From 62cdc4181f536384c70254f1e5d8ab311cff368d Mon Sep 17 00:00:00 2001 From: Tavian Barnes Date: Sun, 10 May 2009 04:19:07 +0000 Subject: Merge libdimension-png into libdimension. --- libdimension/Makefile.am | 6 +- libdimension/dimension.h | 1 + libdimension/dimension/png.h | 43 ++++++ libdimension/png.c | 328 +++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 375 insertions(+), 3 deletions(-) create mode 100644 libdimension/dimension/png.h create mode 100644 libdimension/png.c (limited to 'libdimension') diff --git a/libdimension/Makefile.am b/libdimension/Makefile.am index ee3b6dc..7114b04 100644 --- a/libdimension/Makefile.am +++ b/libdimension/Makefile.am @@ -17,10 +17,10 @@ ## along with this program. If not, see . ## ########################################################################### -nobase_include_HEADERS = dimension.h dimension/array.h dimension/canvas.h dimension/color.h dimension/error.h dimension/geometry.h +nobase_include_HEADERS = dimension.h dimension/array.h dimension/canvas.h dimension/color.h dimension/error.h dimension/geometry.h dimension/png.h lib_LTLIBRARIES = libdimension.la -libdimension_la_SOURCES = $(nobase_include_HEADERS) array.c canvas.c color.c error.c geometry.c +libdimension_la_SOURCES = $(nobase_include_HEADERS) array.c canvas.c color.c error.c geometry.c png.c libdimension_la_LDFLAGS = -version-info 0:0:0 -libdimension_la_LIBADD = -lm -lpthread +libdimension_la_LIBADD = -lm -lpthread -lpng diff --git a/libdimension/dimension.h b/libdimension/dimension.h index ac65f4c..50e1544 100644 --- a/libdimension/dimension.h +++ b/libdimension/dimension.h @@ -32,6 +32,7 @@ extern "C" { #include #include #include +#include #ifdef __cplusplus } diff --git a/libdimension/dimension/png.h b/libdimension/dimension/png.h new file mode 100644 index 0000000..9ee55c3 --- /dev/null +++ b/libdimension/dimension/png.h @@ -0,0 +1,43 @@ +/************************************************************************* + * Copyright (C) 2008 Tavian Barnes * + * * + * This file is part of The Dimension Library. * + * * + * The Dimension Library is free software; you can redistribute it and/ * + * or modify it under the terms of the GNU Lesser General Public License * + * as published by the Free Software Foundation; either version 3 of the * + * License, or (at your option) any later version. * + * * + * The Dimension Library is distributed in the hope that it will be * + * useful, but WITHOUT ANY WARRANTY; without even the implied warranty * + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * + * Lesser General Public License for more details. * + * * + * You should have received a copy of the GNU Lesser General Public * + * License along with this program. If not, see * + * . * + *************************************************************************/ + +#ifndef DIMENSION_PNG_H +#define DIMENSION_PNG_H + +#include +#include + +#ifdef __cplusplus +/* We've been included from a C++ file; mark everything here as extern "C" */ +extern "C" { +#endif + +/* Write canvas to file in PNG format. Returns 0 on success, nonzero on + failure */ +int dmnsn_png_write_canvas(const dmnsn_canvas *canvas, FILE *file); + +/* Read a canvas from a PNG file. Returns NULL on failure. */ +dmnsn_canvas *dmnsn_png_read_canvas(FILE *file); + +#ifdef __cplusplus +} +#endif + +#endif /* DIMENSION_PNG_H */ diff --git a/libdimension/png.c b/libdimension/png.c new file mode 100644 index 0000000..5f45011 --- /dev/null +++ b/libdimension/png.c @@ -0,0 +1,328 @@ +/************************************************************************* + * Copyright (C) 2008 Tavian Barnes * + * * + * This file is part of The Dimension Library. * + * * + * The Dimension Library is free software; you can redistribute it and/ * + * or modify it under the terms of the GNU Lesser General Public License * + * as published by the Free Software Foundation; either version 3 of the * + * License, or (at your option) any later version. * + * * + * The Dimension Library is distributed in the hope that it will be * + * useful, but WITHOUT ANY WARRANTY; without even the implied warranty * + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * + * Lesser General Public License for more details. * + * * + * You should have received a copy of the GNU Lesser General Public * + * License along with this program. If not, see * + * . * + *************************************************************************/ + +#include "dimension.h" +#include +#include +#include +#include + +/* Write a canvas to a png file, using libpng. Return 0 on success, nonzero on + failure. */ +int +dmnsn_png_write_canvas(const dmnsn_canvas *canvas, FILE *file) +{ + png_structp png_ptr; + png_infop info_ptr; + png_uint_32 width, height; + unsigned int x, y; + uint16_t *row = NULL; + dmnsn_color color; + dmnsn_sRGB sRGB; + + if (!file) return 1; /* file was NULL */ + + width = canvas->x; + height = canvas->y; + + png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); + if (!png_ptr) return 1; /* Couldn't create libpng write struct */ + + info_ptr = png_create_info_struct(png_ptr); + if (!info_ptr) { + /* Couldn't create libpng info struct */ + png_destroy_write_struct(&png_ptr, NULL); + return 1; + } + + /* libpng will longjmp here if it encounters an error from here on */ + if (setjmp(png_jmpbuf(png_ptr))) { + /* libpng error */ + if (row) free(row); + png_destroy_write_struct(&png_ptr, &info_ptr); + return 1; + } + + /* Associate file with the libpng write struct */ + png_init_io(png_ptr, file); + + /* Set header correctly for 16-bit sRGB image */ + png_set_IHDR(png_ptr, info_ptr, width, height, 16, + PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE, + PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT); + png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, PNG_sRGB_INTENT_ABSOLUTE); + + /* We think of transparency in the opposite way that PNG does */ + png_set_invert_alpha(png_ptr); + + /* Write the info struct */ + png_write_info(png_ptr, info_ptr); + + if (htonl(1) != 1) { + /* We are little-endian; swap the byte order of the pixels */ + png_set_swap(png_ptr); + } + + /* Allocate the temporary row of RGBA values */ + row = malloc(4*sizeof(uint16_t)*width); + if (!row) { + png_destroy_write_struct(&png_ptr, &info_ptr); + return 1; + } + + /* Write the pixels */ + for (y = 0; y < height; ++y) { + for (x = 0; x < width; ++x) { + /* Invert the rows. PNG coordinates are fourth quadrant. */ + color = dmnsn_get_pixel(canvas, x, height - y - 1); + sRGB = dmnsn_sRGB_from_color(color); + + /* Saturate R, G, and B to [0, UINT16_MAX] */ + + if (sRGB.R <= 0.0) { + row[4*x] = 0; + } else if (sRGB.R >= 1.0) { + row[4*x] = UINT16_MAX; + } else { + row[4*x] = sRGB.R*UINT16_MAX; + } + + if (sRGB.G <= 0.0) { + row[4*x + 1] = 0; + } else if (sRGB.G >= 1.0) { + row[4*x + 1] = UINT16_MAX; + } else { + row[4*x + 1] = sRGB.G*UINT16_MAX; + } + + if (sRGB.B <= 0.0) { + row[4*x + 2] = 0; + } else if (sRGB.B >= 1.0) { + row[4*x + 2] = UINT16_MAX; + } else { + row[4*x + 2] = sRGB.B*UINT16_MAX; + } + + /* color.filter + color.trans is in [0.0, 1.0] by definition */ + row[4*x + 3] = (color.filter + color.trans)*UINT16_MAX; + } + + /* Write the row */ + png_write_row(png_ptr, (png_bytep)row); + } + + /* Finish the PNG file */ + png_write_end(png_ptr, info_ptr); + + free(row); + png_destroy_write_struct(&png_ptr, &info_ptr); + return 0; +} + +/* Read a canvas from the PNG file `file'. Return NULL on error. */ +dmnsn_canvas * +dmnsn_png_read_canvas(FILE *file) +{ + dmnsn_canvas *canvas; + png_byte header[8] = { 0, 0, 0, 0, 0, 0, 0, 0 }; + png_structp png_ptr; + png_infop info_ptr; + png_uint_32 width, height, rowbytes; + int bit_depth, color_type, interlace_type, compression_type, filter_method; + png_bytep image = NULL; + png_bytep *row_pointers = NULL; + unsigned int x, y; + dmnsn_color color; + dmnsn_sRGB sRGB; + png_bytep png_pixel; + + if (!file) return NULL; /* file was NULL */ + + fread(header, 1, 8, file); + if (png_sig_cmp(header, 0, 8)) return NULL; /* file is not a PNG file */ + + /* Create the libpng read struct */ + png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); + if (!png_ptr) return NULL; + + /* Create the libpng info struct */ + info_ptr = png_create_info_struct(png_ptr); + if (!info_ptr) { + png_destroy_read_struct(&png_ptr, NULL, NULL); + return NULL; + } + + /* libpng will longjmp here if it encounters an error from here on */ + if (setjmp(png_jmpbuf(png_ptr))) { + /* libpng error */ + if (row_pointers) free(row_pointers); + if (image) free(image); + png_destroy_read_struct(&png_ptr, &info_ptr, NULL); + return NULL; + } + + /* Associate the read struct with the file, and tell it we've already checked + 8 bytes of signature */ + png_init_io(png_ptr, file); + png_set_sig_bytes(png_ptr, 8); + + /* Read the PNG header into info struct */ + png_read_info(png_ptr, info_ptr); + + /* Get useful information from the info struct */ + png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, + &interlace_type, &compression_type, &filter_method); + + /* + * - Convert paletted images to RGB. + * - Convert a tRNS chunk to an alpha channel + * - Convert grayscale to RGB + * - Invert the alpha channel + */ + if (color_type == PNG_COLOR_TYPE_PALETTE) { + png_set_palette_to_rgb(png_ptr); + } + if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) { + png_set_tRNS_to_alpha(png_ptr); + } + if (color_type == PNG_COLOR_TYPE_GRAY + || color_type == PNG_COLOR_TYPE_GRAY_ALPHA) { + png_set_gray_to_rgb(png_ptr); + } + png_set_invert_alpha(png_ptr); + + /* Update the info struct */ + png_read_update_info(png_ptr, info_ptr); + + /* Get bytes/image row */ + rowbytes = png_get_rowbytes(png_ptr, info_ptr); + + /* Allocate the temporary image buffer */ + image = malloc(rowbytes*height); + if (!image) { + png_destroy_read_struct(&png_ptr, &info_ptr, NULL); + return NULL; + } + + /* Allocate and set an array of pointers to rows in image */ + + row_pointers = malloc(sizeof(png_bytep)*height); + if (!row_pointers) { + free(image); + png_destroy_read_struct(&png_ptr, &info_ptr, NULL); + return NULL; + } + + for (y = 0; y < height; ++y) { + row_pointers[y] = image + y*rowbytes; + } + + /* Read the image to image all at once. At the expense of greater memory use, + this handles interlacing for us. */ + png_read_image(png_ptr, row_pointers); + + /* Allocate the canvas */ + canvas = dmnsn_new_canvas(width, height); + if (!canvas) { + free(row_pointers); + free(image); + png_read_end(png_ptr, NULL); + png_destroy_read_struct(&png_ptr, &info_ptr, NULL); + return NULL; + } + + /* Now we convert the image to our canvas format. This depends on the image + bit depth (which has been scaled up to at least 8 or 16), and the presence + of an alpha channel. For performance reasons, the tests are outside the + loops, although that doesn't really matter for a decent compiler. */ + if (bit_depth == 16) { + if (color_type & PNG_COLOR_MASK_ALPHA) { + for (x = 0; x < width; ++x) { + for (y = 0; y < height; ++y) { + png_pixel = image + 8*(y*width + x); + + sRGB.R = ((double)((png_pixel[0] << UINT16_C(8)) + png_pixel[1])) + /UINT16_MAX; + sRGB.G = ((double)((png_pixel[2] << UINT16_C(8)) + png_pixel[3])) + /UINT16_MAX; + sRGB.B = ((double)((png_pixel[4] << UINT16_C(8)) + png_pixel[5])) + /UINT16_MAX; + + color = dmnsn_color_from_sRGB(sRGB); + color.trans = ((double)((png_pixel[6] << UINT16_C(8)) + + png_pixel[7]))/UINT16_MAX; + dmnsn_set_pixel(canvas, x, height - y - 1, color); + } + } + } else { + for (x = 0; x < width; ++x) { + for (y = 0; y < height; ++y) { + png_pixel = image + 6*(y*width + x); + + sRGB.R = ((double)((png_pixel[0] << UINT16_C(8)) + png_pixel[1])) + /UINT16_MAX; + sRGB.G = ((double)((png_pixel[2] << UINT16_C(8)) + png_pixel[3])) + /UINT16_MAX; + sRGB.B = ((double)((png_pixel[4] << UINT16_C(8)) + png_pixel[5])) + /UINT16_MAX; + + color = dmnsn_color_from_sRGB(sRGB); + dmnsn_set_pixel(canvas, x, height - y - 1, color); + } + } + } + } else { + /* Bit depth is 8 */ + if (color_type & PNG_COLOR_MASK_ALPHA) { + for (x = 0; x < width; ++x) { + for (y = 0; y < height; ++y) { + png_pixel = image + 4*(y*width + x); + + sRGB.R = ((double)png_pixel[0])/UINT8_MAX; + sRGB.G = ((double)png_pixel[1])/UINT8_MAX; + sRGB.B = ((double)png_pixel[2])/UINT8_MAX; + + color = dmnsn_color_from_sRGB(sRGB); + color.trans = ((double)png_pixel[3])/UINT8_MAX; + dmnsn_set_pixel(canvas, x, height - y - 1, color); + } + } + } else { + for (x = 0; x < width; ++x) { + for (y = 0; y < height; ++y) { + png_pixel = image + 3*(y*width + x); + + sRGB.R = ((double)png_pixel[0])/UINT8_MAX; + sRGB.G = ((double)png_pixel[1])/UINT8_MAX; + sRGB.B = ((double)png_pixel[2])/UINT8_MAX; + + color = dmnsn_color_from_sRGB(sRGB); + dmnsn_set_pixel(canvas, x, height - y - 1, color); + } + } + } + } + + free(row_pointers); + free(image); + png_read_end(png_ptr, NULL); + png_destroy_read_struct(&png_ptr, &info_ptr, NULL); + return canvas; +} -- cgit v1.2.3