palib/source/arm9/PA_Draw8bitEx.c

#include <PA9.h>

void PA_Draw8bitLine(u8 screen, u16 x1, u16 y1, u16 x2, u16 y2, u8 color) {
	int i, dx, dy, sdx, sdy, dxabs, dyabs, x, y, px, py;
	dx = x2 - x1;  /* the horizontal distance of the line */
	dy = y2 - y1;  /* the vertical distance of the line */
	dxabs = dx;
	sdx = 1;

	if (dx < 0) {
		dxabs = -dx;
		sdx = -1;
	}

	dyabs = dy;
	sdy = 1;

	if (dy < 0) {
		dyabs = -dy;
		sdy = -1;
	}

	x = dyabs >> 1;
	y = dxabs >> 1;
	px = x1;
	py = y1;
	PA_Put8bitPixel(screen, px, py, color);

	if (dxabs >= dyabs) {
		for (i = 0; i < dxabs; i++)  {
			y += dyabs;

			if (y >= dxabs)  {
				y -= dxabs;
				py += sdy;
			}

			px += sdx;
			PA_Put8bitPixel(screen, px, py, color);
		}
	} else {
		for (i = 0; i < dyabs; i++) {
			x += dxabs;

			if (x >= dyabs)  {
				x -= dyabs;
				px += sdx;
			}

			py += sdy;
			PA_Put8bitPixel(screen, px, py, color);
		}
	}
}

void PA_8bitDraw(u8 screen, u8 color) {
// Si nouvelle pression, on fait juste un point. Sinon, on trace un trait entre les 2 points...
	if (Stylus.Newpress) {
		s16 low = (PA_drawsize[screen] >> 1) - PA_drawsize[screen] + 1;
		s16 high = (PA_drawsize[screen] >> 1) + 1;
		s16 i = 0, j = 0;

		for (i = low; i < high; i++)
			for (j = low; j < high; j++)
				if ((Stylus.X + i >= 0) && (Stylus.Y + j >= 0) && (Stylus.X + i < 256) && (Stylus.Y + j < 192))
					PA_Put8bitPixel(screen, Stylus.X + i, Stylus.Y + j, color);
	} else if (Stylus.Held) {
		if (PA_olddowntime[screen] != (Stylus.Downtime - 1)) {
			PA_oldx[screen] = Stylus.X; PA_oldy[screen] = Stylus.Y;
		}

		PA_Draw8bitLineEx(screen, Stylus.X, Stylus.Y, PA_oldx[screen], PA_oldy[screen], color, PA_drawsize[screen]);
	}

	PA_oldx[screen] = Stylus.X; PA_oldy[screen] = Stylus.Y; PA_olddowntime[screen] = Stylus.Downtime;
}

void PA_Draw8bitLineEx(u8 screen, s16 basex, s16 basey, s16 endx, s16 endy, u8 color, s8 size) {
	s8 low = (size >> 1) - size + 1;
	s8 high = (size >> 1) + 1;
	s16 i, j;
	s16 x1, x2, y1, y2;

	for (i = low; i < high; i++) {
		for (j = low; j < high; j++) {
			if ((basex + i >= 0) && (basey + j >= 0) && (basex + i < 256) && (basey + j < 192)) {
				PA_Put8bitPixel(screen, basex + i, basey + j, color);
			}
		}
	}

	for (i = low; i < high; i++) {
		j = low;
		x1 = basex + i; x2 = endx + i; y1 = basey + j; y2 = endy + j;

		while (x1 < 0) x1++;	
		while (x1 > 255) x1--;

		while (x2 < 0) x2++;	
		while (x2 > 255) x2--;

		while (y1 < 0) y1++;	
		while (y1 > 191) y1--;

		while (y2 < 0) y2++;	
		while (y2 > 191) y2--;

		PA_Draw8bitLine(screen, x1, y1, x2, y2, color);
		j = high - 1;
		x1 = basex + i; x2 = endx + i; y1 = basey + j; y2 = endy + j;

		while (x1 < 0) x1++;	
		while (x1 > 255) x1--;

		while (x2 < 0) x2++;	
		while (x2 > 255) x2--;

		while (y1 < 0) y1++;	
		while (y1 > 191) y1--;

		while (y2 < 0) y2++;	
		while (y2 > 191) y2--;

		PA_Draw8bitLine(screen, x1, y1, x2, y2, color);
	}

	for (j = low; j < high; j++) {
		i = low;
		x1 = basex + i; x2 = endx + i; y1 = basey + j; y2 = endy + j;

		while (x1 < 0) x1++;	
		while (x1 > 255) x1--;

		while (x2 < 0) x2++;	
		while (x2 > 255) x2--;

		while (y1 < 0) y1++;	
		while (y1 > 191) y1--;

		while (y2 < 0) y2++;	
		while (y2 > 191) y2--;

		PA_Draw8bitLine(screen, x1, y1, x2, y2, color);
		i = high - 1;
		x1 = basex + i; x2 = endx + i; y1 = basey + j; y2 = endy + j;

		while (x1 < 0) x1++;	
		while (x1 > 255) x1--;

		while (x2 < 0) x2++;	
		while (x2 > 255) x2--;

		while (y1 < 0) y1++;	
		while (y1 > 191) y1--;

		while (y2 < 0) y2++;	
		while (y2 > 191) y2--;

		PA_Draw8bitLine(screen, x1, y1, x2, y2, color);
	}
}