Script GUI: added TightGridLayout style (requirement of #1842)

The TightGridLayout fills spaces more aggressively. This is slower but makes for a tighter layout. Finding the best layout is NP-complete. This here is just O(N^2) or so.

docs/sdk/script/GUI.xml

@@ -178,6 +178,10 @@
 				<col>GUI_GridLayout</col>
 				<col>The sub-windows of this window will automatically be arranged in a grid.</col>
 			</row>
+			<row>
+				<col>GUI_TightGridLayout</col>
+				<col>Like GUI_GridLayout but might reorder items and lead to less empty space between sub-windows.</col>
+			</row>
 			<row>
 				<col>GUI_VerticalLayout</col>
 				<col>The sub-windows of this window will automatically be arranged vertically in a list.</col>

planet/Tests.ocf/MenuTest.ocs/Script.c

@@ -107,6 +107,7 @@ func StartMenu(plr)
 	menu->AddItem(Clonk, "Test Multiple Windows (Player List)", nil, Scenario, "StartPlayerListTest", "Shows how to display a permanent info dialogue.");
 	menu->AddItem(Lorry, "Tests Two Grid Menus (Trade Menu)", nil, Scenario, "StartTransferTest", "Shows how to work with two grid menus.");
 	menu->AddItem(Sproutberry, "Test HP Bars (HP Bars!)", nil, Scenario, "StartHPBarTest", "HP BARS!!!");
+	menu->AddItem(Crate, "Test mixed grid layout.", nil, Scenario, "StartMixedGridTest", "Grid menu with differently-sized items.");
 	
 	active_menu = GuiOpen(main_menu);
 }
@@ -459,4 +460,39 @@ func OnHPBarClose()
 	RemoveEffect("FoolAroundWithHPBar");
 	HP_bar_menu = nil;
 	Log("HP bar off!");
+}
+
+/* ------------------- mixed grid menu test ---------------*/
+func StartMixedGridTest()
+{
+	GuiClose(active_menu);
+	
+	var menu = 
+	{
+		toptext = {Bottom = "2em", Text="GUI_TightGridLayout", Style = GUI_TextHCenter},
+		top = {Top = "2em", Bottom = "50%", Margin = "0.5em", Style = GUI_TightGridLayout, Decoration = GUI_MenuDeco},
+		bottomtext = {Top = "50%", Bottom = "50% + 2em", Text="GUI_GridLayout", Style = GUI_TextHCenter}, 
+		bottom = {Top = "50% + 2em", Margin = "0.5em", Style = GUI_GridLayout, Decoration = GUI_MenuDeco},
+		BackgroundColor = RGBa(0, 0, 0, 128),
+	};
+	GuiAddCloseButton(menu, Scenario, "CloseCurrentMenu");
+	
+	var seed = 1;
+	for (var i=0; i < 50; ++i)
+	{
+		seed = ((seed * 17) + 7) % 1357;
+		var w = (seed % 4) + 1;
+		seed = ((seed * 23) + 13)% 1357;
+		var h = (seed % 4) + 1;
+		var item = 
+		{
+			Right = Format("%dem", w),
+			Bottom = Format("%dem", h),
+			Priority = i+1,
+			BackgroundColor = HSL(seed % 255, 200, 200)
+		};
+		GuiAddSubwindow(item, menu.top);
+		GuiAddSubwindow(item, menu.bottom);
+	}
+	active_menu = GuiOpen(menu);
 }

src/game/C4GameScript.cpp

@@ -3039,6 +3039,7 @@ C4ScriptConstDef C4ScriptGameConstMap[]=
 	{ "GUI_SetTag"               ,C4V_Int,      C4ScriptGuiWindowActionID::SetTag },
 	{ "GUI_Call"                 ,C4V_Int,      C4ScriptGuiWindowActionID::Call },
 	{ "GUI_GridLayout"           ,C4V_Int,      C4ScriptGuiWindowStyleFlag::GridLayout },
+	{ "GUI_TightGridLayout"      ,C4V_Int,      C4ScriptGuiWindowStyleFlag::TightGridLayout },
 	{ "GUI_VerticalLayout"       ,C4V_Int,      C4ScriptGuiWindowStyleFlag::VerticalLayout },
 	{ "GUI_TextVCenter"          ,C4V_Int,      C4ScriptGuiWindowStyleFlag::TextVCenter },
 	{ "GUI_TextHCenter"          ,C4V_Int,      C4ScriptGuiWindowStyleFlag::TextHCenter },

src/gui/C4ScriptGuiWindow.cpp

@@ -1445,6 +1445,91 @@ void C4ScriptGuiWindow::UpdateLayoutGrid()
 	EnableScrollBar(lowestChildRelY > height, lowestChildRelY);
 }
 
+// Similar to the grid layout but tries to fill spaces more thoroughly.
+// It's slower and might reorder items.
+void C4ScriptGuiWindow::UpdateLayoutTightGrid()
+{
+	const int32_t &width = rcBounds.Wdt;
+	const int32_t &height = rcBounds.Hgt;
+	const int32_t borderX(0), borderY(0);
+	int32_t lowestChildRelY = 0;
+
+	std::list<C4ScriptGuiWindow*> alreadyPlacedChildren;
+
+	for (C4GUI::Element * element : *this)
+	{
+		C4ScriptGuiWindow *child = static_cast<C4ScriptGuiWindow*>(element);
+		// calculate the space the child needs, correctly respecting the margins
+		const float childLeftMargin = child->CalculateRelativeSize(width, leftMargin, relLeftMargin);
+		const float childTopMargin = child->CalculateRelativeSize(height, topMargin, relTopMargin);
+		const float childRightMargin = child->CalculateRelativeSize(width, rightMargin, relRightMargin);
+		const float childBottomMargin = child->CalculateRelativeSize(height, bottomMargin, relBottomMargin);
+
+		const float childWdtF = float(child->rcBounds.Wdt) + childLeftMargin + childRightMargin;
+		const float childHgtF = float(child->rcBounds.Hgt) + childTopMargin + childBottomMargin;
+
+		// do all the rounding after the calculations
+		const int32_t childWdt = (int32_t)(childWdtF + 0.5f);
+		const int32_t childHgt = (int32_t)(childHgtF + 0.5f);
+
+		// Look for a free spot.
+		int32_t currentX = borderX;
+		int32_t currentY = borderY;
+
+		bool hadOverlap = false;
+		int overlapRepeats = 0;
+		do
+		{
+			auto overlapsWithOther = [&currentX, &currentY, &childWdt, &childHgt](C4ScriptGuiWindow *other)
+			{
+				if (currentX + childWdt <= other->rcBounds.x) return false;
+				if (currentY + childHgt <= other->rcBounds.y) return false;
+				if (currentX >= other->rcBounds.GetRight()) return false;
+				if (currentY >= other->rcBounds.GetBottom()) return false;
+				return true;
+			};
+
+			int32_t currentMinY = 0;
+			hadOverlap = false;
+			for (auto &other : alreadyPlacedChildren)
+			{
+				// Check if the other element is not yet above the new child.
+				if ((other->rcBounds.GetBottom() > currentY) && other->rcBounds.Hgt > 0)
+				{
+					if (currentMinY == 0 || (other->rcBounds.GetBottom() < currentMinY))
+						currentMinY = other->rcBounds.GetBottom();
+				}
+				// If overlapping, we must advance.
+				if (overlapsWithOther(other))
+				{
+					hadOverlap = true;
+					currentX = other->rcBounds.GetRight();
+					// Break line if the element doesn't fit anymore.
+					if (currentX + childWdt > width)
+					{
+						currentX = borderX;
+						// Start forcing change once we start repeating the check. Otherwise, there might
+						// be a composition of children that lead to infinite loop. The worst-case number
+						// of sensible checks might O(N^2) be with a really unfortunate children list.
+						const int32_t forcedMinimalChange = (overlapRepeats > alreadyPlacedChildren.size()) ? 1 : 0;
+						currentY = std::max(currentY + forcedMinimalChange, currentMinY);
+					}
+				}
+			}
+			overlapRepeats += 1;
+		} while (hadOverlap);
+
+		alreadyPlacedChildren.push_back(child);
+
+		lowestChildRelY = std::max(lowestChildRelY, currentY + childHgt);
+		child->rcBounds.x = currentX + static_cast<int32_t>(childLeftMargin);
+		child->rcBounds.y = currentY + static_cast<int32_t>(childTopMargin);
+	}
+
+	// do we need a scroll bar?
+	EnableScrollBar(lowestChildRelY > height, lowestChildRelY);
+}
+
 void C4ScriptGuiWindow::UpdateLayoutVertical()
 {
 	const int32_t borderY(0);
@@ -1738,6 +1823,8 @@ bool C4ScriptGuiWindow::UpdateLayout(C4TargetFacet &cgo, float parentWidth, floa
 	// special layout selected?
 	if (style & C4ScriptGuiWindowStyleFlag::GridLayout)
 		UpdateLayoutGrid();
+	else if (style & C4ScriptGuiWindowStyleFlag::TightGridLayout)
+		UpdateLayoutTightGrid();
 	else if (style & C4ScriptGuiWindowStyleFlag::VerticalLayout)
 		UpdateLayoutVertical();
 

src/gui/C4ScriptGuiWindow.h

@@ -82,7 +82,8 @@ enum C4ScriptGuiWindowStyleFlag
 	FitChildren = 64,
 	Multiple = 128,
 	IgnoreMouse = 256,
-	NoCrop = 512
+	NoCrop = 512,
+	TightGridLayout = 1024,
 };
 
 class C4ScriptGuiWindow;
@@ -291,6 +292,7 @@ public:
 	bool UpdateChildLayout(C4TargetFacet &cgo, float parentWidth, float parentHeight);
 	// special layouts that are set by styles
 	void UpdateLayoutGrid();
+	void UpdateLayoutTightGrid();
 	void UpdateLayoutVertical();
 	// the window will be drawn in the context of a viewport BY the viewport
 	// so just do nothing when TheScreen wants to draw the window