Function AddSortableSpriteToDraw

src/viewport.cpp:663–744

* Draw a (transparent) sprite at given coordinates with a given bounding box. * The bounding box extends from (x + bb_offset_x, y + bb_offset_y, z + bb_offset_z) to (x + w - 1, y + h - 1, z + dz - 1), both corners included. * Bounding boxes with bb_offset_x == w or bb_offset_y == h or bb_offset_z == dz are allowed and produce thin slices. * * @note Bounding boxes are normally specified with bb

 * @param sub Only draw a part of the sprite.
 */
void AddSortableSpriteToDraw(SpriteID image, PaletteID pal, int x, int y, int z, const SpriteBounds &bounds, bool transparent, const SubSprite *sub)
{
	int32_t left, right, top, bottom;

	assert((image & SPRITE_MASK) < MAX_SPRITES);

	/* Move to bounding box. */
	x += bounds.origin.x;
	y += bounds.origin.y;
	z += bounds.origin.z;

	/* make the sprites transparent with the right palette */
	if (transparent) {
		SetBit(image, PALETTE_MODIFIER_TRANSPARENT);
		pal = PALETTE_TO_TRANSPARENT;
	}

	if (_vd.combine_sprites == SPRITE_COMBINE_ACTIVE) {
		AddCombinedSprite(image, pal, x + bounds.offset.x, y + bounds.offset.y, z + bounds.offset.z, sub);
		return;
	}

	_vd.last_child = LAST_CHILD_NONE;

	Point pt = RemapCoords(x + bounds.offset.x, y + bounds.offset.y, z + bounds.offset.z);
	int tmp_left, tmp_top, tmp_x = pt.x, tmp_y = pt.y;

	/* Compute screen extents of sprite */
	if (image == SPR_EMPTY_BOUNDING_BOX) {
		left = tmp_left = RemapCoords(x + bounds.extent.x, y, z).x;
		right           = RemapCoords(x, y + bounds.extent.y, z).x + 1;
		top  = tmp_top  = RemapCoords(x, y, z + bounds.extent.z).y;
		bottom          = RemapCoords(x + bounds.extent.x, y + bounds.extent.y, z).y + 1;
	} else {
		const Sprite *spr = GetSprite(image & SPRITE_MASK, SpriteType::Normal);
		left = tmp_left = (pt.x += spr->x_offs);
		right           = (pt.x +  spr->width );
		top  = tmp_top  = (pt.y += spr->y_offs);
		bottom          = (pt.y +  spr->height);
	}

	if (_draw_bounding_boxes && (image != SPR_EMPTY_BOUNDING_BOX)) {
		/* Compute maximal extents of sprite and its bounding box */
		left   = std::min(left  , RemapCoords(x + bounds.extent.x, y, z).x);
		right  = std::max(right , RemapCoords(x, y + bounds.extent.y, z).x + 1);
		top    = std::min(top   , RemapCoords(x, y, z + bounds.extent.z).y);
		bottom = std::max(bottom, RemapCoords(x + bounds.extent.x, y + bounds.extent.y, z).y + 1);
	}

	/* Do not add the sprite to the viewport, if it is outside */
	if (left   >= _vd.dpi.left + _vd.dpi.width ||
	    right  <= _vd.dpi.left                 ||
	    top    >= _vd.dpi.top + _vd.dpi.height ||
	    bottom <= _vd.dpi.top) {
		return;
	}

	ParentSpriteToDraw &ps = _vd.parent_sprites_to_draw.emplace_back();