293 lines
9.2 KiB
C
293 lines
9.2 KiB
C
#pragma once
|
|
|
|
#include <cairo.h>
|
|
#include "closure.h"
|
|
#include <cmath> // round
|
|
#include <cstdlib>
|
|
#include <cstring>
|
|
#include <png.h>
|
|
#include <pngconf.h>
|
|
|
|
#if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
|
|
#define likely(expr) (__builtin_expect (!!(expr), 1))
|
|
#define unlikely(expr) (__builtin_expect (!!(expr), 0))
|
|
#else
|
|
#define likely(expr) (expr)
|
|
#define unlikely(expr) (expr)
|
|
#endif
|
|
|
|
static void canvas_png_flush(png_structp png_ptr) {
|
|
/* Do nothing; fflush() is said to be just a waste of energy. */
|
|
(void) png_ptr; /* Stifle compiler warning */
|
|
}
|
|
|
|
/* Converts native endian xRGB => RGBx bytes */
|
|
static void canvas_convert_data_to_bytes(png_structp png, png_row_infop row_info, png_bytep data) {
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < row_info->rowbytes; i += 4) {
|
|
uint8_t *b = &data[i];
|
|
uint32_t pixel;
|
|
|
|
memcpy(&pixel, b, sizeof (uint32_t));
|
|
|
|
b[0] = (pixel & 0xff0000) >> 16;
|
|
b[1] = (pixel & 0x00ff00) >> 8;
|
|
b[2] = (pixel & 0x0000ff) >> 0;
|
|
b[3] = 0;
|
|
}
|
|
}
|
|
|
|
/* Unpremultiplies data and converts native endian ARGB => RGBA bytes */
|
|
static void canvas_unpremultiply_data(png_structp png, png_row_infop row_info, png_bytep data) {
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < row_info->rowbytes; i += 4) {
|
|
uint8_t *b = &data[i];
|
|
uint32_t pixel;
|
|
uint8_t alpha;
|
|
|
|
memcpy(&pixel, b, sizeof (uint32_t));
|
|
alpha = (pixel & 0xff000000) >> 24;
|
|
if (alpha == 0) {
|
|
b[0] = b[1] = b[2] = b[3] = 0;
|
|
} else {
|
|
b[0] = (((pixel & 0xff0000) >> 16) * 255 + alpha / 2) / alpha;
|
|
b[1] = (((pixel & 0x00ff00) >> 8) * 255 + alpha / 2) / alpha;
|
|
b[2] = (((pixel & 0x0000ff) >> 0) * 255 + alpha / 2) / alpha;
|
|
b[3] = alpha;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Converts RGB16_565 format data to RGBA32 */
|
|
static void canvas_convert_565_to_888(png_structp png, png_row_infop row_info, png_bytep data) {
|
|
// Loop in reverse to unpack in-place.
|
|
for (ptrdiff_t col = row_info->width - 1; col >= 0; col--) {
|
|
uint8_t* src = &data[col * sizeof(uint16_t)];
|
|
uint8_t* dst = &data[col * 3];
|
|
uint16_t pixel;
|
|
|
|
memcpy(&pixel, src, sizeof(uint16_t));
|
|
|
|
// Convert and rescale to the full 0-255 range
|
|
// See http://stackoverflow.com/a/29326693
|
|
const uint8_t red5 = (pixel & 0xF800) >> 11;
|
|
const uint8_t green6 = (pixel & 0x7E0) >> 5;
|
|
const uint8_t blue5 = (pixel & 0x001F);
|
|
|
|
dst[0] = ((red5 * 255 + 15) / 31);
|
|
dst[1] = ((green6 * 255 + 31) / 63);
|
|
dst[2] = ((blue5 * 255 + 15) / 31);
|
|
}
|
|
}
|
|
|
|
struct canvas_png_write_closure_t {
|
|
cairo_write_func_t write_func;
|
|
PngClosure* closure;
|
|
};
|
|
|
|
#ifdef PNG_SETJMP_SUPPORTED
|
|
bool setjmp_wrapper(png_structp png) {
|
|
return setjmp(png_jmpbuf(png));
|
|
}
|
|
#endif
|
|
|
|
static cairo_status_t canvas_write_png(cairo_surface_t *surface, png_rw_ptr write_func, canvas_png_write_closure_t *closure) {
|
|
unsigned int i;
|
|
cairo_status_t status = CAIRO_STATUS_SUCCESS;
|
|
uint8_t *data;
|
|
png_structp png;
|
|
png_infop info;
|
|
png_bytep *volatile rows = NULL;
|
|
png_color_16 white;
|
|
int png_color_type;
|
|
int bpc;
|
|
unsigned int width = cairo_image_surface_get_width(surface);
|
|
unsigned int height = cairo_image_surface_get_height(surface);
|
|
|
|
data = cairo_image_surface_get_data(surface);
|
|
if (data == NULL) {
|
|
status = CAIRO_STATUS_SURFACE_TYPE_MISMATCH;
|
|
return status;
|
|
}
|
|
cairo_surface_flush(surface);
|
|
|
|
if (width == 0 || height == 0) {
|
|
status = CAIRO_STATUS_WRITE_ERROR;
|
|
return status;
|
|
}
|
|
|
|
rows = (png_bytep *) malloc(height * sizeof (png_byte*));
|
|
if (unlikely(rows == NULL)) {
|
|
status = CAIRO_STATUS_NO_MEMORY;
|
|
return status;
|
|
}
|
|
|
|
int stride = cairo_image_surface_get_stride(surface);
|
|
for (i = 0; i < height; i++) {
|
|
rows[i] = (png_byte *) data + i * stride;
|
|
}
|
|
|
|
#ifdef PNG_USER_MEM_SUPPORTED
|
|
png = png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL, NULL, NULL, NULL);
|
|
#else
|
|
png = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
|
|
#endif
|
|
|
|
if (unlikely(png == NULL)) {
|
|
status = CAIRO_STATUS_NO_MEMORY;
|
|
free(rows);
|
|
return status;
|
|
}
|
|
|
|
info = png_create_info_struct (png);
|
|
if (unlikely(info == NULL)) {
|
|
status = CAIRO_STATUS_NO_MEMORY;
|
|
png_destroy_write_struct(&png, &info);
|
|
free(rows);
|
|
return status;
|
|
|
|
}
|
|
|
|
#ifdef PNG_SETJMP_SUPPORTED
|
|
if (setjmp_wrapper(png)) {
|
|
png_destroy_write_struct(&png, &info);
|
|
free(rows);
|
|
return status;
|
|
}
|
|
#endif
|
|
|
|
png_set_write_fn(png, closure, write_func, canvas_png_flush);
|
|
png_set_compression_level(png, closure->closure->compressionLevel);
|
|
png_set_filter(png, 0, closure->closure->filters);
|
|
if (closure->closure->resolution != 0) {
|
|
uint32_t res = static_cast<uint32_t>(round(static_cast<double>(closure->closure->resolution) * 39.3701));
|
|
png_set_pHYs(png, info, res, res, PNG_RESOLUTION_METER);
|
|
}
|
|
|
|
cairo_format_t format = cairo_image_surface_get_format(surface);
|
|
|
|
switch (format) {
|
|
case CAIRO_FORMAT_ARGB32:
|
|
bpc = 8;
|
|
png_color_type = PNG_COLOR_TYPE_RGB_ALPHA;
|
|
break;
|
|
#ifdef CAIRO_FORMAT_RGB30
|
|
case CAIRO_FORMAT_RGB30:
|
|
bpc = 10;
|
|
png_color_type = PNG_COLOR_TYPE_RGB;
|
|
break;
|
|
#endif
|
|
case CAIRO_FORMAT_RGB24:
|
|
bpc = 8;
|
|
png_color_type = PNG_COLOR_TYPE_RGB;
|
|
break;
|
|
case CAIRO_FORMAT_A8:
|
|
bpc = 8;
|
|
png_color_type = PNG_COLOR_TYPE_GRAY;
|
|
break;
|
|
case CAIRO_FORMAT_A1:
|
|
bpc = 1;
|
|
png_color_type = PNG_COLOR_TYPE_GRAY;
|
|
#ifndef WORDS_BIGENDIAN
|
|
png_set_packswap(png);
|
|
#endif
|
|
break;
|
|
case CAIRO_FORMAT_RGB16_565:
|
|
bpc = 8; // 565 gets upconverted to 888
|
|
png_color_type = PNG_COLOR_TYPE_RGB;
|
|
break;
|
|
case CAIRO_FORMAT_INVALID:
|
|
default:
|
|
status = CAIRO_STATUS_INVALID_FORMAT;
|
|
png_destroy_write_struct(&png, &info);
|
|
free(rows);
|
|
return status;
|
|
}
|
|
|
|
if ((format == CAIRO_FORMAT_A8 || format == CAIRO_FORMAT_A1) &&
|
|
closure->closure->palette != NULL) {
|
|
png_color_type = PNG_COLOR_TYPE_PALETTE;
|
|
}
|
|
|
|
png_set_IHDR(png, info, width, height, bpc, png_color_type, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
|
|
|
|
if (png_color_type == PNG_COLOR_TYPE_PALETTE) {
|
|
size_t nColors = closure->closure->nPaletteColors;
|
|
uint8_t* colors = closure->closure->palette;
|
|
uint8_t backgroundIndex = closure->closure->backgroundIndex;
|
|
png_colorp pngPalette = (png_colorp)png_malloc(png, nColors * sizeof(png_colorp));
|
|
png_bytep transparency = (png_bytep)png_malloc(png, nColors * sizeof(png_bytep));
|
|
for (i = 0; i < nColors; i++) {
|
|
pngPalette[i].red = colors[4 * i];
|
|
pngPalette[i].green = colors[4 * i + 1];
|
|
pngPalette[i].blue = colors[4 * i + 2];
|
|
transparency[i] = colors[4 * i + 3];
|
|
}
|
|
png_set_PLTE(png, info, pngPalette, nColors);
|
|
png_set_tRNS(png, info, transparency, nColors, NULL);
|
|
png_set_packing(png); // pack pixels
|
|
// have libpng free palette and trans:
|
|
png_data_freer(png, info, PNG_DESTROY_WILL_FREE_DATA, PNG_FREE_PLTE | PNG_FREE_TRNS);
|
|
png_color_16 bkg;
|
|
bkg.index = backgroundIndex;
|
|
png_set_bKGD(png, info, &bkg);
|
|
}
|
|
|
|
if (png_color_type != PNG_COLOR_TYPE_PALETTE) {
|
|
white.gray = (1 << bpc) - 1;
|
|
white.red = white.blue = white.green = white.gray;
|
|
png_set_bKGD(png, info, &white);
|
|
}
|
|
|
|
/* We have to call png_write_info() before setting up the write
|
|
* transformation, since it stores data internally in 'png'
|
|
* that is needed for the write transformation functions to work.
|
|
*/
|
|
png_write_info(png, info);
|
|
if (png_color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
|
|
png_set_write_user_transform_fn(png, canvas_unpremultiply_data);
|
|
} else if (format == CAIRO_FORMAT_RGB16_565) {
|
|
png_set_write_user_transform_fn(png, canvas_convert_565_to_888);
|
|
} else if (png_color_type == PNG_COLOR_TYPE_RGB) {
|
|
png_set_write_user_transform_fn(png, canvas_convert_data_to_bytes);
|
|
png_set_filler(png, 0, PNG_FILLER_AFTER);
|
|
}
|
|
|
|
png_write_image(png, rows);
|
|
png_write_end(png, info);
|
|
|
|
png_destroy_write_struct(&png, &info);
|
|
free(rows);
|
|
return status;
|
|
}
|
|
|
|
static void canvas_stream_write_func(png_structp png, png_bytep data, png_size_t size) {
|
|
cairo_status_t status;
|
|
struct canvas_png_write_closure_t *png_closure;
|
|
|
|
png_closure = (struct canvas_png_write_closure_t *) png_get_io_ptr(png);
|
|
status = png_closure->write_func(png_closure->closure, data, size);
|
|
if (unlikely(status)) {
|
|
cairo_status_t *error = (cairo_status_t *) png_get_error_ptr(png);
|
|
if (*error == CAIRO_STATUS_SUCCESS) {
|
|
*error = status;
|
|
}
|
|
png_error(png, NULL);
|
|
}
|
|
}
|
|
|
|
static cairo_status_t canvas_write_to_png_stream(cairo_surface_t *surface, cairo_write_func_t write_func, PngClosure* closure) {
|
|
struct canvas_png_write_closure_t png_closure;
|
|
|
|
if (cairo_surface_status(surface)) {
|
|
return cairo_surface_status(surface);
|
|
}
|
|
|
|
png_closure.write_func = write_func;
|
|
png_closure.closure = closure;
|
|
|
|
return canvas_write_png(surface, canvas_stream_write_func, &png_closure);
|
|
}
|