--- /dev/null
+\r
+/* pngwtran.c - transforms the data in a row for PNG writers\r
+ *\r
+ * Last changed in libpng 1.2.9 April 14, 2006\r
+ * For conditions of distribution and use, see copyright notice in png.h\r
+ * Copyright (c) 1998-2006 Glenn Randers-Pehrson\r
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)\r
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)\r
+ */\r
+\r
+#define PNG_INTERNAL\r
+#include "png.h"\r
+#ifdef PNG_WRITE_SUPPORTED\r
+\r
+/* Transform the data according to the user's wishes. The order of\r
+ * transformations is significant.\r
+ */\r
+void /* PRIVATE */\r
+png_do_write_transformations(png_structp png_ptr)\r
+{\r
+ png_debug(1, "in png_do_write_transformations\n");\r
+\r
+ if (png_ptr == NULL)\r
+ return;\r
+\r
+#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_USER_TRANSFORM)\r
+ if (png_ptr->write_user_transform_fn != NULL)\r
+ (*(png_ptr->write_user_transform_fn)) /* user write transform function */\r
+ (png_ptr, /* png_ptr */\r
+ &(png_ptr->row_info), /* row_info: */\r
+ /* png_uint_32 width; width of row */\r
+ /* png_uint_32 rowbytes; number of bytes in row */\r
+ /* png_byte color_type; color type of pixels */\r
+ /* png_byte bit_depth; bit depth of samples */\r
+ /* png_byte channels; number of channels (1-4) */\r
+ /* png_byte pixel_depth; bits per pixel (depth*channels) */\r
+ png_ptr->row_buf + 1); /* start of pixel data for row */\r
+#endif\r
+#if defined(PNG_WRITE_FILLER_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_FILLER)\r
+ png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,\r
+ png_ptr->flags);\r
+#endif\r
+#if defined(PNG_WRITE_PACKSWAP_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_PACKSWAP)\r
+ png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+#if defined(PNG_WRITE_PACK_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_PACK)\r
+ png_do_pack(&(png_ptr->row_info), png_ptr->row_buf + 1,\r
+ (png_uint_32)png_ptr->bit_depth);\r
+#endif\r
+#if defined(PNG_WRITE_SWAP_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_SWAP_BYTES)\r
+ png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+#if defined(PNG_WRITE_SHIFT_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_SHIFT)\r
+ png_do_shift(&(png_ptr->row_info), png_ptr->row_buf + 1,\r
+ &(png_ptr->shift));\r
+#endif\r
+#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_SWAP_ALPHA)\r
+ png_do_write_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_INVERT_ALPHA)\r
+ png_do_write_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+#if defined(PNG_WRITE_BGR_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_BGR)\r
+ png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+#if defined(PNG_WRITE_INVERT_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_INVERT_MONO)\r
+ png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+}\r
+\r
+#if defined(PNG_WRITE_PACK_SUPPORTED)\r
+/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The\r
+ * row_info bit depth should be 8 (one pixel per byte). The channels\r
+ * should be 1 (this only happens on grayscale and paletted images).\r
+ */\r
+void /* PRIVATE */\r
+png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)\r
+{\r
+ png_debug(1, "in png_do_pack\n");\r
+ if (row_info->bit_depth == 8 &&\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ row != NULL && row_info != NULL &&\r
+#endif\r
+ row_info->channels == 1)\r
+ {\r
+ switch ((int)bit_depth)\r
+ {\r
+ case 1:\r
+ {\r
+ png_bytep sp, dp;\r
+ int mask, v;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ sp = row;\r
+ dp = row;\r
+ mask = 0x80;\r
+ v = 0;\r
+\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ if (*sp != 0)\r
+ v |= mask;\r
+ sp++;\r
+ if (mask > 1)\r
+ mask >>= 1;\r
+ else\r
+ {\r
+ mask = 0x80;\r
+ *dp = (png_byte)v;\r
+ dp++;\r
+ v = 0;\r
+ }\r
+ }\r
+ if (mask != 0x80)\r
+ *dp = (png_byte)v;\r
+ break;\r
+ }\r
+ case 2:\r
+ {\r
+ png_bytep sp, dp;\r
+ int shift, v;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ sp = row;\r
+ dp = row;\r
+ shift = 6;\r
+ v = 0;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ png_byte value;\r
+\r
+ value = (png_byte)(*sp & 0x03);\r
+ v |= (value << shift);\r
+ if (shift == 0)\r
+ {\r
+ shift = 6;\r
+ *dp = (png_byte)v;\r
+ dp++;\r
+ v = 0;\r
+ }\r
+ else\r
+ shift -= 2;\r
+ sp++;\r
+ }\r
+ if (shift != 6)\r
+ *dp = (png_byte)v;\r
+ break;\r
+ }\r
+ case 4:\r
+ {\r
+ png_bytep sp, dp;\r
+ int shift, v;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ sp = row;\r
+ dp = row;\r
+ shift = 4;\r
+ v = 0;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ png_byte value;\r
+\r
+ value = (png_byte)(*sp & 0x0f);\r
+ v |= (value << shift);\r
+\r
+ if (shift == 0)\r
+ {\r
+ shift = 4;\r
+ *dp = (png_byte)v;\r
+ dp++;\r
+ v = 0;\r
+ }\r
+ else\r
+ shift -= 4;\r
+\r
+ sp++;\r
+ }\r
+ if (shift != 4)\r
+ *dp = (png_byte)v;\r
+ break;\r
+ }\r
+ }\r
+ row_info->bit_depth = (png_byte)bit_depth;\r
+ row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);\r
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,\r
+ row_info->width);\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_SHIFT_SUPPORTED)\r
+/* Shift pixel values to take advantage of whole range. Pass the\r
+ * true number of bits in bit_depth. The row should be packed\r
+ * according to row_info->bit_depth. Thus, if you had a row of\r
+ * bit depth 4, but the pixels only had values from 0 to 7, you\r
+ * would pass 3 as bit_depth, and this routine would translate the\r
+ * data to 0 to 15.\r
+ */\r
+void /* PRIVATE */\r
+png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth)\r
+{\r
+ png_debug(1, "in png_do_shift\n");\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ if (row != NULL && row_info != NULL &&\r
+#else\r
+ if (\r
+#endif\r
+ row_info->color_type != PNG_COLOR_TYPE_PALETTE)\r
+ {\r
+ int shift_start[4], shift_dec[4];\r
+ int channels = 0;\r
+\r
+ if (row_info->color_type & PNG_COLOR_MASK_COLOR)\r
+ {\r
+ shift_start[channels] = row_info->bit_depth - bit_depth->red;\r
+ shift_dec[channels] = bit_depth->red;\r
+ channels++;\r
+ shift_start[channels] = row_info->bit_depth - bit_depth->green;\r
+ shift_dec[channels] = bit_depth->green;\r
+ channels++;\r
+ shift_start[channels] = row_info->bit_depth - bit_depth->blue;\r
+ shift_dec[channels] = bit_depth->blue;\r
+ channels++;\r
+ }\r
+ else\r
+ {\r
+ shift_start[channels] = row_info->bit_depth - bit_depth->gray;\r
+ shift_dec[channels] = bit_depth->gray;\r
+ channels++;\r
+ }\r
+ if (row_info->color_type & PNG_COLOR_MASK_ALPHA)\r
+ {\r
+ shift_start[channels] = row_info->bit_depth - bit_depth->alpha;\r
+ shift_dec[channels] = bit_depth->alpha;\r
+ channels++;\r
+ }\r
+\r
+ /* with low row depths, could only be grayscale, so one channel */\r
+ if (row_info->bit_depth < 8)\r
+ {\r
+ png_bytep bp = row;\r
+ png_uint_32 i;\r
+ png_byte mask;\r
+ png_uint_32 row_bytes = row_info->rowbytes;\r
+\r
+ if (bit_depth->gray == 1 && row_info->bit_depth == 2)\r
+ mask = 0x55;\r
+ else if (row_info->bit_depth == 4 && bit_depth->gray == 3)\r
+ mask = 0x11;\r
+ else\r
+ mask = 0xff;\r
+\r
+ for (i = 0; i < row_bytes; i++, bp++)\r
+ {\r
+ png_uint_16 v;\r
+ int j;\r
+\r
+ v = *bp;\r
+ *bp = 0;\r
+ for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])\r
+ {\r
+ if (j > 0)\r
+ *bp |= (png_byte)((v << j) & 0xff);\r
+ else\r
+ *bp |= (png_byte)((v >> (-j)) & mask);\r
+ }\r
+ }\r
+ }\r
+ else if (row_info->bit_depth == 8)\r
+ {\r
+ png_bytep bp = row;\r
+ png_uint_32 i;\r
+ png_uint_32 istop = channels * row_info->width;\r
+\r
+ for (i = 0; i < istop; i++, bp++)\r
+ {\r
+\r
+ png_uint_16 v;\r
+ int j;\r
+ int c = (int)(i%channels);\r
+\r
+ v = *bp;\r
+ *bp = 0;\r
+ for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])\r
+ {\r
+ if (j > 0)\r
+ *bp |= (png_byte)((v << j) & 0xff);\r
+ else\r
+ *bp |= (png_byte)((v >> (-j)) & 0xff);\r
+ }\r
+ }\r
+ }\r
+ else\r
+ {\r
+ png_bytep bp;\r
+ png_uint_32 i;\r
+ png_uint_32 istop = channels * row_info->width;\r
+\r
+ for (bp = row, i = 0; i < istop; i++)\r
+ {\r
+ int c = (int)(i%channels);\r
+ png_uint_16 value, v;\r
+ int j;\r
+\r
+ v = (png_uint_16)(((png_uint_16)(*bp) << 8) + *(bp + 1));\r
+ value = 0;\r
+ for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])\r
+ {\r
+ if (j > 0)\r
+ value |= (png_uint_16)((v << j) & (png_uint_16)0xffff);\r
+ else\r
+ value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff);\r
+ }\r
+ *bp++ = (png_byte)(value >> 8);\r
+ *bp++ = (png_byte)(value & 0xff);\r
+ }\r
+ }\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)\r
+void /* PRIVATE */\r
+png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)\r
+{\r
+ png_debug(1, "in png_do_write_swap_alpha\n");\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ if (row != NULL && row_info != NULL)\r
+#endif\r
+ {\r
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)\r
+ {\r
+ /* This converts from ARGB to RGBA */\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ png_bytep sp, dp;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+ for (i = 0, sp = dp = row; i < row_width; i++)\r
+ {\r
+ png_byte save = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = save;\r
+ }\r
+ }\r
+ /* This converts from AARRGGBB to RRGGBBAA */\r
+ else\r
+ {\r
+ png_bytep sp, dp;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ for (i = 0, sp = dp = row; i < row_width; i++)\r
+ {\r
+ png_byte save[2];\r
+ save[0] = *(sp++);\r
+ save[1] = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = save[0];\r
+ *(dp++) = save[1];\r
+ }\r
+ }\r
+ }\r
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)\r
+ {\r
+ /* This converts from AG to GA */\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ png_bytep sp, dp;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ for (i = 0, sp = dp = row; i < row_width; i++)\r
+ {\r
+ png_byte save = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = save;\r
+ }\r
+ }\r
+ /* This converts from AAGG to GGAA */\r
+ else\r
+ {\r
+ png_bytep sp, dp;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ for (i = 0, sp = dp = row; i < row_width; i++)\r
+ {\r
+ png_byte save[2];\r
+ save[0] = *(sp++);\r
+ save[1] = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = save[0];\r
+ *(dp++) = save[1];\r
+ }\r
+ }\r
+ }\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)\r
+void /* PRIVATE */\r
+png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)\r
+{\r
+ png_debug(1, "in png_do_write_invert_alpha\n");\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ if (row != NULL && row_info != NULL)\r
+#endif\r
+ {\r
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)\r
+ {\r
+ /* This inverts the alpha channel in RGBA */\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ png_bytep sp, dp;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+ for (i = 0, sp = dp = row; i < row_width; i++)\r
+ {\r
+ /* does nothing\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ */\r
+ sp+=3; dp = sp;\r
+ *(dp++) = (png_byte)(255 - *(sp++));\r
+ }\r
+ }\r
+ /* This inverts the alpha channel in RRGGBBAA */\r
+ else\r
+ {\r
+ png_bytep sp, dp;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ for (i = 0, sp = dp = row; i < row_width; i++)\r
+ {\r
+ /* does nothing\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ */\r
+ sp+=6; dp = sp;\r
+ *(dp++) = (png_byte)(255 - *(sp++));\r
+ *(dp++) = (png_byte)(255 - *(sp++));\r
+ }\r
+ }\r
+ }\r
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)\r
+ {\r
+ /* This inverts the alpha channel in GA */\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ png_bytep sp, dp;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ for (i = 0, sp = dp = row; i < row_width; i++)\r
+ {\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = (png_byte)(255 - *(sp++));\r
+ }\r
+ }\r
+ /* This inverts the alpha channel in GGAA */\r
+ else\r
+ {\r
+ png_bytep sp, dp;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ for (i = 0, sp = dp = row; i < row_width; i++)\r
+ {\r
+ /* does nothing\r
+ *(dp++) = *(sp++);\r
+ *(dp++) = *(sp++);\r
+ */\r
+ sp+=2; dp = sp;\r
+ *(dp++) = (png_byte)(255 - *(sp++));\r
+ *(dp++) = (png_byte)(255 - *(sp++));\r
+ }\r
+ }\r
+ }\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_MNG_FEATURES_SUPPORTED)\r
+/* undoes intrapixel differencing */\r
+void /* PRIVATE */\r
+png_do_write_intrapixel(png_row_infop row_info, png_bytep row)\r
+{\r
+ png_debug(1, "in png_do_write_intrapixel\n");\r
+ if (\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ row != NULL && row_info != NULL &&\r
+#endif\r
+ (row_info->color_type & PNG_COLOR_MASK_COLOR))\r
+ {\r
+ int bytes_per_pixel;\r
+ png_uint_32 row_width = row_info->width;\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ png_bytep rp;\r
+ png_uint_32 i;\r
+\r
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)\r
+ bytes_per_pixel = 3;\r
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)\r
+ bytes_per_pixel = 4;\r
+ else\r
+ return;\r
+\r
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)\r
+ {\r
+ *(rp) = (png_byte)((*rp - *(rp+1))&0xff);\r
+ *(rp+2) = (png_byte)((*(rp+2) - *(rp+1))&0xff);\r
+ }\r
+ }\r
+ else if (row_info->bit_depth == 16)\r
+ {\r
+ png_bytep rp;\r
+ png_uint_32 i;\r
+\r
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)\r
+ bytes_per_pixel = 6;\r
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)\r
+ bytes_per_pixel = 8;\r
+ else\r
+ return;\r
+\r
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)\r
+ {\r
+ png_uint_32 s0 = (*(rp ) << 8) | *(rp+1);\r
+ png_uint_32 s1 = (*(rp+2) << 8) | *(rp+3);\r
+ png_uint_32 s2 = (*(rp+4) << 8) | *(rp+5);\r
+ png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL);\r
+ png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);\r
+ *(rp ) = (png_byte)((red >> 8) & 0xff);\r
+ *(rp+1) = (png_byte)(red & 0xff);\r
+ *(rp+4) = (png_byte)((blue >> 8) & 0xff);\r
+ *(rp+5) = (png_byte)(blue & 0xff);\r
+ }\r
+ }\r
+ }\r
+}\r
+#endif /* PNG_MNG_FEATURES_SUPPORTED */\r
+#endif /* PNG_WRITE_SUPPORTED */\r
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