Create antialising font

Graphics and GPU Programming Programming OpenGL

Started by Hastur June 17, 2005 12:37 PM

3 comments, last by iliak 18 years, 10 months ago

Hastur

122

Author

June 17, 2005 12:37 PM

Hi, I wanna know how can I create an antialiasing font using CreateFont function.. I'm working on OpenGL. thanx

"Really? Have you seen a man eat his own head?" - Spottswoode / Team America World Police

kusma

170

June 17, 2005 02:42 PM

here's the routine i use to create antialiased strings into textures in gl.

char *fonts[] = {	"Times New Roman",	"Arial",};void texture_text(Texture *tex, unsigned font_index, char *string, unsigned size, int xpos, int ypos, unsigned color) {	const unsigned w = tex-&gt;get_w();	const unsigned h = tex-&gt;get_h();	const unsigned width = 1 &lt;&lt; w;	const unsigned height = 1 &lt;&lt; h;	const char *font_name = fonts[font_index];	unsigned *ptr = (unsigned*)tex-&gt;get_data();	HDC hdc = GetDC(0);	HBITMAP bitmap = CreateCompatibleBitmap(hdc, width &lt;&lt; 2, height &lt;&lt; 2);	HDC hdc_mem = CreateCompatibleDC(hdc);	SelectObject(hdc_mem, bitmap);	static LOGFONT lf = {0, 0, 0, 0, FW_NORMAL, 0, 0, 0, 0, 0, 0, ANTIALIASED_QUALITY, 0, 0};	lf.lfHeight = -int(size) * 4;	strcpy(lf.lfFaceName, font_name);	HFONT font = CreateFontIndirect(&lf);	SetBkColor(hdc_mem, 0);	SelectObject(hdc_mem, font);	SetTextColor(hdc_mem, 0xFF0000);	SetTextAlign(hdc_mem, TA_BASELINE | TA_LEFT | TA_NOUPDATECP);	TextOut(hdc_mem, xpos * 4, ypos * 4, string, unsigned(strlen(string)));	unsigned *buffer = new unsigned[width * height * 4 * 4];	static BITMAPINFO bi = {{sizeof(BITMAPINFOHEADER), 0, 0, 1, 32, BI_RGB, 0, 0, 0, 0, 0}, {0 ,0, 0}};	bi.bmiHeader.biWidth = width * 4;	bi.bmiHeader.biHeight = int(height * 4);	GetDIBits(hdc_mem, bitmap, 0, height * 4, buffer, &bi, DIB_RGB_COLORS);	DeleteDC(hdc_mem);	DeleteObject(bitmap);	DeleteObject(font);	unsigned color_alpha = color &gt;&gt; 24;	unsigned int *src = buffer;	for (unsigned y = 0; y &lt; height; y++) {		for (unsigned x = 0; x &lt; width; x++) {			unsigned accum = 0;			unsigned offs = (x &lt;&lt; 2) + (y &lt;&lt; 4) * width;			for (unsigned i=4; i; i--) {				accum += src[offs] + src[offs+1] + src[offs+2] + src[offs+3];				offs += width &lt;&lt; 2;			}			unsigned char alpha = unsigned char(accum &gt;&gt; 4);			alpha = ( alpha * color_alpha ) &gt;&gt; 8;			unsigned int rb1 = *ptr & 0xFF00FF;			unsigned int g1 = *ptr & 0x00FF00;			unsigned int rb2 = color & 0xFF00FF;			unsigned int g2 = color & 0x00FF00;			unsigned dst_alpha = *ptr &gt;&gt; 24;			dst_alpha += alpha;			if (dst_alpha &gt; 255) dst_alpha = 255;			*ptr++ = ((rb1+(((rb2-rb1)*alpha)&gt;&gt;8))&0xFF00FF|(g1+(((g2-g1)*alpha)&gt;&gt;8))&0x00FF00) | (dst_alpha &lt;&lt; 24);		}	}	delete[] buffer;}