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/* $Id$ */
/*
* This file is part of OpenTTD.
* OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
* OpenTTD 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 General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file png.cpp Reading sprites from png files. */
#ifdef WITH_PNG
#include "../stdafx.h"
#include "../fileio_func.h"
#include "../debug.h"
#include "png.hpp"
#include <png.h>
#define PNG_SLOT 62
static void PNGAPI png_my_read(png_structp png_ptr, png_bytep data, png_size_t length)
{
FioReadBlock(data, length);
}
static void PNGAPI png_my_error(png_structp png_ptr, png_const_charp message)
{
DEBUG(sprite, 0, "ERROR (libpng): %s - %s", message, (char *)png_get_error_ptr(png_ptr));
longjmp(png_jmpbuf(png_ptr), 1);
}
static void PNGAPI png_my_warning(png_structp png_ptr, png_const_charp message)
{
DEBUG(sprite, 0, "WARNING (libpng): %s - %s", message, (char *)png_get_error_ptr(png_ptr));
}
static bool OpenPNGFile(const char *filename, uint32 id, bool mask)
{
char png_file[MAX_PATH];
/* Add path separator after 'sprites' if not present */
const char *sep = (filename[0] == PATHSEPCHAR) ? "" : PATHSEP;
snprintf(png_file, sizeof(png_file), "sprites%s%s" PATHSEP "%d%s.png", sep, filename, id, mask ? "m" : "");
if (FioCheckFileExists(png_file, NEWGRF_DIR)) {
FioOpenFile(PNG_SLOT, png_file, NEWGRF_DIR);
return true;
}
/* TODO -- Add TAR support */
return false;
}
static bool LoadPNG(SpriteLoader::Sprite *sprite, const char *filename, uint32 id, volatile bool mask)
{
png_byte header[8];
png_structp png_ptr;
png_infop info_ptr, end_info;
uint bit_depth, colour_type;
uint i, pixelsize;
SpriteLoader::CommonPixel *dst;
if (!OpenPNGFile(filename, id, mask)) return mask; // If mask is true, and file not found, continue true anyway, as it isn't a show-stopper
/* Check the header */
FioReadBlock(header, 8);
if (png_sig_cmp(header, 0, 8) != 0) return false;
/* Create the reader */
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, png_my_error, png_my_warning);
if (png_ptr == NULL) return false;
/* Create initial stuff */
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL) {
png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
return false;
}
end_info = png_create_info_struct(png_ptr);
if (end_info == NULL) {
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
return false;
}
/* Make sure that upon error, we can clean up graceful */
if (setjmp(png_jmpbuf(png_ptr))) {
png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
return false;
}
/* Read the file */
png_set_read_fn(png_ptr, NULL, png_my_read);
png_set_sig_bytes(png_ptr, 8);
png_read_info(png_ptr, info_ptr);
if (!mask) {
/* Read the text chunks */
png_textp text_ptr;
int num_text = 0;
png_get_text(png_ptr, info_ptr, &text_ptr, &num_text);
if (num_text == 0) DEBUG(misc, 0, "Warning: PNG Sprite '%s/%d.png' doesn't have x_offs and y_offs; expect graphical problems", filename, id);
for (int i = 0; i < num_text; i++) {
/* x_offs and y_offs are in the text-chunk of PNG */
if (strcmp("x_offs", text_ptr[i].key) == 0) sprite->x_offs = strtol(text_ptr[i].text, NULL, 0);
if (strcmp("y_offs", text_ptr[i].key) == 0) sprite->y_offs = strtol(text_ptr[i].text, NULL, 0);
}
uint height = png_get_image_height(png_ptr, info_ptr);
uint width = png_get_image_width(png_ptr, info_ptr);
/* Check if sprite dimensions aren't larger than what is allowed in GRF-files. */
if (height > UINT8_MAX || width > UINT16_MAX) {
png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
return false;
}
sprite->height = height;
sprite->width = width;
sprite->AllocateData(sprite->width * sprite->height * ZOOM_LVL_BASE * ZOOM_LVL_BASE);
} else if (sprite->height != png_get_image_height(png_ptr, info_ptr) || sprite->width != png_get_image_width(png_ptr, info_ptr)) {
/* Make sure the mask image isn't larger than the sprite image. */
DEBUG(misc, 0, "Ignoring mask for SpriteID %d as it isn't the same dimension as the masked sprite", id);
png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
return true;
}
bit_depth = png_get_bit_depth(png_ptr, info_ptr);
colour_type = png_get_color_type(png_ptr, info_ptr);
if (mask && (bit_depth != 8 || colour_type != PNG_COLOR_TYPE_PALETTE)) {
DEBUG(misc, 0, "Ignoring mask for SpriteID %d as it isn't a 8 bit palette image", id);
png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
return true;
}
bool win_palette = false;
if (!mask) {
if (bit_depth == 16) png_set_strip_16(png_ptr);
if (colour_type == PNG_COLOR_TYPE_PALETTE) {
png_set_palette_to_rgb(png_ptr);
colour_type = PNG_COLOR_TYPE_RGB;
}
if (colour_type == PNG_COLOR_TYPE_GRAY || colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
png_set_gray_to_rgb(png_ptr);
colour_type = PNG_COLOR_TYPE_RGB;
}
if (colour_type == PNG_COLOR_TYPE_RGB) {
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
/* Create an alpha channel when there is a tRNS chunk */
png_set_tRNS_to_alpha(png_ptr);
} else {
png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
}
}
pixelsize = sizeof(uint32);
} else {
pixelsize = sizeof(uint8);
/* Check whether the DOS greyscale is in place. If not, we assume WIN palette */
png_colorp palette;
int num_palette;
if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette) && num_palette == 256) {
for (uint i = 3; i <= 5; i++) {
/* Allow differences between -4 and +4 */
uint8 intensity = i * 16 - 4;
uint8 diff_r = palette[i].red - intensity;
uint8 diff_g = palette[i].green - intensity;
uint8 diff_b = palette[i].blue - intensity;
if (diff_r > 8 || diff_g > 8 || diff_b > 8) {
win_palette = true;
break;
}
}
}
}
png_bytep row_pointer = AllocaM(png_byte, png_get_image_width(png_ptr, info_ptr) * pixelsize);
for (i = 0; i < png_get_image_height(png_ptr, info_ptr); i++) {
png_read_row(png_ptr, row_pointer, NULL);
dst = sprite->data + i * png_get_image_width(png_ptr, info_ptr);
for (uint x = 0; x < png_get_image_width(png_ptr, info_ptr); x++) {
if (mask) {
if (row_pointer[x * sizeof(uint8)] != 0) {
dst[x].r = 0;
dst[x].g = 0;
dst[x].b = 0;
/* Alpha channel is used from the original image (to allow transparency in remap colours) */
extern const byte _palmap_w2d[];
byte color = row_pointer[x * sizeof(uint8)];
dst[x].m = win_palette ? _palmap_w2d[color] : color;
}
} else {
dst[x].r = row_pointer[x * sizeof(uint32) + 0];
dst[x].g = row_pointer[x * sizeof(uint32) + 1];
dst[x].b = row_pointer[x * sizeof(uint32) + 2];
dst[x].a = row_pointer[x * sizeof(uint32) + 3];
dst[x].m = 0;
}
}
}
png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
return true;
}
bool SpriteLoaderPNG::LoadSprite(SpriteLoader::Sprite *sprite, uint8 file_slot, size_t file_pos, SpriteType sprite_type)
{
const char *filename = FioGetFilename(file_slot);
if (!LoadPNG(sprite, filename, (uint32)file_pos, false)) return false;
if (!LoadPNG(sprite, filename, (uint32)file_pos, true)) return false;
if (ZOOM_LVL_BASE != 1 && sprite_type == ST_NORMAL) {
/* Simple scaling, back-to-front so that no intermediate buffers are needed. */
int width = sprite->width * ZOOM_LVL_BASE;
int height = sprite->height * ZOOM_LVL_BASE;
for (int y = height - 1; y >= 0; y--) {
for (int x = width - 1; x >= 0; x--) {
sprite->data[y * width + x] = sprite->data[y / ZOOM_LVL_BASE * sprite->width + x / ZOOM_LVL_BASE];
}
}
sprite->width *= ZOOM_LVL_BASE;
sprite->height *= ZOOM_LVL_BASE;
sprite->x_offs *= ZOOM_LVL_BASE;
sprite->y_offs *= ZOOM_LVL_BASE;
}
return true;
}
#endif /* WITH_PNG */
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