Enginify `trans_rect`

Moves `trans_rect` to `engine` as `DrawHalfTransparentRectTo` and makes
it operate on `CelOutputBuf`.

Source/automap.cpp

@@ -618,19 +618,13 @@ static void DrawAutomapText(CelOutputBuffer out)
 	}
 }
 
-/**
- * @brief Renders the automap on screen.
- */
-void DrawAutomap()
+void DrawAutomap(CelOutputBuffer out)
 {
 	int cells;
 	int sx, sy;
 	int i, j, d;
 	int mapx, mapy;
 
-	CelOutputBuffer out = GlobalBackBuffer();
-	out = out.subregion(0, 0, out.line_width, SCREEN_Y + VIEWPORT_HEIGHT);
-
 	if (leveltype == DTYPE_TOWN) {
 		DrawAutomapText(out);
 		return;

Source/automap.h

@@ -6,6 +6,8 @@
 #ifndef __AUTOMAP_H__
 #define __AUTOMAP_H__
 
+#include "engine.h"
+
 DEVILUTION_BEGIN_NAMESPACE
 
 #ifdef __cplusplus
@@ -32,7 +34,12 @@ void AutomapLeft();
 void AutomapRight();
 void AutomapZoomIn();
 void AutomapZoomOut();
-void DrawAutomap();
+
+/**
+ * @brief Renders the automap to the given buffer.
+ */
+void DrawAutomap(CelOutputBuffer out);
+
 void SetAutomapView(int x, int y);
 void AutomapZoomReset();
 

Source/engine.cpp

@@ -555,6 +555,43 @@ void DrawLineTo(CelOutputBuffer out, int x0, int y0, int x1, int y1, BYTE color_
 	}
 }
 
+static void DrawHalfTransparentBlendedRectTo(CelOutputBuffer out, int sx, int sy, int width, int height)
+{
+	BYTE *pix = out.at(sx, sy);
+	for (int row = 0; row < height; row++) {
+		for (int col = 0; col < width; col++) {
+			*pix = paletteTransparencyLookup[0][*pix];
+			pix++;
+		}
+		pix += out.line_width - width;
+	}
+}
+
+static void DrawHalfTransparentStippledRectTo(CelOutputBuffer out, int sx, int sy, int width, int height)
+{
+	BYTE *pix = out.at(sx, sy);
+	for (int row = 0; row < height; row++) {
+		for (int col = 0; col < width; col++) {
+			if ((row & 1 && col & 1) || (!(row & 1) && !(col & 1)))
+				*pix = 0;
+			pix++;
+		}
+		pix += out.line_width - width;
+	}
+}
+
+void DrawHalfTransparentRectTo(CelOutputBuffer out, int sx, int sy, int width, int height)
+{
+	int row, col;
+	BYTE *pix = out.at(sx, sy);
+
+	if (sgOptions.bBlendedTransparancy) {
+		DrawHalfTransparentBlendedRectTo(out, sx, sy, width, height);
+	} else {
+		DrawHalfTransparentStippledRectTo(out, sx, sy, width, height);
+	}
+}
+
 int GetDirection(int x1, int y1, int x2, int y2)
 {
 	int mx, my;

Source/engine.h

@@ -341,6 +341,23 @@ void Cl2DrawLight(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth);
  */
 void DrawLineTo(CelOutputBuffer out, int x0, int y0, int x1, int y1, BYTE color_index);
 
+
+/**
+ * Draws a half-transparent rectangle by blacking out odd pixels on odd lines,
+ * even pixels on even lines.
+ *
+ * If blended transparency is enabled, uses `paletteTransparencyLookup` table instead
+ * of blacking pixels out.
+ *
+ * @brief Render a transparent black rectangle
+ * @param out Target buffer
+ * @param sx Screen coordinate
+ * @param sy Screen coordinate
+ * @param width Rectangle width
+ * @param height Rectangle height
+ */
+void DrawHalfTransparentRectTo(CelOutputBuffer out, int sx, int sy, int width, int height);
+
 /**
  * @brief Calculate the best fit direction between two points
  * @param x1 Tile coordinate

Source/error.cpp

@@ -126,7 +126,7 @@ void DrawDiabloMsg()
 
 	assert(gpBuffer);
 
-	trans_rect(PANEL_LEFT + 104, DIALOG_TOP - 8, 432, 54);
+	DrawHalfTransparentRectTo(GlobalBackBuffer(), PANEL_LEFT + 104, DIALOG_TOP - 8, 432, 54);
 
 	strcpy(tempstr, MsgStrings[msgflag]);
 	sx = PANEL_X + 101;

Source/help.cpp

@@ -468,14 +468,14 @@ static void DrawHelpLine(int x, int y, char *text, char color)
 	}
 }
 
-void DrawHelp()
+void DrawHelp(CelOutputBuffer out)
 {
 	int i, c, w;
 	char col;
 	const char *s;
 
 	DrawSTextHelp();
-	DrawQTextBack();
+	DrawQTextBack(out);
 	if (gbIsHellfire)
 		PrintSString(0, 2, TRUE, "Hellfire Help", COL_GOLD, 0);
 	else

Source/help.h

@@ -15,7 +15,7 @@ extern "C" {
 extern BOOL helpflag;
 
 void InitHelp();
-void DrawHelp();
+void DrawHelp(CelOutputBuffer out);
 void DisplayHelp();
 void HelpScrollUp();
 void HelpScrollDown();

Source/items.cpp

@@ -3954,10 +3954,10 @@ void PrintItemPower(char plidx, ItemStruct *x)
 	}
 }
 
-void DrawUTextBack()
+static void DrawUTextBack(CelOutputBuffer out)
 {
-	CelDraw(RIGHT_PANEL_X - SPANEL_WIDTH + 24, SCREEN_Y + 327, pSTextBoxCels, 1, 271);
-	trans_rect(RIGHT_PANEL - SPANEL_WIDTH + 27, 28, 265, 297);
+	CelDrawTo(out, RIGHT_PANEL_X - SPANEL_WIDTH + 24, SCREEN_Y + 327, pSTextBoxCels, 1, 271);
+	DrawHalfTransparentRectTo(out, RIGHT_PANEL - SPANEL_WIDTH + 27, 28, 265, 297);
 }
 
 void PrintUString(int x, int y, BOOL cjustflag, const char *str, int col)
@@ -4008,7 +4008,7 @@ void DrawUniqueInfo()
 
 	if ((!chrflag && !questlog) || SCREEN_WIDTH >= SPANEL_WIDTH * 3) {
 		uid = curruitem._iUid;
-		DrawUTextBack();
+		DrawUTextBack(GlobalBackBuffer());
 		PrintUString(0 + RIGHT_PANEL - SPANEL_WIDTH, 2, TRUE, UniqueItemList[uid].UIName, 3);
 		DrawULine(5);
 		PrintItemPower(UniqueItemList[uid].UIPower1, &curruitem);

Source/minitext.cpp

@@ -172,8 +172,9 @@ void ScrollQTextContent(const char *pnl)
 /**
  * @brief Draw the current text in the quest dialog window
  */
-void DrawQTextContent()
+static void DrawQTextContent(CelOutputBuffer out)
 {
+	// TODO: Draw to the given `out` buffer.
 	const char *text, *pnl;
 	char line[128];
 
@@ -247,22 +248,16 @@ void InitQTextMsg(int m)
 	PlaySFX(alltext[m].sfxnr);
 }
 
-/**
- * @brief Draw the quest dialog window decoration and background
- */
-void DrawQTextBack()
+void DrawQTextBack(CelOutputBuffer out)
 {
-	CelDraw(PANEL_X + 24, SCREEN_Y + 327 + UI_OFFSET_Y, pTextBoxCels, 1, 591);
-	trans_rect(PANEL_LEFT + 27, UI_OFFSET_Y + 28, 585, 297);
+	CelDrawTo(out, PANEL_X + 24, SCREEN_Y + 327 + UI_OFFSET_Y, pTextBoxCels, 1, 591);
+	DrawHalfTransparentRectTo(out, PANEL_LEFT + 27, UI_OFFSET_Y + 28, 585, 297);
 }
 
-/**
- * @brief Draw the quest dialog window decoration and background
- */
-void DrawQText()
+void DrawQText(CelOutputBuffer out)
 {
-	DrawQTextBack();
-	DrawQTextContent();
+	DrawQTextBack(out);
+	DrawQTextContent(out);
 }
 
 DEVILUTION_END_NAMESPACE

Source/minitext.h

@@ -17,8 +17,16 @@ extern bool qtextflag;
 void FreeQuestText();
 void InitQuestText();
 void InitQTextMsg(int m);
-void DrawQTextBack();
-void DrawQText();
+
+/**
+ * @brief Draw the quest dialog window decoration and background.
+ */
+void DrawQTextBack(CelOutputBuffer out);
+
+/**
+ * @brief Draw the quest dialog window text.
+ */
+void DrawQText(CelOutputBuffer out);
 
 #ifdef __cplusplus
 }

Source/render.cpp

@@ -601,39 +601,4 @@ void world_draw_black_tile(int sx, int sy)
 	}
 }
 
-/**
- * Draws a half-transparent rectangle by blacking out odd pixels on odd lines,
- * even pixels on even lines.
- * @brief Render a transparent black rectangle
- * @param sx Screen coordinate
- * @param sy Screen coordinate
- * @param width Rectangle width
- * @param height Rectangle height
- */
-void trans_rect(int sx, int sy, int width, int height)
-{
-	int row, col;
-	BYTE *pix = &gpBuffer[SCREENXY(sx, sy)];
-
-	if (sgOptions.bBlendedTransparancy) { // Blended
-		for (row = 0; row < height; row++) {
-			for (col = 0; col < width; col++) {
-				*pix = paletteTransparencyLookup[0][*pix];
-				pix++;
-			}
-			pix += BUFFER_WIDTH - width;
-		}
-		return;
-	}
-
-	for (row = 0; row < height; row++) {
-		for (col = 0; col < width; col++) {
-			if ((row & 1 && col & 1) || (!(row & 1) && !(col & 1))) // Stippled
-				*pix = 0;
-			pix++;
-		}
-		pix += BUFFER_WIDTH - width;
-	}
-}
-
 DEVILUTION_END_NAMESPACE

Source/render.h

@@ -14,7 +14,6 @@ extern "C" {
 
 void RenderTile(BYTE *pBuff);
 void world_draw_black_tile(int sx, int sy);
-void trans_rect(int sx, int sy, int width, int height);
 
 #ifdef __cplusplus
 }

Source/scrollrt.cpp

@@ -1226,12 +1226,14 @@ extern void DrawControllerModifierHints();
  */
 void DrawView(int StartX, int StartY)
 {
+	CelOutputBuffer out = GlobalBackBuffer();
+
 	DrawGame(StartX, StartY);
 	if (automapflag) {
-		DrawAutomap();
+		DrawAutomap(out.subregion(0, 0, out.line_width, SCREEN_Y + VIEWPORT_HEIGHT));
 	}
 	if (stextflag && !qtextflag)
-		DrawSText();
+		DrawSText(out);
 	if (invflag) {
 		DrawInv();
 	} else if (sbookflag) {
@@ -1253,7 +1255,7 @@ void DrawView(int StartX, int StartY)
 		DrawUniqueInfo();
 	}
 	if (qtextflag) {
-		DrawQText();
+		DrawQText(out);
 	}
 	if (spselflag) {
 		DrawSpellList();
@@ -1262,7 +1264,7 @@ void DrawView(int StartX, int StartY)
 		DrawGoldSplit(dropGoldValue);
 	}
 	if (helpflag) {
-		DrawHelp();
+		DrawHelp(out);
 	}
 	if (msgflag) {
 		DrawDiabloMsg();

Source/stores.cpp

@@ -118,10 +118,10 @@ void FreeStoreMem()
 	MemFreeDbg(pSTextSlidCels);
 }
 
-void DrawSTextBack()
+static void DrawSTextBack(CelOutputBuffer out)
 {
-	CelDraw(PANEL_X + 344, 327 + SCREEN_Y + UI_OFFSET_Y, pSTextBoxCels, 1, 271);
-	trans_rect(PANEL_LEFT + 347, UI_OFFSET_Y + 28, 265, 297);
+	CelDrawTo(out, PANEL_X + 344, 327 + SCREEN_Y + UI_OFFSET_Y, pSTextBoxCels, 1, 271);
+	DrawHalfTransparentRectTo(out, PANEL_LEFT + 347, UI_OFFSET_Y + 28, 265, 297);
 }
 
 void PrintSString(int x, int y, BOOL cjustflag, const char *str, char col, int val)
@@ -1575,14 +1575,14 @@ void StartStore(char s)
 	}
 }
 
-void DrawSText()
+void DrawSText(CelOutputBuffer out)
 {
 	int i;
 
 	if (!stextsize)
-		DrawSTextBack();
+		DrawSTextBack(out);
 	else
-		DrawQTextBack();
+		DrawQTextBack(out);
 
 	if (stextscrl) {
 		switch (stextflag) {

Source/stores.h

@@ -46,7 +46,7 @@ void DrawSLine(int y);
 void DrawSTextHelp();
 void ClearSText(int s, int e);
 void StartStore(char s);
-void DrawSText();
+void DrawSText(CelOutputBuffer out);
 void STextESC();
 void STextUp();
 void STextDown();