use bits for graphics buffer

5 files changed, 54 insertions, 35 deletions

diff --git a/src/chip8.cpp b/src/chip8.cpp
index 94573f0..485d061 100644
--- a/src/chip8.cpp
+++ b/src/chip8.cpp
@@ -168,9 +168,7 @@ void Chip8::OP_NULL() {}
 // 00E0: CLS
 // Clear the display
 void Chip8::OP_00E0() {
-  for (uint32_t i = 0; i < sizeof(video) / sizeof(video[0]); i++) {
-    video[i] = 0;
-  }
+  video.reset();
 };
 
 // 00EE: RET
@@ -385,29 +383,34 @@ void Chip8::OP_Cxkk() {
 // Dxyn: DRW Vx, Vy, nibble
 // Display n-byte sprite starting at memory location I at (Vx, Vy), set VF = collision
 void Chip8::OP_Dxyn() {
-  uint8_t Vx = (opcode & 0x0F00u) >> 8u;
-  uint8_t Vy = (opcode & 0x00FFu) >> 4u;
-  uint8_t height = opcode & 0x000Fu;
+    uint8_t Vx = (opcode & 0x0F00u) >> 8u;
+    uint8_t Vy = (opcode & 0x00F0u) >> 4u;
+    uint8_t height = opcode & 0x000Fu;
 
-  // Wrap if going beyond screen boundaries
-  uint8_t xPos = registers[Vx] % VIDEO_WIDTH;
-  uint8_t yPos = registers[Vy] % VIDEO_HEIGHT;
+    // Wrap if going beyond screen boundaries
+    uint8_t xPos = registers[Vx] % VIDEO_WIDTH;
+    uint8_t yPos = registers[Vy] % VIDEO_HEIGHT;
 
-  registers[0xF] = 0;
-
-  for (uint32_t row = 0; row < height; ++row) {
-    uint8_t spriteByte = memory[index + row];
-    for (uint32_t col = 0; col < 8; ++col) {
-      uint8_t spritePixel = spriteByte & (0x80u >> col);
-      uint32_t* screenPixel = &video[(yPos + row) * VIDEO_WIDTH + (xPos + col)];
+    registers[0xF] = 0;
 
-      if (spritePixel) {
-        if(*screenPixel == 0xFFFFFFFF)
-          registers[0xF] = 1;
-        *screenPixel ^= 0xFFFFFFFF;
-      }
+    for (uint32_t row = 0; row < height; ++row) {
+        uint8_t spriteByte = memory[index + row];
+        for (uint32_t col = 0; col < 8; ++col) {
+            uint8_t spritePixel = spriteByte & (0x80u >> col);
+
+            // Calculate the coordinates in the video bitset
+            int x = (xPos + col) % VIDEO_WIDTH;
+            int y = (yPos + row) % VIDEO_HEIGHT;
+
+            // Check collision and update the video bitset
+            if (spritePixel) {
+                if (video[y * VIDEO_WIDTH + x]) {
+                    registers[0xF] = 1;
+                }
+                video[y * VIDEO_WIDTH + x].flip();
+            }
+        }
     }
-  }
 }
 
 // Ex9E: SKP Vx
diff --git a/src/chip8.hpp b/src/chip8.hpp
index f144341..a2c4bdf 100644
--- a/src/chip8.hpp
+++ b/src/chip8.hpp
@@ -3,6 +3,7 @@
 
 #include <cstdint>
 #include <random>
+#include <bitset>
 
 const uint32_t VIDEO_HEIGHT = 32;
 const uint32_t VIDEO_WIDTH = 64;
@@ -24,7 +25,7 @@ class Chip8 {
     uint8_t soundTimer {};
 
     uint8_t keypad[16] {};
-    uint32_t video[VIDEO_WIDTH * VIDEO_HEIGHT] {};
+    std::bitset<4096> video; 
 
     uint16_t opcode;
 
diff --git a/src/main.cpp b/src/main.cpp
index b5f12df..0e60faa 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -24,7 +24,7 @@ int main(int argc, char** argv) {
   Chip8 chip8;
   chip8.LoadROM(filename);
 
-  int videoPitch = sizeof(chip8.video[0]) * VIDEO_WIDTH;
+  int count = 0;
 
   bool quit = false;
   while (!quit) {
@@ -33,7 +33,7 @@ int main(int argc, char** argv) {
     usleep(cycleDelay * 1000);
 
     chip8.Cycle();
-    platform.Update(chip8.video, videoPitch);
+    platform.Update(chip8.video, videoScale);
   }
 
   return 0;
diff --git a/src/platform.cpp b/src/platform.cpp
index c7d9ab3..2840fa1 100644
--- a/src/platform.cpp
+++ b/src/platform.cpp
@@ -1,25 +1,39 @@
+#include <bitset>
+
 #include "platform.hpp"
 
 Platform::Platform(const char* title, int windowWidth, int windowHeight, int textureWidth, int textureHeight) {
   SDL_Init(SDL_INIT_VIDEO);
   
-  window = SDL_CreateWindow(title, 0, 0, windowWidth, windowHeight, SDL_WINDOW_SHOWN);
+  window = SDL_CreateWindow(title, SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, windowWidth, windowHeight, SDL_WINDOW_SHOWN);
   renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
-  texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_STREAMING, textureWidth, textureHeight);
 }
 
 Platform::~Platform() {
-  SDL_DestroyTexture(texture);
   SDL_DestroyRenderer(renderer);
   SDL_DestroyWindow(window);
   SDL_Quit();
 }
 
-void Platform::Update(const void* buffer, int pitch) {
-  SDL_UpdateTexture(texture, nullptr, buffer, pitch);
-  SDL_RenderClear(renderer);
-  SDL_RenderCopy(renderer, texture, nullptr, nullptr);
-  SDL_RenderPresent(renderer);
+void Platform::Update(const std::bitset<4096>& bitset, int videoScale) {
+    SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
+    SDL_RenderClear(renderer);
+
+    for (int y = 0; y < 32; ++y) {
+        for (int x = 0; x < 64; ++x) {
+            SDL_Rect pixelRect = {x * videoScale, y * videoScale, videoScale, videoScale};
+
+            if (bitset[y * 64 + x]) {
+                SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
+            } else {
+                SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
+            }
+
+            SDL_RenderFillRect(renderer, &pixelRect);
+        }
+    }
+
+    SDL_RenderPresent(renderer);
 }
 
 bool Platform::ProcessInput(uint8_t* keys) {
diff --git a/src/platform.hpp b/src/platform.hpp
index 55b91df..90df65d 100644
--- a/src/platform.hpp
+++ b/src/platform.hpp
@@ -2,6 +2,8 @@
 #define PLATFORM_HPP_
 
 #include <cstdint>
+#include <bitset>
+
 #include <SDL.h>
 
 class Platform {
@@ -12,13 +14,12 @@ class Platform {
     ~Platform();
 
   public:
-    void Update(const void* buffer, int pitch);
+    void Update(const std::bitset<4096>& bitset, int videoScale);
     bool ProcessInput(uint8_t* keys);
 
   private:
     SDL_Window* window {};
     SDL_Renderer* renderer {};
-    SDL_Texture* texture {};
 };
 
 #endif