#include <stdio.h>
#include <math.h>

#include <ft2build.h> 
#include FT_FREETYPE_H 
#include FT_GLYPH_H 
#include FT_OUTLINE_H 
#include FT_SYNTHESIS_H 
#include FT_STROKER_H

static FT_Library freetype_library = NULL;
 
#define WIDTH 320
#define HEIGHT 240

#define setvector(pv, px, py) (pv).x = ((int) (px)) << 6; (pv).y = ((int) (py)) << 6;
#define Float2Fixed(fl) ((FT_Fixed)((fl)*65536.0f))

#ifndef M_PI
#define M_PI      3.14159265358979323846
#endif 

int main(int argc, char *argv[])
{
	FT_Stroker stroker;
	FT_UInt points, contours;
	FT_Outline outline;
	FT_BBox bbox;
	FT_Bitmap bm;	
	FT_Vector v;
	int k, x, y, xmin, ymin, xmax, ymax, pixelwidth, pixelheight;
	unsigned char *buf, *ptr;
			
	FT_Init_FreeType(&freetype_library);
	
	for(k = 0; k < 360; k++) {
		
		FT_Stroker_New(freetype_library, &stroker);

		setvector(v, 0, 0);
		FT_Stroker_BeginSubPath(stroker, &v, 0);
		FT_Stroker_LineTo(stroker, &v);
		
		setvector(v, 0, 0);
		FT_Stroker_LineTo(stroker, &v);

		setvector(v, 0, HEIGHT);
		FT_Stroker_LineTo(stroker, &v);

		setvector(v, WIDTH, HEIGHT);
		FT_Stroker_LineTo(stroker, &v);			

		setvector(v, WIDTH, 0);
		FT_Stroker_LineTo(stroker, &v);			

		setvector(v, 0, 0);
		FT_Stroker_LineTo(stroker, &v);
					
		FT_Stroker_EndSubPath(stroker);
	
		FT_Stroker_GetBorderCounts(stroker, FT_STROKER_BORDER_LEFT, &points, &contours);
		
		memset(&outline, 0, sizeof(FT_Outline));
		FT_Outline_New(freetype_library, 1024, 512, &outline);

		outline.n_points = 0;
		outline.n_contours = 0;
		FT_Stroker_Export(stroker, &outline);	
				
		FT_Stroker_Done(stroker);
		
		if(1) {
		
			double angle = (double) (360 - k) * (M_PI / (double) 180);		
			FT_Matrix m;
				
			m.xx = Float2Fixed(cos(angle));
			m.xy = Float2Fixed(-sin(angle));
			m.yx = Float2Fixed(sin(angle));
			m.yy = Float2Fixed(cos(angle));
			
			FT_Outline_Transform(&outline, &m);	
		}
	
		FT_Outline_Get_BBox(&outline, &bbox);

		xmin = bbox.xMin >> 6;
		ymin = bbox.yMin >> 6;
		xmax = bbox.xMax >> 6;
		ymax = bbox.yMax >> 6;
		
		if(bbox.xMax & 0x3f) xmax++;
		if(bbox.yMax & 0x3f) ymax++;

		pixelwidth = xmax - xmin;
		pixelheight = ymax - ymin;
	
		buf = calloc(pixelwidth * pixelheight, 1);
					
		FT_Outline_Translate(&outline, -bbox.xMin, -bbox.yMin);
		
		memset(&bm, 0, sizeof(FT_Bitmap));
		bm.rows = pixelheight;
		bm.width = pixelwidth;
		bm.pitch = pixelwidth;
		bm.buffer = buf;
		bm.num_grays = 256;
		bm.pixel_mode = FT_PIXEL_MODE_GRAY;

		FT_Outline_Get_Bitmap(freetype_library, &outline, &bm);
	
		printf("*** NOW CHECKING ROTATION ANGLE: %d\n", k);
		
		ptr = buf;
		
		for(y = 0; y < bm.rows; y++) {
			
			int ok = 0;
			
			for(x = 0; x < bm.width; x++) {
				if(ptr[x]) {
					ok = 1;
					break;
				}
			}		
			
			if(!ok) printf("--> EMPTY ROW: %d\n", y);
				
			ptr += bm.pitch;
		}
		
		ptr = buf;
		
		for(x = 0; x < bm.width; x++) {
			
			int ok = 0;
			
			ptr = buf + x;
			
			for(y = 0; y < bm.rows; y++) {
				if(*ptr) {
					ok = 1;
					break;
				}
				ptr += bm.pitch;
			}
				
			if(!ok) printf("--> EMPTY COLUMN: %d\n", x);
		}				
		
		free(buf);
	
		FT_Outline_Done(freetype_library, &outline);	
	}
	
	FT_Done_FreeType(freetype_library);
			
	return 0;
}