Cleanup: Give `SetDirtyBlocks` a more descriptive name.

src/gfx.cpp

@@ -1416,6 +1416,16 @@ void DrawMouseCursor()
 	_cursor.dirty = false;
 }
 
+/**
+ * Repaints a specific rectangle of the screen.
+ *
+ * @param left,top,right,bottom The area of the screen that needs repainting
+ * @pre The rectangle should have been previously marked dirty with \c AddDirtyBlock.
+ * @see AddDirtyBlock
+ * @see DrawDirtyBlocks
+ * @ingroup dirty
+ *
+ */
 void RedrawScreenRect(int left, int top, int right, int bottom)
 {
 	assert(right <= _screen.width && bottom <= _screen.height);
@@ -1438,7 +1448,9 @@ void RedrawScreenRect(int left, int top, int right, int bottom)
 /**
  * Repaints the rectangle blocks which are marked as 'dirty'.
  *
- * @see SetDirtyBlocks
+ * @see AddDirtyBlock
+ *
+ * @ingroup dirty
  */
 void DrawDirtyBlocks()
 {
@@ -1541,21 +1553,18 @@ void DrawDirtyBlocks()
 }
 
 /**
- * This function extends the internal _invalid_rect rectangle as it
- * now contains the rectangle defined by the given parameters. Note
- * the point (0,0) is top left.
+ * Extend the internal _invalid_rect rectangle to contain the rectangle
+ * defined by the given parameters. Note the point (0,0) is top left.
  *
  * @param left The left edge of the rectangle
  * @param top The top edge of the rectangle
  * @param right The right edge of the rectangle
  * @param bottom The bottom edge of the rectangle
  * @see DrawDirtyBlocks
+ * @ingroup dirty
  *
- * @todo The name of the function should be called like @c AddDirtyBlock as
- *       it neither set a dirty rect nor add several dirty rects although
- *       the function name is in plural. (Progman)
  */
-void SetDirtyBlocks(int left, int top, int right, int bottom)
+void AddDirtyBlock(int left, int top, int right, int bottom)
 {
 	byte *b;
 	int width;
@@ -1600,7 +1609,7 @@ void SetDirtyBlocks(int left, int top, int right, int bottom)
  */
 void MarkWholeScreenDirty()
 {
-	SetDirtyBlocks(0, 0, _screen.width, _screen.height);
+	AddDirtyBlock(0, 0, _screen.width, _screen.height);
 }
 
 /**

src/gfx_func.h

@@ -131,7 +131,7 @@ Point GetCharPosInString(const char *str, const char *ch, FontSize start_fontsiz
 const char *GetCharAtPosition(const char *str, int x, FontSize start_fontsize = FS_NORMAL);
 
 void DrawDirtyBlocks();
-void SetDirtyBlocks(int left, int top, int right, int bottom);
+void AddDirtyBlock(int left, int top, int right, int bottom);
 void MarkWholeScreenDirty();
 
 void GfxInitPalettes();

src/news_gui.cpp

@@ -571,7 +571,7 @@ private:
 		if (this->viewport != nullptr) this->viewport->top += newtop - this->top;
 		this->top = newtop;
 
-		SetDirtyBlocks(this->left, mintop, this->left + this->width, maxtop + this->height);
+		AddDirtyBlock(this->left, mintop, this->left + this->width, maxtop + this->height);
 	}
 
 	StringID GetCompanyMessageString() const

src/viewport.cpp

@@ -1886,7 +1886,7 @@ static void MarkViewportDirty(const ViewPort *vp, int left, int top, int right,
 
 	if (top >= vp->virtual_height) return;
 
-	SetDirtyBlocks(
+	AddDirtyBlock(
 		UnScaleByZoomLower(left, vp->zoom) + vp->left,
 		UnScaleByZoomLower(top, vp->zoom) + vp->top,
 		UnScaleByZoom(right, vp->zoom) + vp->left + 1,

src/widget.cpp

@@ -774,7 +774,7 @@ void NWidgetBase::SetDirty(const Window *w) const
 {
 	int abs_left = w->left + this->pos_x;
 	int abs_top = w->top + this->pos_y;
-	SetDirtyBlocks(abs_left, abs_top, abs_left + this->current_x, abs_top + this->current_y);
+	AddDirtyBlock(abs_left, abs_top, abs_left + this->current_x, abs_top + this->current_y);
 }
 
 /**

src/window.cpp

@@ -983,7 +983,7 @@ void DrawOverlappedWindowForAll(int left, int top, int right, int bottom)
  */
 void Window::SetDirty() const
 {
-	SetDirtyBlocks(this->left, this->top, this->left + this->width, this->top + this->height);
+	AddDirtyBlock(this->left, this->top, this->left + this->width, this->top + this->height);
 }
 
 /**
@@ -3493,7 +3493,7 @@ static int PositionWindow(Window *w, WindowClass clss, int setting)
 		default: w->left = 0; break;
 	}
 	if (w->viewport != nullptr) w->viewport->left += w->left - old_left;
-	SetDirtyBlocks(0, w->top, _screen.width, w->top + w->height); // invalidate the whole row
+	AddDirtyBlock(0, w->top, _screen.width, w->top + w->height); // invalidate the whole row
 	return w->left;
 }