Function GUI_DrawLine

src/gui/gui.c:2483–2586

* Draws a line from (x1, y1) to (x2, y2) using given colour. * @param x1 The X-coordinate of the begin of the line. * @param y1 The Y-coordinate of the begin of the line. * @param x2 The X-coordinate of the end of the line. * @param y2 The Y-coordinate of the end of the line. * @param colour The colour to use to draw the line. */

 * @param colour The colour to use to draw the line.
 */
void GUI_DrawLine(int16 x1, int16 y1, int16 x2, int16 y2, uint8 colour)
{
	uint8 *screen = GFX_Screen_GetActive();
	int16 increment = 1;

	if (x1 < g_clipping.left || x1 > g_clipping.right || y1 < g_clipping.top || y1 > g_clipping.bottom || x2 < g_clipping.left || x2 > g_clipping.right || y2 < g_clipping.top || y2 > g_clipping.bottom) {
		while (true) {
			uint16 clip1 = GetNeededClipping(x1, y1);
			uint16 clip2 = GetNeededClipping(x2, y2);

			if (clip1 == 0 && clip2 == 0) break;
			if ((clip1 & clip2) != 0) return;

			switch (clip1) {
				case 1: case 9:  ClipTop(&x1, &y1, x2, y2); break;
				case 2: case 6:  ClipBottom(&x1, &y1, x2, y2); break;
				case 4: case 5:  ClipLeft(&x1, &y1, x2, y2); break;
				case 8: case 10: ClipRight(&x1, &y1, x2, y2); break;
				default:
					switch (clip2) {
						case 1: case 9:  ClipTop(&x2, &y2, x1, y1); break;
						case 2: case 6:  ClipBottom(&x2, &y2, x1, y1); break;
						case 4: case 5:  ClipLeft(&x2, &y2, x1, y1); break;
						case 8: case 10: ClipRight(&x2, &y2, x1, y1); break;
						default: break;
					}
			}
		}
	}

	y2 -= y1;

	if (y2 == 0) {
		if (x1 >= x2) {
			int16 x = x1;
			x1 = x2;
			x2 = x;
		}

		x2 -= x1 - 1;

		screen += y1 * SCREEN_WIDTH + x1;

		memset(screen, colour, x2);
		return;
	}

	if (y2 < 0) {
		int16 x = x1;
		x1 = x2;
		x2 = x;
		y2 = -y2;
		y1 -= y2;
	}

	screen += y1 * SCREEN_WIDTH;

	x2 -= x1;