Some PPU code

CMakeLists.txt

@@ -16,7 +16,9 @@ add_executable(nes
         src/Mapper/Mapper.cpp
         src/Mapper/Mapper.h
         src/Mapper/Mapper0.cpp
-        src/Mapper/Mapper0.h src/Ppu.cpp src/Ppu.h)
+        src/Mapper/Mapper0.h src/Ppu.cpp src/Ppu.h
+        src/Window.cpp
+        src/Window.h)
 
 find_package(SDL2 CONFIG REQUIRED)
 target_link_libraries(nes PRIVATE SDL2::SDL2)

src/Bus.cpp

@@ -4,6 +4,7 @@
 
 #include "Bus.h"
 #include <iostream>
+#include <utility>
 
 namespace nes {
 
@@ -17,7 +18,7 @@ namespace nes {
         }
         else if(address >= 0x2000 && address < 0x4000) {
             std::cout << "PPU read at address: " << address << std::endl;
-            return 0;
+            return _ppu->read(address & 0x0007);
         }
         else if(address >= 0x8000) {
             return _cartridge->readPrg(address);
@@ -32,13 +33,18 @@ namespace nes {
         }
         else if(address >= 0x2000 && address < 0x4000) {
             std::cout << "PPU write at address: " << address << std::endl;
+            _ppu->write(address & 0x0007, value);
         }
         else if(address >= 0x8000) {
             std::cout << "Cartridge write at address: " << address << std::endl;
         }
     }
 
-    void Bus::connect(Cartridge *cartridge) {
+    void Bus::connect(std::shared_ptr<Cartridge> cartridge) {
-        _cartridge = cartridge;
+        _cartridge = std::move(cartridge);
+    }
+
+    void Bus::connect(std::shared_ptr<Ppu> ppu) {
+        _ppu = std::move(ppu);
     }
 }

src/Bus.h

@@ -6,6 +6,7 @@
 #define NES_BUS_H
 
 #include "Cartridge.h"
+#include "Ppu.h"
 
 #include <cstdint>
 #include <memory>
@@ -17,11 +18,13 @@ namespace nes {
         Bus();
         uint8_t read(uint16_t address);
         void write(uint16_t address, uint8_t value);
-        void connect(Cartridge* cartridge);
+        void connect(std::shared_ptr<Cartridge> cartridge);
+        void connect(std::shared_ptr<Ppu> ppu);
 
     private:
         std::unique_ptr<uint8_t[]> _ram;
-        Cartridge* _cartridge;
+        std::shared_ptr<Cartridge> _cartridge;
+        std::shared_ptr<Ppu> _ppu;
     };
 
 }

src/Nes.cpp

@@ -16,7 +16,8 @@ namespace nes {
 
     void Nes::runRom(const fs::path &path, std::optional<uint16_t> address) {
         _cartridge = std::make_shared<Cartridge>(path);
-        _cpu->bus()->connect(_cartridge.get());
+        _cpu->bus()->connect(_cartridge);
+        _cpu->bus()->connect(_ppu);
         reset(address);
     }
 

src/Ppu.cpp

@@ -7,11 +7,12 @@
 namespace nes {
 
     Ppu::Ppu(): _column{}, _scanline{} {
-
+        _frameBuffer = std::make_unique<Pixel[]>(SCREEN_WIDTH*SCREEN_HEIGHT);
     }
 
     void Ppu::tick() {
 
+        setPixel(_scanline, _column, {});
 
         _column++;
         if(_column >= 341) {
@@ -20,7 +21,21 @@ namespace nes {
 
             if(_scanline >= 261) {
                 _scanline = -1;
+                onNewFrame(_frameBuffer.get());
             }
         }
     }
+
+    void Ppu::write(uint16_t address, uint8_t value) {
+
+    }
+
+    uint8_t Ppu::read(uint16_t address) {
+        return 0;
+    }
+
+    void Ppu::setPixel(uint16_t row, uint16_t column, Pixel pixel) {
+        size_t index = row*SCREEN_WIDTH + column;
+        _frameBuffer[index] = pixel;
+    }
 }

src/Ppu.h

@@ -6,17 +6,37 @@
 #define NES_PPU_H
 
 #include <cstdint>
+#include <memory>
+#include <functional>
 
 namespace nes {
 
+    struct Pixel {
+        uint8_t R;
+        uint8_t G;
+        uint8_t B;
+        uint8_t A;
+    };
+
     class Ppu {
+    public:
+        static constexpr uint16_t SCREEN_WIDTH = 256;
+        static constexpr uint16_t SCREEN_HEIGHT = 240;
+
     public:
         Ppu();
         void tick();
+        void write(uint16_t address, uint8_t value);
+        uint8_t read(uint16_t address);
+        void setPixel(uint16_t row, uint16_t column, Pixel pixel);
+
+    public:
+        std::function<void(const Pixel*)> onNewFrame;
 
     private:
         int16_t _column;
         int16_t _scanline;
+        std::unique_ptr<Pixel[]> _frameBuffer;
     };
 
 }

src/Window.cpp

@@ -0,0 +1,9 @@
+//
+// Created by Мустафаев Селим Мустафаевич on 24.08.2023.
+//
+
+#include "Window.h"
+
+namespace nes {
+
+}

src/Window.h

@@ -0,0 +1,18 @@
+//
+// Created by Мустафаев Селим Мустафаевич on 24.08.2023.
+//
+
+#ifndef NES_WINDOW_H
+#define NES_WINDOW_H
+
+#include <SDL.h>
+
+namespace nes {
+
+    class Window {
+
+    };
+
+}
+
+#endif //NES_WINDOW_H