Need to walk back in memory and check the previous texture tiles to see if they overlap with the current textures being invalidated. If they overlap they must be cleared too. Algorithm is a bit brute forcy and more expensive than I'd like but it fixes the bad textures in Spikeout.

Src/Graphics/New3D/Texture.cpp

@@ -334,4 +334,19 @@ bool Texture::Compare(int x, int y, int width, int height, int format)
 	return false;
 }
 
+bool Texture::CheckMapPos(int ax1, int ax2, int ay1, int ay2)
+{
+	int bx1 = m_x;
+	int bx2 = m_x + m_width;
+	int by1 = m_y;
+	int by2 = m_y + m_height;
+
+	if (ax1<bx2 && ax2>bx1 &&
+		ay1<by2 && ay2>by1) {
+		return true;			// rectangles overlap
+	}
+
+	return false;
+}
+
 } // New3D

Src/Graphics/New3D/Texture.h

@@ -20,6 +20,7 @@ public:
 	void	GetDetails		(int& x, int&y, int& width, int& height, int& format);
 	void	SetWrapMode		(bool mirrorU, bool mirrorV);
 	bool	Compare			(int x, int y, int width, int height, int format);
+	bool	CheckMapPos		(int ax1, int ax2, int ay1, int ay2);				//check to see if textures overlap
 
 	static void GetCoordinates(int width, int height, UINT16 uIn, UINT16 vIn, float uvScale, float& uOut, float& vOut);
 

Src/Graphics/New3D/TextureSheet.cpp

@@ -75,30 +75,85 @@ void TextureSheet::Release()
 
 void TextureSheet::Invalidate(int x, int y, int width, int height)
 {
-	//==========
+	//============
+	int newX;
+	int newY;
+	int newWidth;
+	int newHeight;
 	int count;
 	int sWidth;		// sample width
 	int sHeight;	// sample height
-	//==========
+	//============
 
-	// since the smallest sized texture is 32x32 pixels?
-	// we can invalidate 32x32 tiles over the width/height of the area
+	if (width <= 512) {
+		newX = (x + width) - 512;
+		newWidth = 512;
+	}
+	else {
+		newX = x;
+		newWidth = width;
+	}
+	
+	if (height <= 512) {
+		newY = (y + height) - 512;
+		newHeight = 512;
+	}
+	else {
+		newY = y;
+		newHeight = height;
+	}
 
-	sWidth	= width / 32;
-	sHeight	= height / 32;
+	CropTile(x, y, newX, newY, newWidth, newHeight);
+
+	sWidth	= newWidth / 32;
+	sHeight = newHeight / 32;
 	count	= sWidth * sHeight;
 
 	for (int i = 0; i < count; i++) {
 
-		int index = ToIndex(x + ((i%sWidth) * 32), y + ((i / sWidth) * 32));
-
-		for (int j = 0; j<12; j++) {
-
-			if (m_texMap[j].count(index) > 0) {
+		int posX	= newX + ((i%sWidth) * 32);
+		int posY	= newY + ((i / sWidth) * 32);
+		int index	= ToIndex(posX, posY);
 
+		if (posX >= x && posY >= y) {				// invalidate this area of memory
+			for (int j = 0; j < 12; j++) {
 				m_texMap[j].erase(index);
 			}
 		}
+		else {										// check for overlapping data tiles and invalidate as necessary
+
+			for (int j = 0; j < 12; j++) {
+
+				auto range = m_texMap[j].equal_range(index);
+
+				for (auto it = range.first; it != range.second; ++it) {
+
+					if (it->second->CheckMapPos(x, x + width, y, y + height)) {
+						m_texMap[j].erase(index);
+						break;
+					}
+
+				}
+			}
+		}
+	}
+}
+
+void TextureSheet::CropTile(int oldX, int oldY, int &newX, int &newY, int &newWidth, int &newHeight)
+{
+	if (newX < 0) {
+		newWidth += newX;
+		newX = 0;
+	}
+
+	if (newY < 0) {
+		newHeight += newY;
+		newY = 0;
+	}
+
+	if (oldY >= 1024 && newY < 1024) {		// gone into next memory page, limitation of our flat model
+		newHeight -= 1024 - newY;
+		newY = 1024;
 	}
 }
 

Src/Graphics/New3D/TextureSheet.h

@@ -23,6 +23,7 @@ public:
 private:
 
 	int ToIndex(int x, int y);
+	void CropTile(int oldX, int oldY, int &newX, int &newY, int &newWidth, int &newHeight);
 
 	std::unordered_multimap<int, std::shared_ptr<Texture>> m_texMap[12];