gdfx.h

Linux/Unix下的绘图函数库（Graphic Drawing Library）

#ifdef __cplusplus
extern "C" {
#endif

#ifndef GDFX_H
#define GDFX_H 1

#include "gd.h"

/* im MUST be square, but can have any size. Returns a new image 
	of width and height radius * 2, in which the X axis of
	the original has been remapped to theta (angle) and the Y axis
	of the original has been remapped to rho (distance from center).
	This is known as a "polar coordinate transform." */

 BGD_DECLARE(gdImagePtr) gdImageSquareToCircle(gdImagePtr im, int radius);

/* Draws the text 'top' and 'bottom' on 'im', curved along the
	edge of a circle of radius 'radius', with its
	center at 'cx' and 'cy'. 'top' is written clockwise
	along the top; 'bottom' is written counterclockwise
	along the bottom. 'textRadius' determines the 'height'
	of each character; if 'textRadius' is 1/2 of 'radius',
	characters extend halfway from the edge to the center.
	'fillPortion' varies from 0 to 1.0, with useful values
	from about 0.4 to 0.9, and determines how much of the
	180 degrees of arc assigned to each section of text
	is actually occupied by text; 0.9 looks better than
	1.0 which is rather crowded. 'font' is a freetype
	font; see gdImageStringFT. 'points' is passed to the
	freetype engine and has an effect on hinting; although
	the size of the text is determined by radius, textRadius,
	and fillPortion, you should pass a point size that
	'hints' appropriately -- if you know the text will be
	large, pass a large point size such as 24.0 to get the 
	best results. 'fgcolor' can be any color, and may have
	an alpha component, do blending, etc. 

	Returns 0 on success, or an error string. */	

BGD_DECLARE(char *) gdImageStringFTCircle(
	gdImagePtr im,
	int cx,
	int cy,
	double radius,
	double textRadius,
	double fillPortion,
	char *font,
	double points,
	char *top,
	char *bottom,
	int fgcolor);

 /* 2.0.16: 
  * Sharpen function added on 2003-11-19
  * by Paul Troughton (paul<dot>troughton<at>ieee<dot>org)
  * Simple 3x3 convolution kernel
  * Makes use of seperability
  * Faster, but less flexible, than full-blown unsharp masking
  * pct is sharpening percentage, and can be greater than 100
  * Silently does nothing to non-truecolor images
  * Silently does nothing for pct<0, as not a useful blurring function
  * Leaves transparency/alpha-channel untouched
  */

 BGD_DECLARE(void) gdImageSharpen (gdImagePtr im, int pct);

#endif /* GDFX_H */


#ifdef __cplusplus
}
#endif