From f7a93f4cd35790e41e18e119c2cadaf223a73e71 Mon Sep 17 00:00:00 2001
From: Gleb Mazovetskiy <glex.spb@gmail.com>
Date: Sun, 10 Nov 2024 09:55:09 +0000
Subject: [PATCH] Improve `dev.display.path()`

1. Do not draw foliage with the pause trn.
2. Display the number of steps.
3. If the tile is not walkable (allowed for destination tile), display
   the number of steps in yellow.
---
 Source/engine/render/scrollrt.cpp | 32 ++++++++++++++++++++++++-------
 Source/player.cpp                 | 10 +++++-----
 Source/player.h                   |  4 ++--
 3 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/Source/engine/render/scrollrt.cpp b/Source/engine/render/scrollrt.cpp
index 271a9a9d58c..0e656c13888 100644
--- a/Source/engine/render/scrollrt.cpp
+++ b/Source/engine/render/scrollrt.cpp
@@ -477,9 +477,17 @@ void DrawCell(const Surface &out, Point tilePosition, Point targetBufferPosition
 	const MICROS *pMap = &DPieceMicros[levelPieceId];
 
 	const uint8_t *tbl = LightTables[lightTableIndex].data();
+	const uint8_t *foliageTbl = tbl;
 #ifdef _DEBUG
-	if (DebugPath && MyPlayer->IsPositionInPath(tilePosition))
-		tbl = GetPauseTRN();
+	int walkpathIdx = -1;
+	Point originalTargetBufferPosition;
+	if (DebugPath) {
+		walkpathIdx = MyPlayer->GetPositionPathIndex(tilePosition);
+		if (walkpathIdx != -1) {
+			originalTargetBufferPosition = targetBufferPosition;
+			tbl = GetPauseTRN();
+		}
+	}
 #endif
 
 	bool transparency = TileHasAny(tilePosition, TileProperties::Transparent) && TransList[dTransVal[tilePosition.x][tilePosition.y]];
@@ -529,7 +537,7 @@ void DrawCell(const Surface &out, Point tilePosition, Point targetBufferPosition
 		const TileType tileType = levelCelBlock.type();
 		if (!isFloor || tileType == TileType::TransparentSquare) {
 			if (isFloor && tileType == TileType::TransparentSquare) {
-				RenderTileFoliage(out, targetBufferPosition, levelCelBlock, tbl);
+				RenderTileFoliage(out, targetBufferPosition, levelCelBlock, foliageTbl);
 			} else {
 				RenderTile(out, targetBufferPosition, levelCelBlock, getFirstTileMaskLeft(tileType), tbl);
 			}
@@ -539,7 +547,7 @@ void DrawCell(const Surface &out, Point tilePosition, Point targetBufferPosition
 		const TileType tileType = levelCelBlock.type();
 		if (!isFloor || tileType == TileType::TransparentSquare) {
 			if (isFloor && tileType == TileType::TransparentSquare) {
-				RenderTileFoliage(out, targetBufferPosition + RightFrameDisplacement, levelCelBlock, tbl);
+				RenderTileFoliage(out, targetBufferPosition + RightFrameDisplacement, levelCelBlock, foliageTbl);
 			} else {
 				RenderTile(out, targetBufferPosition + RightFrameDisplacement,
 				    levelCelBlock, getFirstTileMaskRight(tileType), tbl);
@@ -554,7 +562,7 @@ void DrawCell(const Surface &out, Point tilePosition, Point targetBufferPosition
 			if (levelCelBlock.hasValue()) {
 				RenderTile(out, targetBufferPosition,
 				    levelCelBlock,
-				    transparency ? MaskType::Transparent : MaskType::Solid, tbl);
+				    transparency ? MaskType::Transparent : MaskType::Solid, foliageTbl);
 			}
 		}
 		{
@@ -562,11 +570,21 @@ void DrawCell(const Surface &out, Point tilePosition, Point targetBufferPosition
 			if (levelCelBlock.hasValue()) {
 				RenderTile(out, targetBufferPosition + RightFrameDisplacement,
 				    levelCelBlock,
-				    transparency ? MaskType::Transparent : MaskType::Solid, tbl);
+				    transparency ? MaskType::Transparent : MaskType::Solid, foliageTbl);
 			}
 		}
 		targetBufferPosition.y -= TILE_HEIGHT;
 	}
+
+#ifdef _DEBUG
+	if (DebugPath && walkpathIdx != -1) {
+		DrawString(out, StrCat(walkpathIdx),
+		    Rectangle(originalTargetBufferPosition + Displacement { 0, -TILE_HEIGHT }, Size { TILE_WIDTH, TILE_HEIGHT }),
+		    TextRenderOptions {
+		        .flags = UiFlags::AlignCenter | UiFlags::VerticalCenter
+		            | (IsTileSolid(tilePosition) ? UiFlags::ColorYellow : UiFlags::ColorWhite) });
+	}
+#endif
 }
 
 /**
@@ -581,7 +599,7 @@ void DrawFloorTile(const Surface &out, Point tilePosition, Point targetBufferPos
 
 	const uint8_t *tbl = LightTables[lightTableIndex].data();
 #ifdef _DEBUG
-	if (DebugPath && MyPlayer->IsPositionInPath(tilePosition))
+	if (DebugPath && MyPlayer->GetPositionPathIndex(tilePosition) != -1)
 		tbl = GetPauseTRN();
 #endif
 
diff --git a/Source/player.cpp b/Source/player.cpp
index 36eef40d5da..430b5f0451d 100644
--- a/Source/player.cpp
+++ b/Source/player.cpp
@@ -1653,21 +1653,21 @@ Point Player::GetTargetPosition() const
 	return target;
 }
 
-bool Player::IsPositionInPath(Point pos)
+int Player::GetPositionPathIndex(Point pos)
 {
 	constexpr Displacement DirectionOffset[8] = { { 0, -1 }, { -1, 0 }, { 1, 0 }, { 0, 1 }, { -1, -1 }, { 1, -1 }, { 1, 1 }, { -1, 1 } };
 	Point target = position.future;
+	int i = 0;
 	for (auto step : walkpath) {
-		if (target == pos) {
-			return true;
-		}
+		if (target == pos) return i;
 		if (step == WALK_NONE)
 			break;
 		if (step > 0) {
 			target += DirectionOffset[step - 1];
 		}
+		++i;
 	}
-	return false;
+	return -1;
 }
 
 void Player::Say(HeroSpeech speechId) const
diff --git a/Source/player.h b/Source/player.h
index 2a6a1d6b194..bbd4ac84a57 100644
--- a/Source/player.h
+++ b/Source/player.h
@@ -520,9 +520,9 @@ struct Player {
 	Point GetTargetPosition() const;
 
 	/**
-	 * @brief Check if position is in player's path.
+	 * @brief Returns the index of the given position in `walkpath`, or -1 if not found.
 	 */
-	bool IsPositionInPath(Point position);
+	int GetPositionPathIndex(Point position);
 
 	/**
 	 * @brief Says a speech line.