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Rev | Author | Line No. | Line |
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5098 | clevermous | 1 | /* |
2 | * Highly optimised dithering 16 bits -> 8 bits. |
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3 | * The formulas were taken in Mesa (Bob Mercier mercier@hollywood.cinenet.net). |
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4 | */ |
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5 | |||
6 | #include |
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7 | #include |
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8 | #include "zbuffer.h" |
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9 | /*#include |
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10 | |||
11 | #if defined(TGL_FEATURE_8_BITS) |
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12 | |||
13 | #define _R 5 |
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14 | #define _G 9 |
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15 | #define _B 5 |
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16 | #define _DX 4 |
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17 | #define _DY 4 |
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18 | #define _D (_DX*_DY) |
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19 | #define _MIX(r,g,b) ( ((g)<<6) | ((b)<<3) | (r) ) |
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20 | |||
21 | #define DITHER_TABLE_SIZE (1 << 15) |
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22 | |||
23 | #define DITHER_INDEX(r,g,b) ((b) + (g) * _B + (r) * (_B * _G)) |
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24 | |||
25 | #define MAXC 256 |
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26 | static int kernel8[_DY*_DX] = { |
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27 | |||
28 | 12 * MAXC, 4 * MAXC, 14 * MAXC, 6 * MAXC, |
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29 | 3 * MAXC, 11 * MAXC, 1 * MAXC, 9 * MAXC, |
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30 | 15 * MAXC, 7 * MAXC, 13 * MAXC, 5 * MAXC, |
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31 | }; |
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32 | |||
33 | /* we build the color table and the lookup table */ |
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34 | |||
35 | void ZB_initDither(ZBuffer *zb,int nb_colors, |
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36 | unsigned char *color_indexes,int *color_table) |
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37 | { |
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38 | int c,r,g,b,i,index,r1,g1,b1; |
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39 | |||
40 | if (nb_colors < (_R * _G * _B)) { |
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41 | fprintf(stderr,"zdither: not enough colors\n"); |
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42 | exit(1); |
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43 | } |
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44 | |||
45 | for(i=0;i |
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46 | |||
47 | zb->nb_colors=nb_colors; |
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48 | zb->ctable=gl_malloc(nb_colors * sizeof(int)); |
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49 | |||
50 | for (r = 0; r < _R; r++) { |
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51 | for (g = 0; g < _G; g++) { |
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52 | for (b = 0; b < _B; b++) { |
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53 | r1=(r*255) / (_R - 1); |
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54 | g1=(g*255) / (_G - 1); |
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55 | b1=(b*255) / (_B - 1); |
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56 | index=DITHER_INDEX(r,g,b); |
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57 | c=(r1 << 16) | (g1 << 8) | b1; |
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58 | zb->ctable[index]=c; |
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59 | color_table[index]=c; |
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60 | } |
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61 | } |
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62 | } |
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63 | |||
64 | zb->dctable=gl_malloc( DITHER_TABLE_SIZE ); |
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65 | |||
66 | for(i=0;i |
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67 | r=(i >> 12) & 0x7; |
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68 | g=(i >> 8) & 0xF; |
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69 | b=(i >> 3) & 0x7; |
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70 | index=DITHER_INDEX(r,g,b); |
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71 | zb->dctable[i]=color_indexes[index]; |
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72 | } |
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73 | } |
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74 | |||
75 | void ZB_closeDither(ZBuffer *zb) |
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76 | { |
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77 | gl_free(zb->ctable); |
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78 | gl_free(zb->dctable); |
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79 | } |
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80 | |||
81 | #if 0 |
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82 | int ZDither_lookupColor(int r,int g,int b) |
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83 | { |
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84 | unsigned char *ctable=zdither_color_table; |
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85 | return ctable[_MIX(_DITH0(_R, r), _DITH0(_G, g),_DITH0(_B, b))]; |
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86 | } |
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87 | #endif |
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88 | |||
89 | |||
90 | #define DITHER_PIXEL2(a) \ |
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91 | { \ |
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92 | register int v,t,r,g,c; \ |
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93 | v=*(unsigned int *)(pp+(a)); \ |
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94 | g=(v & 0x07DF07DF) + g_d; \ |
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95 | r=(((v & 0xF800F800) >> 2) + r_d) & 0x70007000; \ |
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96 | t=r | g; \ |
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97 | c=ctable[t & 0xFFFF] | (ctable[t >> 16] << 8); \ |
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98 | *(unsigned short *)(dest+(a))=c; \ |
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99 | } |
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100 | |||
101 | /* NOTE: all the memory access are 16 bit aligned, so if buf or |
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102 | linesize are not multiple of 2, it cannot work efficiently (or |
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103 | hang!) */ |
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104 | |||
105 | void ZB_ditherFrameBuffer(ZBuffer *zb,unsigned char *buf, |
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106 | int linesize) |
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107 | { |
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108 | int xk,yk,x,y,c1,c2; |
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109 | unsigned char *dest1; |
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110 | unsigned short *pp1; |
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111 | int r_d,g_d,b_d; |
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112 | unsigned char *ctable=zb->dctable; |
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113 | register unsigned char *dest; |
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114 | register unsigned short *pp; |
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115 | |||
116 | assert( ((long)buf & 1) == 0 && (linesize & 1) == 0); |
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117 | |||
118 | for(yk=0;yk<4;yk++) { |
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119 | for(xk=0;xk<4;xk+=2) { |
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120 | #if BYTE_ORDER == BIG_ENDIAN |
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121 | c1=kernel8[yk*4+xk+1]; |
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122 | c2=kernel8[yk*4+xk]; |
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123 | #else |
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124 | c1=kernel8[yk*4+xk]; |
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125 | c2=kernel8[yk*4+xk+1]; |
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126 | #endif |
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127 | r_d=((c1 << 2) & 0xF800) >> 2; |
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128 | g_d=(c1 >> 4) & 0x07C0; |
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129 | b_d=(c1 >> 9) & 0x001F; |
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130 | |||
131 | r_d|=(((c2 << 2) & 0xF800) >> 2) << 16; |
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132 | g_d|=((c2 >> 4) & 0x07C0) << 16; |
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133 | b_d|=((c2 >> 9) & 0x001F) << 16; |
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134 | g_d=b_d | g_d; |
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135 | |||
136 | dest1=buf + (yk * linesize) + xk; |
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137 | pp1=zb->pbuf + (yk * zb->xsize) + xk; |
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138 | |||
139 | for(y=yk;y |
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140 | dest=dest1; |
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141 | pp=pp1; |
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142 | for(x=xk;x |
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143 | |||
144 | DITHER_PIXEL2(0); |
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145 | DITHER_PIXEL2(1*4); |
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146 | DITHER_PIXEL2(2*4); |
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147 | DITHER_PIXEL2(3*4); |
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148 | |||
149 | pp+=16; |
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150 | dest+=16; |
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151 | } |
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152 | dest1+=linesize*4; |
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153 | pp1+=zb->xsize*4; |
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154 | } |
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155 | } |
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156 | } |
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157 | } |
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158 | |||
159 | #endif><>><>><>><>><>4;xk+=2)>4;yk++)>><>><>><>>>>>><>3)><3)>6)><6)> |