// d_clear: clears a specified rectangle to the specified color

#include "quakedef.h"


/*
================
D_FillRect
================
*/
void D_FillRect(vrect_t * rect, int color)
{
    int rx, ry, rwidth, rheight;
    unsigned char *dest;
    unsigned *ldest;

    rx = rect->x;
    ry = rect->y;
    rwidth = rect->width;
    rheight = rect->height;

    if (rx < 0) {
	rwidth += rx;
	rx = 0;
    }
    if (ry < 0) {
	rheight += ry;
	ry = 0;
    }
    if (rx + rwidth > vid.width)
	rwidth = vid.width - rx;
    if (ry + rheight > vid.height)
	rheight = vid.height - rx;

    if (rwidth < 1 || rheight < 1)
	return;

    dest = ((byte *) vid.buffer + ry * vid.rowbytes + rx);

    if (((rwidth & 0x03) == 0) && (((long) dest & 0x03) == 0)) {
	// faster aligned dword clear
	ldest = (unsigned *) dest;
	color += color << 16;

	rwidth >>= 2;
	color += color << 8;

	for (ry = 0; ry < rheight; ry++) {
	    for (rx = 0; rx < rwidth; rx++)
		ldest[rx] = color;
	    ldest = (unsigned *) ((byte *) ldest + vid.rowbytes);
	}
    } else {
	// slower byte-by-byte clear for unaligned cases
	for (ry = 0; ry < rheight; ry++) {
	    for (rx = 0; rx < rwidth; rx++)
		dest[rx] = color;
	    dest += vid.rowbytes;
	}
    }
}
