starting the renderMainandSubScreen fct

sources/PPU/Background.cpp

@@ -9,7 +9,8 @@
 namespace ComSquare::PPU
 {
 	Background::Background(ComSquare::PPU::PPU &_ppu, int bgNumber, bool priority):
-		_priority(priority)
+		priority(priority),
+		bgNumber(bgNumber)
 	{
 		_cgram = _ppu.cgram;
 		_vram = _ppu.vram;
@@ -27,8 +28,8 @@ namespace ComSquare::PPU
 	{
 		uint16_t vramAddress = this->_TileMapStartAddress;
 		Vector2<int> offset(0, 0);
-		this->_backgroundSize.x = this->_tileMaps.x * this->_characterSize.x * 32;
-		this->_backgroundSize.y = this->_tileMaps.y * this->_characterSize.y * 32;
+		this->backgroundSize.x = this->_tileMaps.x * this->_characterSize.x * 32;
+		this->backgroundSize.y = this->_tileMaps.y * this->_characterSize.y * 32;
 
 		for (int i = 0; i < 4; i++) {
 			if (!(i == 1 && this->_tileMaps.x == 1) && !(i > 1 && this->_tileMaps.y == 1)) {
@@ -59,7 +60,8 @@ namespace ComSquare::PPU
 				palette = getPalette(tileData.palette);
 				reference = getTilePixelReference(graphicAddress, index);
 				color = getRealColor(palette[reference]);
-				this->_buffer[pos.x][pos.y] = color;
+				if (tileData.tilePriority == this->priority)
+					this->buffer[pos.x][pos.y] = color;
 				index++;
 				pos.x++;
 				if (index == (8 / this->_bpp) - 1) {

sources/PPU/Background.hpp

@@ -22,7 +22,6 @@ namespace ComSquare::PPU
 		int _bpp;
 		bool _directColor;
 		bool _highRes;
-		bool _priority;
 		uint16_t _TileMapStartAddress;
 		uint16_t _tileSetAddress;
 
@@ -39,8 +38,10 @@ namespace ComSquare::PPU
 		//! @brief draw a tilemap 32x32 starting at baseAddress
 		void drawBasicTileMap(uint16_t baseAddress, Vector2<int> offset);
 	public:
-		Vector2<int> _backgroundSize;
-		std::array<std::array<uint32_t, 1024>, 1024> _buffer;
+		bool priority;
+		int bgNumber;
+		Vector2<int> backgroundSize;
+		std::array<std::array<uint32_t, 1024>, 1024> buffer;
 		Background(ComSquare::PPU::PPU &_ppu, int bgNumber, bool priority);
 		//! @brief Render a background on the screen
 		void renderBackground(void);

sources/PPU/PPU.cpp

@@ -253,9 +253,9 @@ namespace ComSquare::PPU
 		(void)cycles;
 
 		this->_backgrounds[0].renderBackground();
-		for (int i = 0; i < this->_backgrounds[0]._backgroundSize.y; i++) {
-			for (int j = 0; j < this->_backgrounds[0]._backgroundSize.x; j++) {
-				this->_renderer.putPixel(j, i, this->_backgrounds[0]._buffer[i][j]);
+		for (int i = 0; i < this->_backgrounds[0].backgroundSize.y; i++) {
+			for (int j = 0; j < this->_backgrounds[0].backgroundSize.x; j++) {
+				this->_renderer.putPixel(j, i, this->_backgrounds[0].buffer[i][j]);
 			}
 		}
 		this->_renderer.drawScreen();
@@ -483,4 +483,49 @@ namespace ComSquare::PPU
 		backgroundSize.x = (this->_registers._bgsc[bgNumber - 1].tilemapHorizontalMirroring) ? 2 : 1;
 		return backgroundSize;
 	}
+
+	void PPU::renderMainAndSubScreen(void)
+	{
+		for (auto & _background : this->_backgrounds)
+			_background.renderBackground();
+
+		// the buffer is overwrite if necessery by a new bg so the background priority is from back to front
+		switch (this->_registers._bgmode.bgMode) {
+		case 0:
+			this->addToMainSubScreen(this->_backgrounds[bgName::bg4NoPriority]);
+			this->addToMainSubScreen(this->_backgrounds[bgName::bg3NoPriority]);
+			//sprites  priority 0
+			this->addToMainSubScreen(this->_backgrounds[bgName::bg4Priority]);
+			this->addToMainSubScreen(this->_backgrounds[bgName::bg3Priority]);
+			//sprites priority 1
+			this->addToMainSubScreen(this->_backgrounds[bgName::bg2NoPriority]);
+			this->addToMainSubScreen(this->_backgrounds[bgName::bg1NoPriority]);
+			//sprites priority 2
+			this->addToMainSubScreen(this->_backgrounds[bgName::bg2Priority]);
+			this->addToMainSubScreen(this->_backgrounds[bgName::bg1Priority]);
+			//sprites priority 3
+			break;
+		}
+	}
+
+	template <std::size_t SIZE>
+	void PPU::add_buffer(std::array<std::array<uint32_t, SIZE>, SIZE> &buffer, Background &bg)
+	{
+		for (int i = 0; i < bg.backgroundSize.y; i++) {
+			for (int j = 0; j < bg.backgroundSize.x; j++) {
+				if (bg.buffer[i][j])
+					buffer[i][j] = bg.buffer[i][j];
+			}
+		}
+	}
+
+	void PPU::addToMainSubScreen(Background &bg)
+	{
+		int i = bg.bgNumber + bg.priority;
+
+		if (this->_registers._t[0].raw & (1U << bg.bgNumber - 1U))
+			this->add_buffer(this->_mainScreen, this->_backgrounds[i]);
+		if (this->_registers._t[1].raw & (1U << bg.bgNumber - 1U))
+			this->add_buffer(this->_subScreen, this->_backgrounds[i]);
+	}
 }

sources/PPU/PPU.hpp

@@ -21,6 +21,17 @@
 namespace ComSquare::PPU
 {
 	class Background;
+	enum bgName {
+		bg1NoPriority = 0,
+		bg1Priority,
+		bg2NoPriority,
+		bg2Priority,
+		bg3NoPriority,
+		bg3Priority,
+		bg4NoPriority,
+		bg4Priority
+	};
+
 	enum ppuRegisters {
 	//! @brief INIDISP Register (F-blank and Brightness)
 	inidisp = 0x00,
@@ -605,6 +616,13 @@ namespace ComSquare::PPU
 		uint16_t getTileSetAddress(int bgNumber);
 		//! @brief Give the number of tilemaps to be rendered
 		Vector2<int> getBackgroundSize(int bgNumber);
+		//! @brief Render the Main and sub screen correctly
+		void renderMainAndSubScreen(void);
+		//! @brief Add a bg buffer to another buffer
+		template <std::size_t SIZE>
+		void PPU::add_buffer(std::array<std::array<uint32_t, SIZE>, SIZE> &buffer, Background &bg);
+		//! @brief Add a bg to the sub and/or main screen
+		void addToMainSubScreen(Background &bg);
 	};
 }
 #endif //COMSQUARE_PPU_HPP