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Rev | Author | Line No. | Line |
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6417 | ashmew2 | 1 | /* |
2 | * rdtarga.c |
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3 | * |
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4 | * Copyright (C) 1991-1996, Thomas G. Lane. |
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5 | * This file is part of the Independent JPEG Group's software. |
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6 | * For conditions of distribution and use, see the accompanying README file. |
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7 | * |
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8 | * This file contains routines to read input images in Targa format. |
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9 | * |
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10 | * These routines may need modification for non-Unix environments or |
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11 | * specialized applications. As they stand, they assume input from |
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12 | * an ordinary stdio stream. They further assume that reading begins |
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13 | * at the start of the file; start_input may need work if the |
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14 | * user interface has already read some data (e.g., to determine that |
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15 | * the file is indeed Targa format). |
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16 | * |
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17 | * Based on code contributed by Lee Daniel Crocker. |
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18 | */ |
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19 | |||
20 | #include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */ |
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21 | |||
22 | #ifdef TARGA_SUPPORTED |
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23 | |||
24 | |||
25 | /* Macros to deal with unsigned chars as efficiently as compiler allows */ |
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26 | |||
27 | #ifdef HAVE_UNSIGNED_CHAR |
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28 | typedef unsigned char U_CHAR; |
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29 | #define UCH(x) ((int) (x)) |
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30 | #else /* !HAVE_UNSIGNED_CHAR */ |
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31 | #ifdef CHAR_IS_UNSIGNED |
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32 | typedef char U_CHAR; |
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33 | #define UCH(x) ((int) (x)) |
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34 | #else |
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35 | typedef char U_CHAR; |
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36 | #define UCH(x) ((int) (x) & 0xFF) |
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37 | #endif |
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38 | #endif /* HAVE_UNSIGNED_CHAR */ |
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39 | |||
40 | |||
41 | #define ReadOK(file,buffer,len) (JFREAD(file,buffer,len) == ((size_t) (len))) |
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42 | |||
43 | |||
44 | /* Private version of data source object */ |
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45 | |||
46 | typedef struct _tga_source_struct * tga_source_ptr; |
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47 | |||
48 | typedef struct _tga_source_struct { |
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49 | struct cjpeg_source_struct pub; /* public fields */ |
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50 | |||
51 | j_compress_ptr cinfo; /* back link saves passing separate parm */ |
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52 | |||
53 | JSAMPARRAY colormap; /* Targa colormap (converted to my format) */ |
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54 | |||
55 | jvirt_sarray_ptr whole_image; /* Needed if funny input row order */ |
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56 | JDIMENSION current_row; /* Current logical row number to read */ |
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57 | |||
58 | /* Pointer to routine to extract next Targa pixel from input file */ |
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59 | JMETHOD(void, read_pixel, (tga_source_ptr sinfo)); |
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60 | |||
61 | /* Result of read_pixel is delivered here: */ |
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62 | U_CHAR tga_pixel[4]; |
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63 | |||
64 | int pixel_size; /* Bytes per Targa pixel (1 to 4) */ |
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65 | |||
66 | /* State info for reading RLE-coded pixels; both counts must be init to 0 */ |
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67 | int block_count; /* # of pixels remaining in RLE block */ |
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68 | int dup_pixel_count; /* # of times to duplicate previous pixel */ |
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69 | |||
70 | /* This saves the correct pixel-row-expansion method for preload_image */ |
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71 | JMETHOD(JDIMENSION, get_pixel_rows, (j_compress_ptr cinfo, |
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72 | cjpeg_source_ptr sinfo)); |
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73 | } tga_source_struct; |
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74 | |||
75 | |||
76 | /* For expanding 5-bit pixel values to 8-bit with best rounding */ |
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77 | |||
78 | static const UINT8 c5to8bits[32] = { |
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79 | 0, 8, 16, 25, 33, 41, 49, 58, |
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80 | 66, 74, 82, 90, 99, 107, 115, 123, |
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81 | 132, 140, 148, 156, 165, 173, 181, 189, |
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82 | 197, 206, 214, 222, 230, 239, 247, 255 |
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83 | }; |
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84 | |||
85 | |||
86 | |||
87 | LOCAL(int) |
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88 | read_byte (tga_source_ptr sinfo) |
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89 | /* Read next byte from Targa file */ |
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90 | { |
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91 | register FILE *infile = sinfo->pub.input_file; |
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92 | register int c; |
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93 | |||
94 | if ((c = getc(infile)) == EOF) |
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95 | ERREXIT(sinfo->cinfo, JERR_INPUT_EOF); |
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96 | return c; |
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97 | } |
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98 | |||
99 | |||
100 | LOCAL(void) |
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101 | read_colormap (tga_source_ptr sinfo, int cmaplen, int mapentrysize) |
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102 | /* Read the colormap from a Targa file */ |
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103 | { |
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104 | int i; |
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105 | |||
106 | /* Presently only handles 24-bit BGR format */ |
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107 | if (mapentrysize != 24) |
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108 | ERREXIT(sinfo->cinfo, JERR_TGA_BADCMAP); |
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109 | |||
110 | for (i = 0; i < cmaplen; i++) { |
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111 | sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo); |
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112 | sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo); |
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113 | sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo); |
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114 | } |
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115 | } |
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116 | |||
117 | |||
118 | /* |
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119 | * read_pixel methods: get a single pixel from Targa file into tga_pixel[] |
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120 | */ |
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121 | |||
122 | METHODDEF(void) |
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123 | read_non_rle_pixel (tga_source_ptr sinfo) |
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124 | /* Read one Targa pixel from the input file; no RLE expansion */ |
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125 | { |
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126 | register FILE *infile = sinfo->pub.input_file; |
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127 | register int i; |
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128 | |||
129 | for (i = 0; i < sinfo->pixel_size; i++) { |
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130 | sinfo->tga_pixel[i] = (U_CHAR) getc(infile); |
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131 | } |
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132 | } |
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133 | |||
134 | |||
135 | METHODDEF(void) |
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136 | read_rle_pixel (tga_source_ptr sinfo) |
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137 | /* Read one Targa pixel from the input file, expanding RLE data as needed */ |
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138 | { |
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139 | register FILE *infile = sinfo->pub.input_file; |
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140 | register int i; |
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141 | |||
142 | /* Duplicate previously read pixel? */ |
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143 | if (sinfo->dup_pixel_count > 0) { |
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144 | sinfo->dup_pixel_count--; |
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145 | return; |
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146 | } |
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147 | |||
148 | /* Time to read RLE block header? */ |
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149 | if (--sinfo->block_count < 0) { /* decrement pixels remaining in block */ |
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150 | i = read_byte(sinfo); |
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151 | if (i & 0x80) { /* Start of duplicate-pixel block? */ |
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152 | sinfo->dup_pixel_count = i & 0x7F; /* number of dups after this one */ |
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153 | sinfo->block_count = 0; /* then read new block header */ |
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154 | } else { |
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155 | sinfo->block_count = i & 0x7F; /* number of pixels after this one */ |
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156 | } |
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157 | } |
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158 | |||
159 | /* Read next pixel */ |
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160 | for (i = 0; i < sinfo->pixel_size; i++) { |
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161 | sinfo->tga_pixel[i] = (U_CHAR) getc(infile); |
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162 | } |
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163 | } |
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164 | |||
165 | |||
166 | /* |
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167 | * Read one row of pixels. |
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168 | * |
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169 | * We provide several different versions depending on input file format. |
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170 | */ |
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171 | |||
172 | |||
173 | METHODDEF(JDIMENSION) |
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174 | get_8bit_gray_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
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175 | /* This version is for reading 8-bit grayscale pixels */ |
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176 | { |
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177 | tga_source_ptr source = (tga_source_ptr) sinfo; |
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178 | register JSAMPROW ptr; |
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179 | register JDIMENSION col; |
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180 | |||
181 | ptr = source->pub.buffer[0]; |
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182 | for (col = cinfo->image_width; col > 0; col--) { |
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183 | (*source->read_pixel) (source); /* Load next pixel into tga_pixel */ |
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184 | *ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]); |
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185 | } |
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186 | return 1; |
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187 | } |
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188 | |||
189 | METHODDEF(JDIMENSION) |
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190 | get_8bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
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191 | /* This version is for reading 8-bit colormap indexes */ |
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192 | { |
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193 | tga_source_ptr source = (tga_source_ptr) sinfo; |
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194 | register int t; |
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195 | register JSAMPROW ptr; |
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196 | register JDIMENSION col; |
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197 | register JSAMPARRAY colormap = source->colormap; |
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198 | |||
199 | ptr = source->pub.buffer[0]; |
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200 | for (col = cinfo->image_width; col > 0; col--) { |
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201 | (*source->read_pixel) (source); /* Load next pixel into tga_pixel */ |
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202 | t = UCH(source->tga_pixel[0]); |
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203 | *ptr++ = colormap[0][t]; |
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204 | *ptr++ = colormap[1][t]; |
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205 | *ptr++ = colormap[2][t]; |
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206 | } |
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207 | return 1; |
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208 | } |
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209 | |||
210 | METHODDEF(JDIMENSION) |
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211 | get_16bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
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212 | /* This version is for reading 16-bit pixels */ |
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213 | { |
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214 | tga_source_ptr source = (tga_source_ptr) sinfo; |
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215 | register int t; |
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216 | register JSAMPROW ptr; |
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217 | register JDIMENSION col; |
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218 | |||
219 | ptr = source->pub.buffer[0]; |
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220 | for (col = cinfo->image_width; col > 0; col--) { |
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221 | (*source->read_pixel) (source); /* Load next pixel into tga_pixel */ |
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222 | t = UCH(source->tga_pixel[0]); |
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223 | t += UCH(source->tga_pixel[1]) << 8; |
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224 | /* We expand 5 bit data to 8 bit sample width. |
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225 | * The format of the 16-bit (LSB first) input word is |
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226 | * xRRRRRGGGGGBBBBB |
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227 | */ |
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228 | ptr[2] = (JSAMPLE) c5to8bits[t & 0x1F]; |
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229 | t >>= 5; |
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230 | ptr[1] = (JSAMPLE) c5to8bits[t & 0x1F]; |
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231 | t >>= 5; |
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232 | ptr[0] = (JSAMPLE) c5to8bits[t & 0x1F]; |
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233 | ptr += 3; |
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234 | } |
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235 | return 1; |
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236 | } |
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237 | |||
238 | METHODDEF(JDIMENSION) |
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239 | get_24bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
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240 | /* This version is for reading 24-bit pixels */ |
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241 | { |
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242 | tga_source_ptr source = (tga_source_ptr) sinfo; |
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243 | register JSAMPROW ptr; |
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244 | register JDIMENSION col; |
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245 | |||
246 | ptr = source->pub.buffer[0]; |
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247 | for (col = cinfo->image_width; col > 0; col--) { |
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248 | (*source->read_pixel) (source); /* Load next pixel into tga_pixel */ |
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249 | *ptr++ = (JSAMPLE) UCH(source->tga_pixel[2]); /* change BGR to RGB order */ |
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250 | *ptr++ = (JSAMPLE) UCH(source->tga_pixel[1]); |
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251 | *ptr++ = (JSAMPLE) UCH(source->tga_pixel[0]); |
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252 | } |
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253 | return 1; |
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254 | } |
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255 | |||
256 | /* |
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257 | * Targa also defines a 32-bit pixel format with order B,G,R,A. |
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258 | * We presently ignore the attribute byte, so the code for reading |
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259 | * these pixels is identical to the 24-bit routine above. |
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260 | * This works because the actual pixel length is only known to read_pixel. |
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261 | */ |
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262 | |||
263 | #define get_32bit_row get_24bit_row |
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264 | |||
265 | |||
266 | /* |
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267 | * This method is for re-reading the input data in standard top-down |
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268 | * row order. The entire image has already been read into whole_image |
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269 | * with proper conversion of pixel format, but it's in a funny row order. |
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270 | */ |
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271 | |||
272 | METHODDEF(JDIMENSION) |
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273 | get_memory_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
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274 | { |
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275 | tga_source_ptr source = (tga_source_ptr) sinfo; |
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276 | JDIMENSION source_row; |
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277 | |||
278 | /* Compute row of source that maps to current_row of normal order */ |
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279 | /* For now, assume image is bottom-up and not interlaced. */ |
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280 | /* NEEDS WORK to support interlaced images! */ |
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281 | source_row = cinfo->image_height - source->current_row - 1; |
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282 | |||
283 | /* Fetch that row from virtual array */ |
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284 | source->pub.buffer = (*cinfo->mem->access_virt_sarray) |
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285 | ((j_common_ptr) cinfo, source->whole_image, |
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286 | source_row, (JDIMENSION) 1, FALSE); |
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287 | |||
288 | source->current_row++; |
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289 | return 1; |
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290 | } |
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291 | |||
292 | |||
293 | /* |
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294 | * This method loads the image into whole_image during the first call on |
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295 | * get_pixel_rows. The get_pixel_rows pointer is then adjusted to call |
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296 | * get_memory_row on subsequent calls. |
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297 | */ |
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298 | |||
299 | METHODDEF(JDIMENSION) |
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300 | preload_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
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301 | { |
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302 | tga_source_ptr source = (tga_source_ptr) sinfo; |
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303 | JDIMENSION row; |
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304 | cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress; |
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305 | |||
306 | /* Read the data into a virtual array in input-file row order. */ |
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307 | for (row = 0; row < cinfo->image_height; row++) { |
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308 | if (progress != NULL) { |
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309 | progress->pub.pass_counter = (long) row; |
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310 | progress->pub.pass_limit = (long) cinfo->image_height; |
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311 | (*progress->pub.progress_monitor) ((j_common_ptr) cinfo); |
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312 | } |
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313 | source->pub.buffer = (*cinfo->mem->access_virt_sarray) |
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314 | ((j_common_ptr) cinfo, source->whole_image, row, (JDIMENSION) 1, TRUE); |
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315 | (*source->get_pixel_rows) (cinfo, sinfo); |
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316 | } |
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317 | if (progress != NULL) |
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318 | progress->completed_extra_passes++; |
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319 | |||
320 | /* Set up to read from the virtual array in unscrambled order */ |
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321 | source->pub.get_pixel_rows = get_memory_row; |
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322 | source->current_row = 0; |
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323 | /* And read the first row */ |
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324 | return get_memory_row(cinfo, sinfo); |
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325 | } |
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326 | |||
327 | |||
328 | /* |
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329 | * Read the file header; return image size and component count. |
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330 | */ |
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331 | |||
332 | METHODDEF(void) |
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333 | start_input_tga (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
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334 | { |
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335 | tga_source_ptr source = (tga_source_ptr) sinfo; |
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336 | U_CHAR targaheader[18]; |
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337 | int idlen, cmaptype, subtype, flags, interlace_type, components; |
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338 | unsigned int width, height, maplen; |
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339 | boolean is_bottom_up; |
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340 | |||
341 | #define GET_2B(offset) ((unsigned int) UCH(targaheader[offset]) + \ |
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342 | (((unsigned int) UCH(targaheader[offset+1])) << 8)) |
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343 | |||
344 | if (! ReadOK(source->pub.input_file, targaheader, 18)) |
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345 | ERREXIT(cinfo, JERR_INPUT_EOF); |
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346 | |||
347 | /* Pretend "15-bit" pixels are 16-bit --- we ignore attribute bit anyway */ |
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348 | if (targaheader[16] == 15) |
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349 | targaheader[16] = 16; |
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350 | |||
351 | idlen = UCH(targaheader[0]); |
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352 | cmaptype = UCH(targaheader[1]); |
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353 | subtype = UCH(targaheader[2]); |
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354 | maplen = GET_2B(5); |
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355 | width = GET_2B(12); |
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356 | height = GET_2B(14); |
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357 | source->pixel_size = UCH(targaheader[16]) >> 3; |
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358 | flags = UCH(targaheader[17]); /* Image Descriptor byte */ |
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359 | |||
360 | is_bottom_up = ((flags & 0x20) == 0); /* bit 5 set => top-down */ |
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361 | interlace_type = flags >> 6; /* bits 6/7 are interlace code */ |
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362 | |||
363 | if (cmaptype > 1 || /* cmaptype must be 0 or 1 */ |
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364 | source->pixel_size < 1 || source->pixel_size > 4 || |
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365 | (UCH(targaheader[16]) & 7) != 0 || /* bits/pixel must be multiple of 8 */ |
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366 | interlace_type != 0) /* currently don't allow interlaced image */ |
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367 | ERREXIT(cinfo, JERR_TGA_BADPARMS); |
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368 | |||
369 | if (subtype > 8) { |
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370 | /* It's an RLE-coded file */ |
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371 | source->read_pixel = read_rle_pixel; |
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372 | source->block_count = source->dup_pixel_count = 0; |
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373 | subtype -= 8; |
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374 | } else { |
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375 | /* Non-RLE file */ |
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376 | source->read_pixel = read_non_rle_pixel; |
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377 | } |
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378 | |||
379 | /* Now should have subtype 1, 2, or 3 */ |
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380 | components = 3; /* until proven different */ |
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381 | cinfo->in_color_space = JCS_RGB; |
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382 | |||
383 | switch (subtype) { |
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384 | case 1: /* Colormapped image */ |
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385 | if (source->pixel_size == 1 && cmaptype == 1) |
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386 | source->get_pixel_rows = get_8bit_row; |
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387 | else |
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388 | ERREXIT(cinfo, JERR_TGA_BADPARMS); |
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389 | TRACEMS2(cinfo, 1, JTRC_TGA_MAPPED, width, height); |
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390 | break; |
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391 | case 2: /* RGB image */ |
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392 | switch (source->pixel_size) { |
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393 | case 2: |
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394 | source->get_pixel_rows = get_16bit_row; |
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395 | break; |
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396 | case 3: |
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397 | source->get_pixel_rows = get_24bit_row; |
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398 | break; |
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399 | case 4: |
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400 | source->get_pixel_rows = get_32bit_row; |
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401 | break; |
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402 | default: |
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403 | ERREXIT(cinfo, JERR_TGA_BADPARMS); |
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404 | break; |
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405 | } |
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406 | TRACEMS2(cinfo, 1, JTRC_TGA, width, height); |
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407 | break; |
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408 | case 3: /* Grayscale image */ |
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409 | components = 1; |
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410 | cinfo->in_color_space = JCS_GRAYSCALE; |
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411 | if (source->pixel_size == 1) |
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412 | source->get_pixel_rows = get_8bit_gray_row; |
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413 | else |
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414 | ERREXIT(cinfo, JERR_TGA_BADPARMS); |
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415 | TRACEMS2(cinfo, 1, JTRC_TGA_GRAY, width, height); |
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416 | break; |
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417 | default: |
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418 | ERREXIT(cinfo, JERR_TGA_BADPARMS); |
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419 | break; |
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420 | } |
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421 | |||
422 | if (is_bottom_up) { |
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423 | /* Create a virtual array to buffer the upside-down image. */ |
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424 | source->whole_image = (*cinfo->mem->request_virt_sarray) |
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425 | ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE, |
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426 | (JDIMENSION) width * components, (JDIMENSION) height, (JDIMENSION) 1); |
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427 | if (cinfo->progress != NULL) { |
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428 | cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress; |
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429 | progress->total_extra_passes++; /* count file input as separate pass */ |
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430 | } |
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431 | /* source->pub.buffer will point to the virtual array. */ |
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432 | source->pub.buffer_height = 1; /* in case anyone looks at it */ |
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433 | source->pub.get_pixel_rows = preload_image; |
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434 | } else { |
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435 | /* Don't need a virtual array, but do need a one-row input buffer. */ |
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436 | source->whole_image = NULL; |
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437 | source->pub.buffer = (*cinfo->mem->alloc_sarray) |
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438 | ((j_common_ptr) cinfo, JPOOL_IMAGE, |
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439 | (JDIMENSION) width * components, (JDIMENSION) 1); |
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440 | source->pub.buffer_height = 1; |
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441 | source->pub.get_pixel_rows = source->get_pixel_rows; |
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442 | } |
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443 | |||
444 | while (idlen--) /* Throw away ID field */ |
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445 | (void) read_byte(source); |
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446 | |||
447 | if (maplen > 0) { |
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448 | if (maplen > 256 || GET_2B(3) != 0) |
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449 | ERREXIT(cinfo, JERR_TGA_BADCMAP); |
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450 | /* Allocate space to store the colormap */ |
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451 | source->colormap = (*cinfo->mem->alloc_sarray) |
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452 | ((j_common_ptr) cinfo, JPOOL_IMAGE, (JDIMENSION) maplen, (JDIMENSION) 3); |
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453 | /* and read it from the file */ |
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454 | read_colormap(source, (int) maplen, UCH(targaheader[7])); |
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455 | } else { |
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456 | if (cmaptype) /* but you promised a cmap! */ |
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457 | ERREXIT(cinfo, JERR_TGA_BADPARMS); |
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458 | source->colormap = NULL; |
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459 | } |
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460 | |||
461 | cinfo->input_components = components; |
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462 | cinfo->data_precision = 8; |
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463 | cinfo->image_width = width; |
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464 | cinfo->image_height = height; |
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465 | } |
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466 | |||
467 | |||
468 | /* |
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469 | * Finish up at the end of the file. |
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470 | */ |
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471 | |||
472 | METHODDEF(void) |
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473 | finish_input_tga (j_compress_ptr cinfo, cjpeg_source_ptr sinfo) |
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474 | { |
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475 | /* no work */ |
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476 | } |
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477 | |||
478 | |||
479 | /* |
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480 | * The module selection routine for Targa format input. |
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481 | */ |
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482 | |||
483 | GLOBAL(cjpeg_source_ptr) |
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484 | jinit_read_targa (j_compress_ptr cinfo) |
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485 | { |
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486 | tga_source_ptr source; |
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487 | |||
488 | /* Create module interface object */ |
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489 | source = (tga_source_ptr) |
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490 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
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491 | SIZEOF(tga_source_struct)); |
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492 | source->cinfo = cinfo; /* make back link for subroutines */ |
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493 | /* Fill in method ptrs, except get_pixel_rows which start_input sets */ |
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494 | source->pub.start_input = start_input_tga; |
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495 | source->pub.finish_input = finish_input_tga; |
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496 | |||
497 | return (cjpeg_source_ptr) source; |
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498 | } |
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499 | |||
500 | #endif /* TARGA_SUPPORTED */>><>>><>>>>> |