(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.

1 files changed, 46 insertions, 14 deletions

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);