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engines/ags/engine/ac/walk_behind.h

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+// Walk-behinds calculation logic.
+
+#ifndef AGS_ENGINE_AC_WALK_BEHIND_H
+#define AGS_ENGINE_AC_WALK_BEHIND_H
+
+#include "ags/shared/util/geometry.h"
+
+namespace AGS3 {
+
+// A method of rendering walkbehinds on screen:
+// DrawAsSeparateSprite - draws whole walkbehind as a sprite;
+//     this method is most simple and is optimal for 3D renderers.
+// DrawOverCharSprite - turns parts of the character and object sprites
+//     transparent when they are covered by walkbehind (walkbehind itself
+//     is not drawn separately in this case);
+//     this method is optimized for software render.
+enum WalkBehindMethodEnum {
+	DrawOverCharSprite,
+	DrawAsSeparateSprite
+};
+
+// An info on vertical column of walk-behind mask, which may contain WB area
+struct WalkBehindColumn {
+	bool Exists = false; // whether any WB area is in this column
+	int Y1 = 0, Y2 = 0; // WB top and bottom Y coords
+};
+
+namespace AGS { namespace Shared { class Bitmap; } }
+using namespace AGS; // FIXME later
+
+// Recalculates walk-behind positions
+void walkbehinds_recalc();
+// Generates walk-behinds as separate sprites
+void walkbehinds_generate_sprites();
+// Edits the given game object's sprite, cutting out pixels covered by walk-behinds;
+// returns whether any pixels were updated
+bool walkbehinds_cropout(Shared::Bitmap *sprit, int sprx, int spry, int basel);
+
+} // namespace AGS3
+
+#endif