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1 |
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2 /* png.c - location for general purpose libpng functions |
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3 * |
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4 * Last changed in libpng 1.2.39 [August 13, 2009] |
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5 * Copyright (c) 1998-2009 Glenn Randers-Pehrson |
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6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
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7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
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8 * |
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9 * This code is released under the libpng license. |
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10 * For conditions of distribution and use, see the disclaimer |
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11 * and license in png.h |
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12 */ |
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13 |
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14 #define PNG_INTERNAL |
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15 #define PNG_NO_EXTERN |
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16 #include "png.h" |
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17 |
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18 /* Generate a compiler error if there is an old png.h in the search path. */ |
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19 typedef version_1_2_40 Your_png_h_is_not_version_1_2_40; |
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20 |
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21 /* Version information for C files. This had better match the version |
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22 * string defined in png.h. */ |
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23 |
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24 #ifdef PNG_USE_GLOBAL_ARRAYS |
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25 /* png_libpng_ver was changed to a function in version 1.0.5c */ |
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26 PNG_CONST char png_libpng_ver[18] = PNG_LIBPNG_VER_STRING; |
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27 |
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28 #ifdef PNG_READ_SUPPORTED |
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29 |
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30 /* png_sig was changed to a function in version 1.0.5c */ |
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31 /* Place to hold the signature string for a PNG file. */ |
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32 PNG_CONST png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10}; |
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33 #endif /* PNG_READ_SUPPORTED */ |
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34 |
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35 /* Invoke global declarations for constant strings for known chunk types */ |
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36 PNG_IHDR; |
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37 PNG_IDAT; |
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38 PNG_IEND; |
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39 PNG_PLTE; |
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40 PNG_bKGD; |
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41 PNG_cHRM; |
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42 PNG_gAMA; |
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43 PNG_hIST; |
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44 PNG_iCCP; |
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45 PNG_iTXt; |
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46 PNG_oFFs; |
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47 PNG_pCAL; |
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48 PNG_sCAL; |
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49 PNG_pHYs; |
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50 PNG_sBIT; |
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51 PNG_sPLT; |
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52 PNG_sRGB; |
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53 PNG_tEXt; |
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54 PNG_tIME; |
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55 PNG_tRNS; |
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56 PNG_zTXt; |
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57 |
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58 #ifdef PNG_READ_SUPPORTED |
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59 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
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60 |
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61 /* Start of interlace block */ |
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62 PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; |
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63 |
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64 /* Offset to next interlace block */ |
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65 PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; |
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66 |
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67 /* Start of interlace block in the y direction */ |
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68 PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; |
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69 |
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70 /* Offset to next interlace block in the y direction */ |
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71 PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; |
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72 |
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73 /* Height of interlace block. This is not currently used - if you need |
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74 * it, uncomment it here and in png.h |
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75 PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; |
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76 */ |
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77 |
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78 /* Mask to determine which pixels are valid in a pass */ |
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79 PNG_CONST int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff}; |
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80 |
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81 /* Mask to determine which pixels to overwrite while displaying */ |
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82 PNG_CONST int FARDATA png_pass_dsp_mask[] |
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83 = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; |
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84 |
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85 #endif /* PNG_READ_SUPPORTED */ |
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86 #endif /* PNG_USE_GLOBAL_ARRAYS */ |
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87 |
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88 /* Tells libpng that we have already handled the first "num_bytes" bytes |
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89 * of the PNG file signature. If the PNG data is embedded into another |
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90 * stream we can set num_bytes = 8 so that libpng will not attempt to read |
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91 * or write any of the magic bytes before it starts on the IHDR. |
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92 */ |
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93 |
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94 #ifdef PNG_READ_SUPPORTED |
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95 void PNGAPI |
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96 png_set_sig_bytes(png_structp png_ptr, int num_bytes) |
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97 { |
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98 if (png_ptr == NULL) |
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99 return; |
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100 png_debug(1, "in png_set_sig_bytes"); |
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101 if (num_bytes > 8) |
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102 png_error(png_ptr, "Too many bytes for PNG signature."); |
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103 |
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104 png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes); |
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105 } |
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106 |
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107 /* Checks whether the supplied bytes match the PNG signature. We allow |
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108 * checking less than the full 8-byte signature so that those apps that |
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109 * already read the first few bytes of a file to determine the file type |
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110 * can simply check the remaining bytes for extra assurance. Returns |
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111 * an integer less than, equal to, or greater than zero if sig is found, |
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112 * respectively, to be less than, to match, or be greater than the correct |
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113 * PNG signature (this is the same behaviour as strcmp, memcmp, etc). |
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114 */ |
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115 int PNGAPI |
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116 png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check) |
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117 { |
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118 png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; |
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119 if (num_to_check > 8) |
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120 num_to_check = 8; |
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121 else if (num_to_check < 1) |
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122 return (-1); |
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123 |
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124 if (start > 7) |
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125 return (-1); |
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126 |
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127 if (start + num_to_check > 8) |
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128 num_to_check = 8 - start; |
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129 |
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130 return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check))); |
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131 } |
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132 |
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133 #if defined(PNG_1_0_X) || defined(PNG_1_2_X) |
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134 /* (Obsolete) function to check signature bytes. It does not allow one |
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135 * to check a partial signature. This function might be removed in the |
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136 * future - use png_sig_cmp(). Returns true (nonzero) if the file is PNG. |
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137 */ |
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138 int PNGAPI |
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139 png_check_sig(png_bytep sig, int num) |
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140 { |
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141 return ((int)!png_sig_cmp(sig, (png_size_t)0, (png_size_t)num)); |
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142 } |
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143 #endif |
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144 #endif /* PNG_READ_SUPPORTED */ |
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145 |
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146 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) |
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147 /* Function to allocate memory for zlib and clear it to 0. */ |
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148 #ifdef PNG_1_0_X |
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149 voidpf PNGAPI |
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150 #else |
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151 voidpf /* PRIVATE */ |
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152 #endif |
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153 png_zalloc(voidpf png_ptr, uInt items, uInt size) |
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154 { |
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155 png_voidp ptr; |
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156 png_structp p=(png_structp)png_ptr; |
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157 png_uint_32 save_flags=p->flags; |
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158 png_uint_32 num_bytes; |
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159 |
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160 if (png_ptr == NULL) |
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161 return (NULL); |
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162 if (items > PNG_UINT_32_MAX/size) |
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163 { |
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164 png_warning (p, "Potential overflow in png_zalloc()"); |
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165 return (NULL); |
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166 } |
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167 num_bytes = (png_uint_32)items * size; |
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168 |
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169 p->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK; |
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170 ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes); |
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171 p->flags=save_flags; |
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172 |
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173 #if defined(PNG_1_0_X) && !defined(PNG_NO_ZALLOC_ZERO) |
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174 if (ptr == NULL) |
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175 return ((voidpf)ptr); |
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176 |
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177 if (num_bytes > (png_uint_32)0x8000L) |
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178 { |
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179 png_memset(ptr, 0, (png_size_t)0x8000L); |
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180 png_memset((png_bytep)ptr + (png_size_t)0x8000L, 0, |
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181 (png_size_t)(num_bytes - (png_uint_32)0x8000L)); |
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182 } |
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183 else |
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184 { |
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185 png_memset(ptr, 0, (png_size_t)num_bytes); |
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186 } |
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187 #endif |
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188 return ((voidpf)ptr); |
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189 } |
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190 |
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191 /* Function to free memory for zlib */ |
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192 #ifdef PNG_1_0_X |
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193 void PNGAPI |
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194 #else |
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195 void /* PRIVATE */ |
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196 #endif |
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197 png_zfree(voidpf png_ptr, voidpf ptr) |
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198 { |
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199 png_free((png_structp)png_ptr, (png_voidp)ptr); |
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200 } |
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201 |
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202 /* Reset the CRC variable to 32 bits of 1's. Care must be taken |
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203 * in case CRC is > 32 bits to leave the top bits 0. |
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204 */ |
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205 void /* PRIVATE */ |
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206 png_reset_crc(png_structp png_ptr) |
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207 { |
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208 png_ptr->crc = crc32(0, Z_NULL, 0); |
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209 } |
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210 |
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211 /* Calculate the CRC over a section of data. We can only pass as |
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212 * much data to this routine as the largest single buffer size. We |
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213 * also check that this data will actually be used before going to the |
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214 * trouble of calculating it. |
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215 */ |
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216 void /* PRIVATE */ |
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217 png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length) |
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218 { |
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219 int need_crc = 1; |
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220 |
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221 if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ |
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222 { |
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223 if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == |
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224 (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) |
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225 need_crc = 0; |
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226 } |
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227 else /* critical */ |
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228 { |
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229 if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) |
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230 need_crc = 0; |
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231 } |
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232 |
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233 if (need_crc) |
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234 png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length); |
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235 } |
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236 |
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237 /* Allocate the memory for an info_struct for the application. We don't |
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238 * really need the png_ptr, but it could potentially be useful in the |
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239 * future. This should be used in favour of malloc(png_sizeof(png_info)) |
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240 * and png_info_init() so that applications that want to use a shared |
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241 * libpng don't have to be recompiled if png_info changes size. |
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242 */ |
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243 png_infop PNGAPI |
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244 png_create_info_struct(png_structp png_ptr) |
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245 { |
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246 png_infop info_ptr; |
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247 |
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248 png_debug(1, "in png_create_info_struct"); |
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249 if (png_ptr == NULL) |
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250 return (NULL); |
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251 #ifdef PNG_USER_MEM_SUPPORTED |
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252 info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO, |
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253 png_ptr->malloc_fn, png_ptr->mem_ptr); |
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254 #else |
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255 info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO); |
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256 #endif |
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257 if (info_ptr != NULL) |
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258 png_info_init_3(&info_ptr, png_sizeof(png_info)); |
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259 |
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260 return (info_ptr); |
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261 } |
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262 |
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263 /* This function frees the memory associated with a single info struct. |
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264 * Normally, one would use either png_destroy_read_struct() or |
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265 * png_destroy_write_struct() to free an info struct, but this may be |
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266 * useful for some applications. |
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267 */ |
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268 void PNGAPI |
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269 png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr) |
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270 { |
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271 png_infop info_ptr = NULL; |
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272 if (png_ptr == NULL) |
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273 return; |
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274 |
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275 png_debug(1, "in png_destroy_info_struct"); |
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276 if (info_ptr_ptr != NULL) |
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277 info_ptr = *info_ptr_ptr; |
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278 |
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279 if (info_ptr != NULL) |
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280 { |
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281 png_info_destroy(png_ptr, info_ptr); |
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282 |
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283 #ifdef PNG_USER_MEM_SUPPORTED |
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284 png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn, |
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285 png_ptr->mem_ptr); |
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286 #else |
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287 png_destroy_struct((png_voidp)info_ptr); |
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288 #endif |
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289 *info_ptr_ptr = NULL; |
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290 } |
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291 } |
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292 |
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293 /* Initialize the info structure. This is now an internal function (0.89) |
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294 * and applications using it are urged to use png_create_info_struct() |
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295 * instead. |
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296 */ |
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297 #if defined(PNG_1_0_X) || defined(PNG_1_2_X) |
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298 #undef png_info_init |
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299 void PNGAPI |
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300 png_info_init(png_infop info_ptr) |
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301 { |
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302 /* We only come here via pre-1.0.12-compiled applications */ |
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303 png_info_init_3(&info_ptr, 0); |
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304 } |
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305 #endif |
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306 |
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307 void PNGAPI |
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308 png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size) |
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309 { |
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310 png_infop info_ptr = *ptr_ptr; |
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311 |
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312 if (info_ptr == NULL) |
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313 return; |
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314 |
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315 png_debug(1, "in png_info_init_3"); |
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316 |
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317 if (png_sizeof(png_info) > png_info_struct_size) |
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318 { |
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319 png_destroy_struct(info_ptr); |
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320 info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO); |
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321 *ptr_ptr = info_ptr; |
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322 } |
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323 |
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324 /* Set everything to 0 */ |
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325 png_memset(info_ptr, 0, png_sizeof(png_info)); |
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326 } |
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327 |
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328 #ifdef PNG_FREE_ME_SUPPORTED |
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329 void PNGAPI |
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330 png_data_freer(png_structp png_ptr, png_infop info_ptr, |
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331 int freer, png_uint_32 mask) |
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332 { |
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333 png_debug(1, "in png_data_freer"); |
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334 if (png_ptr == NULL || info_ptr == NULL) |
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335 return; |
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336 if (freer == PNG_DESTROY_WILL_FREE_DATA) |
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337 info_ptr->free_me |= mask; |
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338 else if (freer == PNG_USER_WILL_FREE_DATA) |
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339 info_ptr->free_me &= ~mask; |
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340 else |
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341 png_warning(png_ptr, |
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342 "Unknown freer parameter in png_data_freer."); |
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343 } |
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344 #endif |
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345 |
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346 void PNGAPI |
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347 png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask, |
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348 int num) |
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349 { |
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350 png_debug(1, "in png_free_data"); |
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351 if (png_ptr == NULL || info_ptr == NULL) |
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352 return; |
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353 |
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354 #if defined(PNG_TEXT_SUPPORTED) |
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355 /* Free text item num or (if num == -1) all text items */ |
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356 #ifdef PNG_FREE_ME_SUPPORTED |
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357 if ((mask & PNG_FREE_TEXT) & info_ptr->free_me) |
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358 #else |
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359 if (mask & PNG_FREE_TEXT) |
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360 #endif |
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361 { |
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362 if (num != -1) |
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363 { |
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364 if (info_ptr->text && info_ptr->text[num].key) |
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365 { |
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366 png_free(png_ptr, info_ptr->text[num].key); |
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367 info_ptr->text[num].key = NULL; |
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368 } |
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369 } |
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370 else |
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371 { |
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372 int i; |
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373 for (i = 0; i < info_ptr->num_text; i++) |
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374 png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i); |
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375 png_free(png_ptr, info_ptr->text); |
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376 info_ptr->text = NULL; |
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377 info_ptr->num_text=0; |
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378 } |
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379 } |
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380 #endif |
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381 |
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382 #if defined(PNG_tRNS_SUPPORTED) |
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383 /* Free any tRNS entry */ |
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384 #ifdef PNG_FREE_ME_SUPPORTED |
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385 if ((mask & PNG_FREE_TRNS) & info_ptr->free_me) |
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386 #else |
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387 if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS)) |
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388 #endif |
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389 { |
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390 png_free(png_ptr, info_ptr->trans); |
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391 info_ptr->trans = NULL; |
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392 info_ptr->valid &= ~PNG_INFO_tRNS; |
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393 #ifndef PNG_FREE_ME_SUPPORTED |
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394 png_ptr->flags &= ~PNG_FLAG_FREE_TRNS; |
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395 #endif |
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396 } |
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397 #endif |
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398 |
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399 #if defined(PNG_sCAL_SUPPORTED) |
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400 /* Free any sCAL entry */ |
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401 #ifdef PNG_FREE_ME_SUPPORTED |
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402 if ((mask & PNG_FREE_SCAL) & info_ptr->free_me) |
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403 #else |
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404 if (mask & PNG_FREE_SCAL) |
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405 #endif |
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406 { |
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407 #if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) |
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408 png_free(png_ptr, info_ptr->scal_s_width); |
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409 png_free(png_ptr, info_ptr->scal_s_height); |
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410 info_ptr->scal_s_width = NULL; |
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411 info_ptr->scal_s_height = NULL; |
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412 #endif |
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413 info_ptr->valid &= ~PNG_INFO_sCAL; |
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414 } |
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415 #endif |
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416 |
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417 #if defined(PNG_pCAL_SUPPORTED) |
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418 /* Free any pCAL entry */ |
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419 #ifdef PNG_FREE_ME_SUPPORTED |
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420 if ((mask & PNG_FREE_PCAL) & info_ptr->free_me) |
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421 #else |
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422 if (mask & PNG_FREE_PCAL) |
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423 #endif |
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424 { |
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425 png_free(png_ptr, info_ptr->pcal_purpose); |
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426 png_free(png_ptr, info_ptr->pcal_units); |
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427 info_ptr->pcal_purpose = NULL; |
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428 info_ptr->pcal_units = NULL; |
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429 if (info_ptr->pcal_params != NULL) |
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430 { |
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431 int i; |
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432 for (i = 0; i < (int)info_ptr->pcal_nparams; i++) |
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433 { |
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434 png_free(png_ptr, info_ptr->pcal_params[i]); |
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435 info_ptr->pcal_params[i]=NULL; |
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436 } |
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437 png_free(png_ptr, info_ptr->pcal_params); |
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438 info_ptr->pcal_params = NULL; |
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439 } |
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440 info_ptr->valid &= ~PNG_INFO_pCAL; |
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441 } |
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442 #endif |
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443 |
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444 #if defined(PNG_iCCP_SUPPORTED) |
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445 /* Free any iCCP entry */ |
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446 #ifdef PNG_FREE_ME_SUPPORTED |
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447 if ((mask & PNG_FREE_ICCP) & info_ptr->free_me) |
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448 #else |
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449 if (mask & PNG_FREE_ICCP) |
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450 #endif |
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451 { |
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452 png_free(png_ptr, info_ptr->iccp_name); |
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453 png_free(png_ptr, info_ptr->iccp_profile); |
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454 info_ptr->iccp_name = NULL; |
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455 info_ptr->iccp_profile = NULL; |
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456 info_ptr->valid &= ~PNG_INFO_iCCP; |
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457 } |
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458 #endif |
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459 |
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460 #if defined(PNG_sPLT_SUPPORTED) |
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461 /* Free a given sPLT entry, or (if num == -1) all sPLT entries */ |
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462 #ifdef PNG_FREE_ME_SUPPORTED |
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463 if ((mask & PNG_FREE_SPLT) & info_ptr->free_me) |
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464 #else |
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465 if (mask & PNG_FREE_SPLT) |
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466 #endif |
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467 { |
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468 if (num != -1) |
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469 { |
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470 if (info_ptr->splt_palettes) |
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471 { |
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472 png_free(png_ptr, info_ptr->splt_palettes[num].name); |
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473 png_free(png_ptr, info_ptr->splt_palettes[num].entries); |
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474 info_ptr->splt_palettes[num].name = NULL; |
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475 info_ptr->splt_palettes[num].entries = NULL; |
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476 } |
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477 } |
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478 else |
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479 { |
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480 if (info_ptr->splt_palettes_num) |
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481 { |
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482 int i; |
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483 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++) |
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484 png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i); |
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485 |
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486 png_free(png_ptr, info_ptr->splt_palettes); |
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487 info_ptr->splt_palettes = NULL; |
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488 info_ptr->splt_palettes_num = 0; |
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489 } |
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490 info_ptr->valid &= ~PNG_INFO_sPLT; |
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491 } |
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492 } |
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493 #endif |
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494 |
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495 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) |
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496 if (png_ptr->unknown_chunk.data) |
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497 { |
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498 png_free(png_ptr, png_ptr->unknown_chunk.data); |
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499 png_ptr->unknown_chunk.data = NULL; |
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500 } |
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501 |
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502 #ifdef PNG_FREE_ME_SUPPORTED |
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503 if ((mask & PNG_FREE_UNKN) & info_ptr->free_me) |
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504 #else |
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505 if (mask & PNG_FREE_UNKN) |
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506 #endif |
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507 { |
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508 if (num != -1) |
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509 { |
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510 if (info_ptr->unknown_chunks) |
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511 { |
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512 png_free(png_ptr, info_ptr->unknown_chunks[num].data); |
|
513 info_ptr->unknown_chunks[num].data = NULL; |
|
514 } |
|
515 } |
|
516 else |
|
517 { |
|
518 int i; |
|
519 |
|
520 if (info_ptr->unknown_chunks_num) |
|
521 { |
|
522 for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++) |
|
523 png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i); |
|
524 |
|
525 png_free(png_ptr, info_ptr->unknown_chunks); |
|
526 info_ptr->unknown_chunks = NULL; |
|
527 info_ptr->unknown_chunks_num = 0; |
|
528 } |
|
529 } |
|
530 } |
|
531 #endif |
|
532 |
|
533 #if defined(PNG_hIST_SUPPORTED) |
|
534 /* Free any hIST entry */ |
|
535 #ifdef PNG_FREE_ME_SUPPORTED |
|
536 if ((mask & PNG_FREE_HIST) & info_ptr->free_me) |
|
537 #else |
|
538 if ((mask & PNG_FREE_HIST) && (png_ptr->flags & PNG_FLAG_FREE_HIST)) |
|
539 #endif |
|
540 { |
|
541 png_free(png_ptr, info_ptr->hist); |
|
542 info_ptr->hist = NULL; |
|
543 info_ptr->valid &= ~PNG_INFO_hIST; |
|
544 #ifndef PNG_FREE_ME_SUPPORTED |
|
545 png_ptr->flags &= ~PNG_FLAG_FREE_HIST; |
|
546 #endif |
|
547 } |
|
548 #endif |
|
549 |
|
550 /* Free any PLTE entry that was internally allocated */ |
|
551 #ifdef PNG_FREE_ME_SUPPORTED |
|
552 if ((mask & PNG_FREE_PLTE) & info_ptr->free_me) |
|
553 #else |
|
554 if ((mask & PNG_FREE_PLTE) && (png_ptr->flags & PNG_FLAG_FREE_PLTE)) |
|
555 #endif |
|
556 { |
|
557 png_zfree(png_ptr, info_ptr->palette); |
|
558 info_ptr->palette = NULL; |
|
559 info_ptr->valid &= ~PNG_INFO_PLTE; |
|
560 #ifndef PNG_FREE_ME_SUPPORTED |
|
561 png_ptr->flags &= ~PNG_FLAG_FREE_PLTE; |
|
562 #endif |
|
563 info_ptr->num_palette = 0; |
|
564 } |
|
565 |
|
566 #if defined(PNG_INFO_IMAGE_SUPPORTED) |
|
567 /* Free any image bits attached to the info structure */ |
|
568 #ifdef PNG_FREE_ME_SUPPORTED |
|
569 if ((mask & PNG_FREE_ROWS) & info_ptr->free_me) |
|
570 #else |
|
571 if (mask & PNG_FREE_ROWS) |
|
572 #endif |
|
573 { |
|
574 if (info_ptr->row_pointers) |
|
575 { |
|
576 int row; |
|
577 for (row = 0; row < (int)info_ptr->height; row++) |
|
578 { |
|
579 png_free(png_ptr, info_ptr->row_pointers[row]); |
|
580 info_ptr->row_pointers[row]=NULL; |
|
581 } |
|
582 png_free(png_ptr, info_ptr->row_pointers); |
|
583 info_ptr->row_pointers=NULL; |
|
584 } |
|
585 info_ptr->valid &= ~PNG_INFO_IDAT; |
|
586 } |
|
587 #endif |
|
588 |
|
589 #ifdef PNG_FREE_ME_SUPPORTED |
|
590 if (num == -1) |
|
591 info_ptr->free_me &= ~mask; |
|
592 else |
|
593 info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL); |
|
594 #endif |
|
595 } |
|
596 |
|
597 /* This is an internal routine to free any memory that the info struct is |
|
598 * pointing to before re-using it or freeing the struct itself. Recall |
|
599 * that png_free() checks for NULL pointers for us. |
|
600 */ |
|
601 void /* PRIVATE */ |
|
602 png_info_destroy(png_structp png_ptr, png_infop info_ptr) |
|
603 { |
|
604 png_debug(1, "in png_info_destroy"); |
|
605 |
|
606 png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1); |
|
607 |
|
608 #if defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED) |
|
609 if (png_ptr->num_chunk_list) |
|
610 { |
|
611 png_free(png_ptr, png_ptr->chunk_list); |
|
612 png_ptr->chunk_list=NULL; |
|
613 png_ptr->num_chunk_list = 0; |
|
614 } |
|
615 #endif |
|
616 |
|
617 png_info_init_3(&info_ptr, png_sizeof(png_info)); |
|
618 } |
|
619 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */ |
|
620 |
|
621 /* This function returns a pointer to the io_ptr associated with the user |
|
622 * functions. The application should free any memory associated with this |
|
623 * pointer before png_write_destroy() or png_read_destroy() are called. |
|
624 */ |
|
625 png_voidp PNGAPI |
|
626 png_get_io_ptr(png_structp png_ptr) |
|
627 { |
|
628 if (png_ptr == NULL) |
|
629 return (NULL); |
|
630 return (png_ptr->io_ptr); |
|
631 } |
|
632 |
|
633 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) |
|
634 #if !defined(PNG_NO_STDIO) |
|
635 /* Initialize the default input/output functions for the PNG file. If you |
|
636 * use your own read or write routines, you can call either png_set_read_fn() |
|
637 * or png_set_write_fn() instead of png_init_io(). If you have defined |
|
638 * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't |
|
639 * necessarily available. |
|
640 */ |
|
641 void PNGAPI |
|
642 png_init_io(png_structp png_ptr, png_FILE_p fp) |
|
643 { |
|
644 png_debug(1, "in png_init_io"); |
|
645 if (png_ptr == NULL) |
|
646 return; |
|
647 png_ptr->io_ptr = (png_voidp)fp; |
|
648 } |
|
649 #endif |
|
650 |
|
651 #if defined(PNG_TIME_RFC1123_SUPPORTED) |
|
652 /* Convert the supplied time into an RFC 1123 string suitable for use in |
|
653 * a "Creation Time" or other text-based time string. |
|
654 */ |
|
655 png_charp PNGAPI |
|
656 png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime) |
|
657 { |
|
658 static PNG_CONST char short_months[12][4] = |
|
659 {"Jan", "Feb", "Mar", "Apr", "May", "Jun", |
|
660 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}; |
|
661 |
|
662 if (png_ptr == NULL) |
|
663 return (NULL); |
|
664 if (png_ptr->time_buffer == NULL) |
|
665 { |
|
666 png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29* |
|
667 png_sizeof(char))); |
|
668 } |
|
669 |
|
670 #if defined(_WIN32_WCE) |
|
671 { |
|
672 wchar_t time_buf[29]; |
|
673 wsprintf(time_buf, TEXT("%d %S %d %02d:%02d:%02d +0000"), |
|
674 ptime->day % 32, short_months[(ptime->month - 1) % 12], |
|
675 ptime->year, ptime->hour % 24, ptime->minute % 60, |
|
676 ptime->second % 61); |
|
677 WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer, 29, |
|
678 NULL, NULL); |
|
679 } |
|
680 #else |
|
681 #ifdef USE_FAR_KEYWORD |
|
682 { |
|
683 char near_time_buf[29]; |
|
684 png_snprintf6(near_time_buf, 29, "%d %s %d %02d:%02d:%02d +0000", |
|
685 ptime->day % 32, short_months[(ptime->month - 1) % 12], |
|
686 ptime->year, ptime->hour % 24, ptime->minute % 60, |
|
687 ptime->second % 61); |
|
688 png_memcpy(png_ptr->time_buffer, near_time_buf, |
|
689 29*png_sizeof(char)); |
|
690 } |
|
691 #else |
|
692 png_snprintf6(png_ptr->time_buffer, 29, "%d %s %d %02d:%02d:%02d +0000", |
|
693 ptime->day % 32, short_months[(ptime->month - 1) % 12], |
|
694 ptime->year, ptime->hour % 24, ptime->minute % 60, |
|
695 ptime->second % 61); |
|
696 #endif |
|
697 #endif /* _WIN32_WCE */ |
|
698 return ((png_charp)png_ptr->time_buffer); |
|
699 } |
|
700 #endif /* PNG_TIME_RFC1123_SUPPORTED */ |
|
701 |
|
702 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */ |
|
703 |
|
704 png_charp PNGAPI |
|
705 png_get_copyright(png_structp png_ptr) |
|
706 { |
|
707 png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */ |
|
708 return ((png_charp) "\n libpng version 1.2.40 - September 10, 2009\n\ |
|
709 Copyright (c) 1998-2009 Glenn Randers-Pehrson\n\ |
|
710 Copyright (c) 1996-1997 Andreas Dilger\n\ |
|
711 Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.\n"); |
|
712 } |
|
713 |
|
714 /* The following return the library version as a short string in the |
|
715 * format 1.0.0 through 99.99.99zz. To get the version of *.h files |
|
716 * used with your application, print out PNG_LIBPNG_VER_STRING, which |
|
717 * is defined in png.h. |
|
718 * Note: now there is no difference between png_get_libpng_ver() and |
|
719 * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard, |
|
720 * it is guaranteed that png.c uses the correct version of png.h. |
|
721 */ |
|
722 png_charp PNGAPI |
|
723 png_get_libpng_ver(png_structp png_ptr) |
|
724 { |
|
725 /* Version of *.c files used when building libpng */ |
|
726 png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */ |
|
727 return ((png_charp) PNG_LIBPNG_VER_STRING); |
|
728 } |
|
729 |
|
730 png_charp PNGAPI |
|
731 png_get_header_ver(png_structp png_ptr) |
|
732 { |
|
733 /* Version of *.h files used when building libpng */ |
|
734 png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */ |
|
735 return ((png_charp) PNG_LIBPNG_VER_STRING); |
|
736 } |
|
737 |
|
738 png_charp PNGAPI |
|
739 png_get_header_version(png_structp png_ptr) |
|
740 { |
|
741 /* Returns longer string containing both version and date */ |
|
742 png_ptr = png_ptr; /* Silence compiler warning about unused png_ptr */ |
|
743 return ((png_charp) PNG_HEADER_VERSION_STRING |
|
744 #ifndef PNG_READ_SUPPORTED |
|
745 " (NO READ SUPPORT)" |
|
746 #endif |
|
747 "\n"); |
|
748 } |
|
749 |
|
750 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) |
|
751 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED |
|
752 int PNGAPI |
|
753 png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name) |
|
754 { |
|
755 /* Check chunk_name and return "keep" value if it's on the list, else 0 */ |
|
756 int i; |
|
757 png_bytep p; |
|
758 if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list<=0) |
|
759 return 0; |
|
760 p = png_ptr->chunk_list + png_ptr->num_chunk_list*5 - 5; |
|
761 for (i = png_ptr->num_chunk_list; i; i--, p -= 5) |
|
762 if (!png_memcmp(chunk_name, p, 4)) |
|
763 return ((int)*(p + 4)); |
|
764 return 0; |
|
765 } |
|
766 #endif |
|
767 |
|
768 /* This function, added to libpng-1.0.6g, is untested. */ |
|
769 int PNGAPI |
|
770 png_reset_zstream(png_structp png_ptr) |
|
771 { |
|
772 if (png_ptr == NULL) |
|
773 return Z_STREAM_ERROR; |
|
774 return (inflateReset(&png_ptr->zstream)); |
|
775 } |
|
776 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */ |
|
777 |
|
778 /* This function was added to libpng-1.0.7 */ |
|
779 png_uint_32 PNGAPI |
|
780 png_access_version_number(void) |
|
781 { |
|
782 /* Version of *.c files used when building libpng */ |
|
783 return((png_uint_32) PNG_LIBPNG_VER); |
|
784 } |
|
785 |
|
786 |
|
787 #if defined(PNG_READ_SUPPORTED) && defined(PNG_ASSEMBLER_CODE_SUPPORTED) |
|
788 #if !defined(PNG_1_0_X) |
|
789 /* This function was added to libpng 1.2.0 */ |
|
790 int PNGAPI |
|
791 png_mmx_support(void) |
|
792 { |
|
793 /* Obsolete, to be removed from libpng-1.4.0 */ |
|
794 return -1; |
|
795 } |
|
796 #endif /* PNG_1_0_X */ |
|
797 #endif /* PNG_READ_SUPPORTED && PNG_ASSEMBLER_CODE_SUPPORTED */ |
|
798 |
|
799 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) |
|
800 #ifdef PNG_SIZE_T |
|
801 /* Added at libpng version 1.2.6 */ |
|
802 PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size)); |
|
803 png_size_t PNGAPI |
|
804 png_convert_size(size_t size) |
|
805 { |
|
806 if (size > (png_size_t)-1) |
|
807 PNG_ABORT(); /* We haven't got access to png_ptr, so no png_error() */ |
|
808 return ((png_size_t)size); |
|
809 } |
|
810 #endif /* PNG_SIZE_T */ |
|
811 |
|
812 /* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */ |
|
813 #if defined(PNG_cHRM_SUPPORTED) |
|
814 #if !defined(PNG_NO_CHECK_cHRM) |
|
815 |
|
816 /* |
|
817 * Multiply two 32-bit numbers, V1 and V2, using 32-bit |
|
818 * arithmetic, to produce a 64 bit result in the HI/LO words. |
|
819 * |
|
820 * A B |
|
821 * x C D |
|
822 * ------ |
|
823 * AD || BD |
|
824 * AC || CB || 0 |
|
825 * |
|
826 * where A and B are the high and low 16-bit words of V1, |
|
827 * C and D are the 16-bit words of V2, AD is the product of |
|
828 * A and D, and X || Y is (X << 16) + Y. |
|
829 */ |
|
830 |
|
831 void /* PRIVATE */ |
|
832 png_64bit_product (long v1, long v2, unsigned long *hi_product, |
|
833 unsigned long *lo_product) |
|
834 { |
|
835 int a, b, c, d; |
|
836 long lo, hi, x, y; |
|
837 |
|
838 a = (v1 >> 16) & 0xffff; |
|
839 b = v1 & 0xffff; |
|
840 c = (v2 >> 16) & 0xffff; |
|
841 d = v2 & 0xffff; |
|
842 |
|
843 lo = b * d; /* BD */ |
|
844 x = a * d + c * b; /* AD + CB */ |
|
845 y = ((lo >> 16) & 0xffff) + x; |
|
846 |
|
847 lo = (lo & 0xffff) | ((y & 0xffff) << 16); |
|
848 hi = (y >> 16) & 0xffff; |
|
849 |
|
850 hi += a * c; /* AC */ |
|
851 |
|
852 *hi_product = (unsigned long)hi; |
|
853 *lo_product = (unsigned long)lo; |
|
854 } |
|
855 |
|
856 int /* PRIVATE */ |
|
857 png_check_cHRM_fixed(png_structp png_ptr, |
|
858 png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x, |
|
859 png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y, |
|
860 png_fixed_point blue_x, png_fixed_point blue_y) |
|
861 { |
|
862 int ret = 1; |
|
863 unsigned long xy_hi,xy_lo,yx_hi,yx_lo; |
|
864 |
|
865 png_debug(1, "in function png_check_cHRM_fixed"); |
|
866 if (png_ptr == NULL) |
|
867 return 0; |
|
868 |
|
869 if (white_x < 0 || white_y <= 0 || |
|
870 red_x < 0 || red_y < 0 || |
|
871 green_x < 0 || green_y < 0 || |
|
872 blue_x < 0 || blue_y < 0) |
|
873 { |
|
874 png_warning(png_ptr, |
|
875 "Ignoring attempt to set negative chromaticity value"); |
|
876 ret = 0; |
|
877 } |
|
878 if (white_x > (png_fixed_point) PNG_UINT_31_MAX || |
|
879 white_y > (png_fixed_point) PNG_UINT_31_MAX || |
|
880 red_x > (png_fixed_point) PNG_UINT_31_MAX || |
|
881 red_y > (png_fixed_point) PNG_UINT_31_MAX || |
|
882 green_x > (png_fixed_point) PNG_UINT_31_MAX || |
|
883 green_y > (png_fixed_point) PNG_UINT_31_MAX || |
|
884 blue_x > (png_fixed_point) PNG_UINT_31_MAX || |
|
885 blue_y > (png_fixed_point) PNG_UINT_31_MAX ) |
|
886 { |
|
887 png_warning(png_ptr, |
|
888 "Ignoring attempt to set chromaticity value exceeding 21474.83"); |
|
889 ret = 0; |
|
890 } |
|
891 if (white_x > 100000L - white_y) |
|
892 { |
|
893 png_warning(png_ptr, "Invalid cHRM white point"); |
|
894 ret = 0; |
|
895 } |
|
896 if (red_x > 100000L - red_y) |
|
897 { |
|
898 png_warning(png_ptr, "Invalid cHRM red point"); |
|
899 ret = 0; |
|
900 } |
|
901 if (green_x > 100000L - green_y) |
|
902 { |
|
903 png_warning(png_ptr, "Invalid cHRM green point"); |
|
904 ret = 0; |
|
905 } |
|
906 if (blue_x > 100000L - blue_y) |
|
907 { |
|
908 png_warning(png_ptr, "Invalid cHRM blue point"); |
|
909 ret = 0; |
|
910 } |
|
911 |
|
912 png_64bit_product(green_x - red_x, blue_y - red_y, &xy_hi, &xy_lo); |
|
913 png_64bit_product(green_y - red_y, blue_x - red_x, &yx_hi, &yx_lo); |
|
914 |
|
915 if (xy_hi == yx_hi && xy_lo == yx_lo) |
|
916 { |
|
917 png_warning(png_ptr, |
|
918 "Ignoring attempt to set cHRM RGB triangle with zero area"); |
|
919 ret = 0; |
|
920 } |
|
921 |
|
922 return ret; |
|
923 } |
|
924 #endif /* NO_PNG_CHECK_cHRM */ |
|
925 #endif /* PNG_cHRM_SUPPORTED */ |
|
926 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */ |