MapRGB(boat[0]->format, 0xff, 0x00, 0xff)); |
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183 boatcols = boat[0]->format->palette->ncolors; |
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184 boat[1] = hflip(boat[0]); |
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185 SDL_SetColorKey(boat[1], SDL_SRCCOLORKEY | SDL_RLEACCEL, |
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186 SDL_MapRGB(boat[1]->format, 0xff, 0x00, 0xff)); |
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187 |
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188 /* |
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189 * First set the physical screen palette to black, so the user won't |
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190 * see our initial drawing on the screen. |
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191 */ |
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192 memset(cmap, 0, sizeof(cmap)); |
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193 SDL_SetPalette(screen, SDL_PHYSPAL, cmap, 0, 256); |
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194 |
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195 /* |
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196 * Proper palette management is important when playing games with the |
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197 * colormap. We have divided the palette as follows: |
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198 * |
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199 * index 0..(boatcols-1): used for the boat |
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200 * index boatcols..(boatcols+63): used for the waves |
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201 */ |
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202 SDL_SetPalette(screen, SDL_LOGPAL, |
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203 boat[0]->format->palette->colors, 0, boatcols); |
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204 SDL_SetPalette(screen, SDL_LOGPAL, wavemap, boatcols, 64); |
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205 |
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206 /* |
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207 * Now the logical screen palette is set, and will remain unchanged. |
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208 * The boats already have the same palette so fast blits can be used. |
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209 */ |
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210 memcpy(cmap, screen->format->palette->colors, 256 * sizeof(SDL_Color)); |
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211 |
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212 /* save the index of the red colour for later */ |
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213 red = SDL_MapRGB(screen->format, 0xff, 0x00, 0x00); |
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214 |
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215 bg = make_bg(screen, boatcols); /* make a nice wavy background surface */ |
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216 |
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217 /* initial screen contents */ |
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218 if(SDL_BlitSurface(bg, NULL, screen, NULL) < 0) |
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219 sdlerr("blitting background to screen"); |
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220 SDL_Flip(screen); /* actually put the background on screen */ |
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221 |
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222 /* determine initial boat placements */ |
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223 for(i = 0; i < NBOATS; i++) { |
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224 boatx[i] = (rand() % (SCRW + boat[0]->w)) - boat[0]->w; |
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225 boaty[i] = i * (SCRH - boat[0]->h) / (NBOATS - 1); |
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226 boatdir[i] = ((rand() >> 5) & 1) * 2 - 1; |
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227 } |
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228 |
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229 start = SDL_GetTicks(); |
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230 frames = 0; |
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231 fade_dir = 1; |
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232 fade_level = 0; |
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233 do { |
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234 SDL_Event e; |
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235 SDL_Rect updates[NBOATS]; |
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236 SDL_Rect r; |
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237 int redphase; |
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238 |
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239 /* A small event loop: just exit on any key or mouse button event */ |
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240 while(SDL_PollEvent(&e)) { |
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241 if(e.type == SDL_KEYDOWN || e.type == SDL_QUIT |
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242 || e.type == SDL_MOUSEBUTTONDOWN) { |
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243 if(fade_dir < 0) |
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244 fade_level = 0; |
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245 fade_dir = -1; |
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246 } |
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247 } |
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248 |
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249 /* move boats */ |
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250 for(i = 0; i < NBOATS; i++) { |
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251 int old_x = boatx[i]; |
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252 /* update boat position */ |
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253 boatx[i] += boatdir[i] * SPEED; |
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254 if(boatx[i] <= -boat[0]->w || boatx[i] >= SCRW) |
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255 boatdir[i] = -boatdir[i]; |
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256 |
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257 /* paint over the old boat position */ |
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258 r.x = old_x; |
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259 r.y = boaty[i]; |
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260 r.w = boat[0]->w; |
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261 r.h = boat[0]->h; |
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262 if(SDL_BlitSurface(bg, &r, screen, &r) < 0) |
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263 sdlerr("blitting background"); |
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264 |
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265 /* construct update rectangle (bounding box of old and new pos) */ |
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266 updates[i].x = MIN(old_x, boatx[i]); |
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267 updates[i].y = boaty[i]; |
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268 updates[i].w = boat[0]->w + SPEED; |
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269 updates[i].h = boat[0]->h; |
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270 /* clip update rectangle to screen */ |
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271 if(updates[i].x < 0) { |
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272 updates[i].w += updates[i].x; |
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273 updates[i].x = 0; |
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274 } |
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275 if(updates[i].x + updates[i].w > SCRW) |
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276 updates[i].w = SCRW - updates[i].x; |
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277 } |
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278 |
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279 for(i = 0; i < NBOATS; i++) { |
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280 /* paint boat on new position */ |
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281 r.x = boatx[i]; |
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282 r.y = boaty[i]; |
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283 if(SDL_BlitSurface(boat[(boatdir[i] + 1) / 2], NULL, |
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284 screen, &r) < 0) |
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285 sdlerr("blitting boat"); |
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286 } |
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287 |
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288 /* cycle wave palette */ |
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289 for(i = 0; i < 64; i++) |
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290 cmap[boatcols + ((i + frames) & 63)] = wavemap[i]; |
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291 |
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292 if(fade_dir) { |
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293 /* Fade the entire palette in/out */ |
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294 fade_level += fade_dir; |
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295 |
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296 if(gamma_fade) { |
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297 /* Fade linearly in gamma level (lousy) */ |
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298 float level = (float)fade_level / fade_max; |
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299 if(SDL_SetGamma(level, level, level) < 0) |
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300 sdlerr("setting gamma"); |
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301 |
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302 } else if(gamma_ramp) { |
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303 /* Fade using gamma ramp (better) */ |
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304 Uint16 ramp[256]; |
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305 for(i = 0; i < 256; i++) |
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306 ramp[i] = (i * fade_level / fade_max) << 8; |
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307 if(SDL_SetGammaRamp(ramp, ramp, ramp) < 0) |
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308 sdlerr("setting gamma ramp"); |
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309 |
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310 } else { |
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311 /* Fade using direct palette manipulation (best) */ |
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312 memcpy(cmap, screen->format->palette->colors, |
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313 boatcols * sizeof(SDL_Color)); |
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314 for(i = 0; i < boatcols + 64; i++) { |
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315 cmap[i].r = cmap[i].r * fade_level / fade_max; |
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316 cmap[i].g = cmap[i].g * fade_level / fade_max; |
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317 cmap[i].b = cmap[i].b * fade_level / fade_max; |
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318 } |
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319 } |
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320 if(fade_level == fade_max) |
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321 fade_dir = 0; |
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322 } |
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323 |
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324 /* pulse the red colour (done after the fade, for a night effect) */ |
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325 redphase = frames % 64; |
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326 cmap[red].r = (int)(255 * sin(redphase * M_PI / 63)); |
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327 |
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328 SDL_SetPalette(screen, SDL_PHYSPAL, cmap, 0, boatcols + 64); |
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329 |
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330 /* update changed areas of the screen */ |
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331 SDL_UpdateRects(screen, NBOATS, updates); |
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332 frames++; |
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333 } while(fade_level > 0); |
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334 |
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335 printf("%d frames, %.2f fps\n", |
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336 frames, 1000.0 * frames / (SDL_GetTicks() - start)); |
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337 |
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338 if (vidflags & SDL_FULLSCREEN) SDL_ShowCursor (SDL_TRUE); |
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339 SDL_Quit(); |
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340 return 0; |
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341 } |
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342 |