(svn r11174) -Codechange: add possibility to show the bounding boxes of sprites using CTRL-B so one can get a better understanding of the used bounding boxes to fix the glitches that still exist. Patch by frosch.

Note that this is not completely glitch free, bounding boxes sometimes aren't removed properly. This is due to the fact that the bounding boxes sometimes are larger than the sprite, which causes a smaller part than the bounding box to be redrawn. This is NOT a bug, but a known implementation limit as we do not want to slow down normal games so the debug graphics are always 100% correct.

5 files changed, 102 insertions, 14 deletions

diff --git a/src/gfx.cpp b/src/gfx.cpp
index 8a1b9741c..411267525 100644
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -139,6 +139,50 @@ void GfxDrawLine(int x, int y, int x2, int y2, int color)
 	blitter->DrawLine(dpi->dst_ptr, x, y, x2, y2, dpi->width, dpi->height, color);
 }
 
+/**
+ * Draws the projection of a parallelepiped.
+ * This can be used to draw boxes in world coordinates.
+ *
+ * @param x   Screen X-coordinate of top front corner.
+ * @param y   Screen Y-coordinate of top front corner.
+ * @param dx1 Screen X-length of first edge.
+ * @param dy1 Screen Y-length of first edge.
+ * @param dx2 Screen X-length of second edge.
+ * @param dy2 Screen Y-length of second edge.
+ * @param dx3 Screen X-length of third edge.
+ * @param dy3 Screen Y-length of third edge.
+ */
+void DrawBox(int x, int y, int dx1, int dy1, int dx2, int dy2, int dx3, int dy3)
+{
+	/*           ....
+	 *         ..    ....
+	 *       ..          ....
+	 *     ..                ^
+	 *   <--__(dx1,dy1)    /(dx2,dy2)
+	 *   :    --__       /   :
+	 *   :        --__ /     :
+	 *   :            *(x,y) :
+	 *   :            |      :
+	 *   :            |     ..
+	 *    ....        |(dx3,dy3)
+	 *        ....    | ..
+	 *            ....V.
+	 */
+
+	static const byte color = 255;
+
+	GfxDrawLine(x, y, x + dx1, y + dy1, color);
+	GfxDrawLine(x, y, x + dx2, y + dy2, color);
+	GfxDrawLine(x, y, x + dx3, y + dy3, color);
+
+	GfxDrawLine(x + dx1, y + dy1, x + dx1 + dx2, y + dy1 + dy2, color);
+	GfxDrawLine(x + dx1, y + dy1, x + dx1 + dx3, y + dy1 + dy3, color);
+	GfxDrawLine(x + dx2, y + dy2, x + dx2 + dx1, y + dy2 + dy1, color);
+	GfxDrawLine(x + dx2, y + dy2, x + dx2 + dx3, y + dy2 + dy3, color);
+	GfxDrawLine(x + dx3, y + dy3, x + dx3 + dx1, y + dy3 + dy1, color);
+	GfxDrawLine(x + dx3, y + dy3, x + dx3 + dx2, y + dy3 + dy2, color);
+}
+
 
 /** Truncate a given string to a maximum width if neccessary.
  * If the string is truncated, add three dots ('...') to show this.
diff --git a/src/gfx.h b/src/gfx.h
index f54c1fcd9..38d4b3052 100644
--- a/src/gfx.h
+++ b/src/gfx.h
@@ -268,6 +268,7 @@ void DrawStringRightAlignedUnderline(int x, int y, StringID str, uint16 color);
 
 void GfxFillRect(int left, int top, int right, int bottom, int color);
 void GfxDrawLine(int left, int top, int right, int bottom, int color);
+void DrawBox(int x, int y, int dx1, int dy1, int dx2, int dy2, int dx3, int dy3);
 
 BoundingRect GetStringBoundingBox(const char *str);
 uint32 FormatStringLinebreaks(char *str, int maxw);
diff --git a/src/main_gui.cpp b/src/main_gui.cpp
index 447aef59b..95289a1bd 100644
--- a/src/main_gui.cpp
+++ b/src/main_gui.cpp
@@ -59,6 +59,8 @@ static int _scengen_town_size = 1; // depress medium-sized towns per default
 extern void GenerateIndustries();
 extern bool GenerateTowns();
 
+bool _draw_bounding_boxes = false;
+
 
 void CcGiveMoney(bool success, TileIndex tile, uint32 p1, uint32 p2)
 {
@@ -2208,6 +2210,13 @@ static void MainWindowWndProc(Window *w, WindowEvent *e)
 			break;
 		}
 
+		if (e->we.keypress.keycode == ('B' | WKC_CTRL)) {
+			e->we.keypress.cont = false;
+			_draw_bounding_boxes = !_draw_bounding_boxes;
+			MarkWholeScreenDirty();
+			break;
+		}
+
 		if (_game_mode == GM_MENU) break;
 
 		switch (e->we.keypress.keycode) {
diff --git a/src/variables.h b/src/variables.h
index 0b385bb73..9d2b2e4a5 100644
--- a/src/variables.h
+++ b/src/variables.h
@@ -339,6 +339,8 @@ extern const byte _tileh_to_sprite[32];
 
 extern const TileTypeProcs * const _tile_type_procs[16];
 
+extern bool _draw_bounding_boxes;
+
 /* misc */
 VARDEF char _screenshot_name[128];
 VARDEF byte _vehicle_design_names;
diff --git a/src/viewport.cpp b/src/viewport.cpp
index 40abfd242..a33df3db3 100644
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -515,7 +515,7 @@ void AddSortableSpriteToDraw(SpriteID image, SpriteID pal, int x, int y, int w,
 	ViewportDrawer *vd = _cur_vd;
 	ParentSpriteToDraw *ps;
 	Point pt;
-	int32 right, bottom;
+	int32 left, right, top, bottom;
 
 	assert((image & SPRITE_MASK) < MAX_SPRITES);
 
@@ -552,22 +552,32 @@ void AddSortableSpriteToDraw(SpriteID image, SpriteID pal, int x, int y, int w,
 	pt = RemapCoords(x, y, z);
 	ps->x = pt.x;
 	ps->y = pt.y;
+
+	/* Compute screen extents of sprite */
 	if (image == SPR_EMPTY_BOUNDING_BOX) {
-		ps->left = RemapCoords(x + w          , y + bb_offset_y, z + bb_offset_z).x;
-		right    = RemapCoords(x + bb_offset_x, y + h          , z + bb_offset_z).x;
-		ps->top  = RemapCoords(x + bb_offset_x, y + bb_offset_y, z + dz         ).y;
-		bottom   = RemapCoords(x + w          , y + h          , z + bb_offset_z).y;
+		left = ps->left = RemapCoords(x + w          , y + bb_offset_y, z + bb_offset_z).x;
+		right           = RemapCoords(x + bb_offset_x, y + h          , z + bb_offset_z).x + 1;
+		top  = ps->top  = RemapCoords(x + bb_offset_x, y + bb_offset_y, z + dz         ).y;
+		bottom          = RemapCoords(x + w          , y + h          , z + bb_offset_z).y + 1;
 	} else {
 		const Sprite *spr = GetSprite(image & SPRITE_MASK);
-		ps->left = (pt.x += spr->x_offs);
-		right    = (pt.x +  spr->width );
-		ps->top  = (pt.y += spr->y_offs);
-		bottom   = (pt.y +  spr->height);
-	}
-	if (ps->left >= vd->dpi.left + vd->dpi.width ||
-	    right    <= vd->dpi.left ||
-	    ps->top  >= vd->dpi.top + vd->dpi.height ||
-	    bottom   <= vd->dpi.top) {
+		left = ps->left = (pt.x += spr->x_offs);
+		right           = (pt.x +  spr->width );
+		top  = ps->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 it's bounding box */
+		left   = min(left  , RemapCoords(x + w          , y + bb_offset_y, z + bb_offset_z).x);
+		right  = max(right , RemapCoords(x + bb_offset_x, y + h          , z + bb_offset_z).x + 1);
+		top    = min(top   , RemapCoords(x + bb_offset_x, y + bb_offset_y, z + dz         ).y);
+		bottom = max(bottom, RemapCoords(x + w          , y + h          , z + bb_offset_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;
 	}
 
@@ -616,6 +626,7 @@ void AddChildSpriteScreen(SpriteID image, SpriteID pal, int x, int y)
 	}
 	cs = (ChildScreenSpriteToDraw*)vd->spritelist_mem;
 
+	/* If the ParentSprite was clipped by the viewport bounds, do not draw the ChildSprites either */
 	if (vd->last_child == NULL) return;
 
 	vd->spritelist_mem += sizeof(ChildScreenSpriteToDraw);
@@ -1232,6 +1243,26 @@ static void ViewportDrawParentSprites(ParentSpriteToDraw *psd[])
 	}
 }
 
+/**
+ * Draws the bounding boxes of all ParentSprites
+ * @param psd Array of ParentSprites
+ */
+static void ViewportDrawBoundingBoxes(ParentSpriteToDraw *psd[])
+{
+	for (; *psd != NULL; psd++) {
+		const ParentSpriteToDraw* ps = *psd;
+		Point pt1 = RemapCoords(ps->xmax + 1, ps->ymax + 1, ps->zmax + 1); // top front corner
+		Point pt2 = RemapCoords(ps->xmin    , ps->ymax + 1, ps->zmax + 1); // top left corner
+		Point pt3 = RemapCoords(ps->xmax + 1, ps->ymin    , ps->zmax + 1); // top right corner
+		Point pt4 = RemapCoords(ps->xmax + 1, ps->ymax + 1, ps->zmin    ); // bottom front corner
+
+		DrawBox(        pt1.x,         pt1.y,
+		        pt2.x - pt1.x, pt2.y - pt1.y,
+		        pt3.x - pt1.x, pt3.y - pt1.y,
+		        pt4.x - pt1.x, pt4.y - pt1.y);
+	}
+}
+
 static void ViewportDrawStrings(DrawPixelInfo *dpi, const StringSpriteToDraw *ss)
 {
 	DrawPixelInfo dp;
@@ -1355,6 +1386,7 @@ void ViewportDoDraw(const ViewPort *vp, int left, int top, int right, int bottom
 
 	ViewportSortParentSprites(parent_list);
 	ViewportDrawParentSprites(parent_list);
+	if (_draw_bounding_boxes) ViewportDrawBoundingBoxes(parent_list);
 
 	if (vd.first_string != NULL) ViewportDrawStrings(&vd.dpi, vd.first_string);