Function PocoClipPush

modules/commodetto/commodettoPocoBlit.c:3721–3778

#endif

int PocoClipPush(Poco poco, PocoCoordinate x, PocoCoordinate y, PocoDimension w, PocoDimension h)
{
	PocoCoordinate xMax, yMax;
	PocoRectangle clip = (PocoRectangle)(poco->displayListEnd - sizeof(PocoRectangleRecord)); 
	if ((char *)clip < (char *)poco->next) {
		poco->flags |= kPocoFlagErrorStackProblem;
		pocoInstrumentationMax(PocoDisplayListUsed, (char *)poco->next - (char *)poco->displayList);
		return 0;
	}

	rotateCoordinatesAndDimensions(poco->width, poco->height, x, y, w, h);

	poco->stackDepth++;
	poco->displayListEnd = (char *)clip;

	// save current clip
	clip->x = poco->x;
	clip->y = poco->y;
	clip->w = poco->w;
	clip->h = poco->h;

	// intersect new clip with current clip
	xMax = x + w;
	yMax = y + h;

	if (x < poco->x)
		x = poco->x;

	if (xMax > poco->xMax)
		xMax = poco->xMax;

	if (y < poco->y)
		y = poco->y;

	if (yMax > poco->yMax)
		yMax = poco->yMax;

	if ((x >= xMax) || (y >= yMax)) {
		// clipped out
		poco->x = 0;
		poco->y = 0;
		poco->w = 0;
		poco->h = 0;
		poco->xMax = 0;
		poco->yMax = 0;
		return 0;
	}

	// apply new clip
	poco->x = x;
	poco->y = y;
	poco->w = xMax - x;
	poco->h = yMax - y;
	poco->xMax = xMax;
	poco->yMax = yMax;

	return 1;
}