#include "client.h"
#include <errno.h>
#include <gtk/gtk.h>
#include <png.h>

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Macros
#define	BPP 4

#define	MAX_IMAGE_HEIGHT 1024

#define	MAX_IMAGE_WIDTH 1024

#define	PNGX_DATA 3

#define	PNGX_NOFILE 1

#define	PNGX_OUTOFMEM 2

#define	RATIO 100

Functions
guint8 *	png_to_data (guint8 data, int len, guint32 width, guint32 *height)

guint8 *	rescale_rgba_data (guint8 data, int width, int *height, int scale)

cairo_surface_t *	rgba_to_cairo_surface (guint8 *data, int width, int height)

GdkPixbuf *	rgba_to_gdkpixbuf (guint8 *data, int width, int height)

static void	user_read_data (png_structp png_ptr, png_bytep data, png_size_t length)

Variables
static guint8 *	data_cp

static int	data_len

static int	data_start

Detailed Description

Functions for manipulating graphics in the GTK-V2 client.

Definition in file png.c.

Macro Definition Documentation

◆ BPP

#define BPP 4

Definition at line 205 of file png.c.

◆ MAX_IMAGE_HEIGHT

#define MAX_IMAGE_HEIGHT 1024

Definition at line 204 of file png.c.

◆ MAX_IMAGE_WIDTH

#define MAX_IMAGE_WIDTH 1024

Definition at line 203 of file png.c.

◆ PNGX_DATA

#define PNGX_DATA 3

Definition at line 32 of file png.c.

◆ PNGX_NOFILE

#define PNGX_NOFILE 1

Definition at line 30 of file png.c.

◆ PNGX_OUTOFMEM

#define PNGX_OUTOFMEM 2

Definition at line 31 of file png.c.

◆ RATIO

#define RATIO 100

Definition at line 201 of file png.c.

Function Documentation

◆ png_to_data()

guint8* png_to_data	(	guint8 *	data,
		int	len,
		guint32 *	width,
		guint32 *	height
	)

Definition at line 49 of file png.c.

References data_cp, data_len, data_start, height, LOG(), LOG_CRITICAL, LOG_ERROR, user_read_data(), and width.

Referenced by display_newpng(), and finish_face_cmd().

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◆ rescale_rgba_data()

guint8* rescale_rgba_data	(	guint8 *	data,
		int *	width,
		int *	height,
		int	scale
	)

Takes png data and scales it accordingly. This function is based on pnmscale, but has been modified to support alpha channel - instead of blending the alpha channel, it takes the most opaque value - blending it is not likely to give sane results IMO - for any image that has transparent information, if we blended the alpha, the result would be the edges of that region being partially transparent. This function has also been re-written to use more static data - in the case of the client, it will be called thousands of times, so it doesn't make sense to free the data and then re-allocate it.

For pixels that are fully transparent, the end result after scaling is they will be tranparent black. This is a needed effect for blending to work properly.

This function returns a new pointer to the scaled image data. This is g_malloc'd data, so should be freed at some point to prevent leaks. This function does not modify the data passed to it - the caller is responsible for freeing it if it is no longer needed.

function arguments:

Parameters

*data	PNG data - this is any 4 byte per pixel data, in RGBA format.
*width	Source width modified to contain the new image size.
*height	Source height modified to contain the new image size.
scale	Percentage size that new image should be. 100 is a same size image - values larger than 100 will result in zoom, values less than 100 will result in a shrinkage.

Definition at line 235 of file png.c.

References BPP, height, LOG(), LOG_CRITICAL, MAX_IMAGE_HEIGHT, MAX_IMAGE_WIDTH, RATIO, and width.

Referenced by create_and_rescale_image_from_data(), and map_init().

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