netsurf/gtk/bitmap.c
2014-02-16 00:00:21 +00:00

396 lines
9.4 KiB
C

/*
* Copyright 2004 James Bursa <bursa@users.sourceforge.net>
*
* This file is part of NetSurf, http://www.netsurf-browser.org/
*
* NetSurf 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 of the License.
*
* NetSurf 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
/** \file
* Generic bitmap handling (GDK / GTK+ implementation).
*
* This implements the interface given by desktop/bitmap.h using GdkPixbufs.
*/
#include <assert.h>
#include <stdbool.h>
#include <string.h>
#include <cairo.h>
#include <gtk/gtk.h>
#include "content/content.h"
#include "gtk/scaffolding.h"
#include "gtk/bitmap.h"
#include "image/bitmap.h"
#include "utils/log.h"
/**
* Create a bitmap.
*
* \param width width of image in pixels
* \param height width of image in pixels
* \param state a flag word indicating the initial state
* \return an opaque struct bitmap, or NULL on memory exhaustion
*/
void *bitmap_create(int width, int height, unsigned int state)
{
struct bitmap *gbitmap;
gbitmap = calloc(1, sizeof(struct bitmap));
if (gbitmap != NULL) {
if ((state & BITMAP_OPAQUE) != 0) {
gbitmap->surface = cairo_image_surface_create(CAIRO_FORMAT_RGB24, width, height);
} else {
gbitmap->surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, width, height);
}
if (cairo_surface_status(gbitmap->surface) != CAIRO_STATUS_SUCCESS) {
cairo_surface_destroy(gbitmap->surface);
free(gbitmap);
gbitmap = NULL;
}
}
return gbitmap;
}
/**
* Sets whether a bitmap should be plotted opaque
*
* \param vbitmap a bitmap, as returned by bitmap_create()
* \param opaque whether the bitmap should be plotted opaque
*/
void bitmap_set_opaque(void *vbitmap, bool opaque)
{
struct bitmap *gbitmap = (struct bitmap *)vbitmap;
cairo_format_t fmt;
cairo_surface_t *nsurface = NULL;
assert(gbitmap);
fmt = cairo_image_surface_get_format(gbitmap->surface);
if (fmt == CAIRO_FORMAT_RGB24) {
if (opaque == false) {
/* opaque to transparent */
nsurface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32,
cairo_image_surface_get_width(gbitmap->surface),
cairo_image_surface_get_height(gbitmap->surface));
}
} else {
if (opaque == true) {
/* transparent to opaque */
nsurface = cairo_image_surface_create(CAIRO_FORMAT_RGB24,
cairo_image_surface_get_width(gbitmap->surface),
cairo_image_surface_get_height(gbitmap->surface));
}
}
if (nsurface != NULL) {
if (cairo_surface_status(nsurface) != CAIRO_STATUS_SUCCESS) {
cairo_surface_destroy(nsurface);
} else {
memcpy(cairo_image_surface_get_data(nsurface),
cairo_image_surface_get_data(gbitmap->surface),
cairo_image_surface_get_stride(gbitmap->surface) * cairo_image_surface_get_height(gbitmap->surface));
cairo_surface_destroy(gbitmap->surface);
gbitmap->surface = nsurface;
cairo_surface_mark_dirty(gbitmap->surface);
}
}
}
/**
* Tests whether a bitmap has an opaque alpha channel
*
* \param vbitmap a bitmap, as returned by bitmap_create()
* \return whether the bitmap is opaque
*/
bool bitmap_test_opaque(void *vbitmap)
{
struct bitmap *gbitmap = (struct bitmap *)vbitmap;
unsigned char *pixels;
int pcount;
int ploop;
assert(gbitmap);
pixels = cairo_image_surface_get_data(gbitmap->surface);
pcount = cairo_image_surface_get_stride(gbitmap->surface) *
cairo_image_surface_get_height(gbitmap->surface);
for (ploop = 3; ploop < pcount; ploop += 4) {
if (pixels[ploop] != 0xff) {
return false;
}
}
return true;
}
/**
* Gets whether a bitmap should be plotted opaque
*
* \param vbitmap a bitmap, as returned by bitmap_create()
*/
bool bitmap_get_opaque(void *vbitmap)
{
struct bitmap *gbitmap = (struct bitmap *)vbitmap;
cairo_format_t fmt;
assert(gbitmap);
fmt = cairo_image_surface_get_format(gbitmap->surface);
if (fmt == CAIRO_FORMAT_RGB24) {
return true;
}
return false;
}
/**
* Return a pointer to the pixel data in a bitmap.
*
* \param vbitmap a bitmap, as returned by bitmap_create()
* \return pointer to the pixel buffer
*
* The pixel data is packed as BITMAP_FORMAT, possibly with padding at the end
* of rows. The width of a row in bytes is given by bitmap_get_rowstride().
*/
unsigned char *bitmap_get_buffer(void *vbitmap)
{
struct bitmap *gbitmap = (struct bitmap *)vbitmap;
int pixel_loop;
int pixel_count;
uint8_t *pixels;
uint32_t t, r, g, b;
cairo_format_t fmt;
assert(gbitmap);
cairo_surface_flush(gbitmap->surface);
pixels = cairo_image_surface_get_data(gbitmap->surface);
if (!gbitmap->converted)
return pixels;
fmt = cairo_image_surface_get_format(gbitmap->surface);
pixel_count = cairo_image_surface_get_width(gbitmap->surface) *
cairo_image_surface_get_height(gbitmap->surface);
if (fmt == CAIRO_FORMAT_RGB24) {
/* Opaque image: simply swap R & B channels */
for (pixel_loop=0; pixel_loop < pixel_count; pixel_loop++) {
b = pixels[4 * pixel_loop + 0];
r = pixels[4 * pixel_loop + 2];
pixels[4 * pixel_loop + 0] = r;
pixels[4 * pixel_loop + 2] = b;
}
} else {
/* Alpha image: swap R & B channels, and de-multiply alpha */
for (pixel_loop=0; pixel_loop < pixel_count; pixel_loop++) {
b = pixels[4 * pixel_loop + 0];
g = pixels[4 * pixel_loop + 1];
r = pixels[4 * pixel_loop + 2];
t = pixels[4 * pixel_loop + 3];
if (t != 0) {
r = (r << 8) / t;
g = (g << 8) / t;
b = (b << 8) / t;
r = (r > 255) ? 255 : r;
g = (g > 255) ? 255 : g;
b = (b > 255) ? 255 : b;
} else {
r = g = b = 0;
}
pixels[4 * pixel_loop + 0] = r;
pixels[4 * pixel_loop + 1] = g;
pixels[4 * pixel_loop + 2] = b;
pixels[4 * pixel_loop + 3] = t;
}
}
gbitmap->converted = false;
return (unsigned char *) pixels;
}
/**
* Find the width of a pixel row in bytes.
*
* \param vbitmap a bitmap, as returned by bitmap_create()
* \return width of a pixel row in the bitmap
*/
size_t bitmap_get_rowstride(void *vbitmap)
{
struct bitmap *gbitmap = (struct bitmap *)vbitmap;
assert(gbitmap);
return cairo_image_surface_get_stride(gbitmap->surface);
}
/**
* Find the bytes per pixel of a bitmap
*
* \param vbitmap a bitmap, as returned by bitmap_create()
* \return bytes per pixel
*/
size_t bitmap_get_bpp(void *vbitmap)
{
struct bitmap *gbitmap = (struct bitmap *)vbitmap;
assert(gbitmap);
return 4;
}
/**
* Free a bitmap.
*
* \param vbitmap a bitmap, as returned by bitmap_create()
*/
void bitmap_destroy(void *vbitmap)
{
struct bitmap *gbitmap = (struct bitmap *)vbitmap;
assert(gbitmap);
if (gbitmap->surface != NULL) {
cairo_surface_destroy(gbitmap->surface);
}
if (gbitmap->scsurface != NULL) {
cairo_surface_destroy(gbitmap->scsurface);
}
free(gbitmap);
}
/**
* Save a bitmap in the platform's native format.
*
* \param vbitmap a bitmap, as returned by bitmap_create()
* \param path pathname for file
* \param flags modify the behaviour of the save
* \return true on success, false on error and error reported
*/
bool bitmap_save(void *vbitmap, const char *path, unsigned flags)
{
struct bitmap *gbitmap = (struct bitmap *)vbitmap;
assert(gbitmap);
return false;
}
/**
* The bitmap image has changed, so flush any persistant cache.
*
* \param bitmap a bitmap, as returned by bitmap_create()
*/
void bitmap_modified(void *vbitmap) {
struct bitmap *gbitmap = (struct bitmap *)vbitmap;
int pixel_loop;
int pixel_count;
uint8_t *pixels;
uint32_t t, r, g, b;
cairo_format_t fmt;
assert(gbitmap);
fmt = cairo_image_surface_get_format(gbitmap->surface);
pixel_count = cairo_image_surface_get_width(gbitmap->surface) *
cairo_image_surface_get_height(gbitmap->surface);
pixels = cairo_image_surface_get_data(gbitmap->surface);
if (gbitmap->converted) {
cairo_surface_mark_dirty(gbitmap->surface);
return;
}
if (fmt == CAIRO_FORMAT_RGB24) {
/* Opaque image: simply swap R & B channels */
for (pixel_loop=0; pixel_loop < pixel_count; pixel_loop++) {
r = pixels[4 * pixel_loop + 0];
b = pixels[4 * pixel_loop + 2];
pixels[4 * pixel_loop + 0] = b;
pixels[4 * pixel_loop + 2] = r;
}
} else {
/* Alpha image: swap R & B channels, and pre-multiply alpha */
for (pixel_loop=0; pixel_loop < pixel_count; pixel_loop++) {
r = pixels[4 * pixel_loop + 0];
g = pixels[4 * pixel_loop + 1];
b = pixels[4 * pixel_loop + 2];
t = pixels[4 * pixel_loop + 3];
if (t != 0) {
r = ((r * t) >> 8) & 0xff;
g = ((g * t) >> 8) & 0xff;
b = ((b * t) >> 8) & 0xff;
} else {
r = g = b = 0;
}
pixels[4 * pixel_loop + 0] = b;
pixels[4 * pixel_loop + 1] = g;
pixels[4 * pixel_loop + 2] = r;
pixels[4 * pixel_loop + 3] = t;
}
}
cairo_surface_mark_dirty(gbitmap->surface);
gbitmap->converted = true;
}
int bitmap_get_width(void *vbitmap){
struct bitmap *gbitmap = (struct bitmap *)vbitmap;
assert(gbitmap);
return cairo_image_surface_get_width(gbitmap->surface);
}
int bitmap_get_height(void *vbitmap){
struct bitmap *gbitmap = (struct bitmap *)vbitmap;
assert(gbitmap);
return cairo_image_surface_get_height(gbitmap->surface);
}