First draft to show the nametable 0 in the debugger

Jonazan2 · Jan 2, 2020 · b7e0ae4 · b7e0ae4
1 parent e5bcb22
commit b7e0ae4
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Showing 7 changed files with 46 additions and 26 deletions.
diff --git a/Debugger/CpuDebugger.cpp b/Debugger/CpuDebugger.cpp
@@ -9,7 +9,7 @@
 CpuDebugger::CpuDebugger()
     : instructionJump( false )
 {
-    breakpoints.insert( 0xF109 );
+    breakpoints.insert( 0xF1CE );
 }
 
 void CpuDebugger::GenerateDisassemblerInstructionMask( Memory &memory )

diff --git a/Debugger/VideoDebugger.cpp b/Debugger/VideoDebugger.cpp
@@ -62,14 +62,12 @@ void VideoDebugger::CreateTextures( const Video &video )
 
 void VideoDebugger::ComposeView( u32 cycles, const Video &video, const Memory &memory )
 {
-    UpdatePatternTable( video, 0x0000, leftPatternTableBuffer );
-
     ImGui::SetNextWindowSize( ImVec2( 560, 510 ), ImGuiCond_FirstUseEver );
     ImGui::Begin( "FrameBuffer" );
     ImGui::Image( frameBufferTextureID, ImVec2( 512, 480 ) );
     ImGui::End();
 
-
+    UpdatePatternTable( video, 0x0000, leftPatternTableBuffer );
     ImGui::SetNextWindowSize( ImVec2( 560, 560 ), ImGuiCond_FirstUseEver );
     ImGui::Begin( "VRAM Left" );
     ImGui::Image( leftPatternTableTextureID, ImVec2( 512, 512 ) );
@@ -118,7 +116,7 @@ void VideoDebugger::ComposeView( u32 cycles, const Video &video, const Memory &m
     UpdateNameTable( video, memory, 0x2000, nametableTextureBuffer );
     ImGui::SetNextWindowSize( ImVec2( 560, 560 ), ImGuiCond_FirstUseEver );
     ImGui::Begin( "Nametable 0" );
-    ImGui::Image( nametableTextureBuffer, ImVec2( 512, 500 ) );
+    ImGui::Image( nametableTextureID, ImVec2( 512, 500 ) );
     ImGui::End();
 }
 
@@ -129,8 +127,8 @@ void VideoDebugger::UpdatePatternTable( const Video &video, word address, RGB *b
     assert( ppuMemory != nullptr );
 
     u32 vramPosition = 0;
-    for ( u32 tile = 0; tile < 256; ++tile )
-    {
+    for ( u32 tile = 0; tile < Video::NES_PATTERN_TILE_AMOUNT; ++tile )
+    { 
         const u32 tileAddress = ( tile * 0x10 ) + address;
 
         u32 localvramPosition = vramPosition;
@@ -146,7 +144,7 @@ void VideoDebugger::UpdatePatternTable( const Video &video, word address, RGB *b
                 const byte value2 = ( firstByte & mask ) >> column;
                 const byte finalValue = value | value2;
 
-                buffer[ localvramPosition + ( 7 - column ) ] = palette[ finalValue ];
+                buffer[ localvramPosition + ( 7 - column ) ] = NES_PALETTE_COLORS[ palette[ finalValue ] ];
             }
             localvramPosition += 128;
         }
@@ -183,7 +181,7 @@ void VideoDebugger::UpdateTexturesOfCurrentPalettes( const Video &video, word ad
     assert( ppuMemory != nullptr );
     assert( buffer != nullptr );
 
-    u32 paletteAddress = address;
+    word paletteAddress = address;
     for ( byte index = 0; index < 4; ++index )
     {
         for ( byte i = 0; i < 3; ++i )
@@ -198,6 +196,7 @@ void VideoDebugger::UpdateTexturesOfCurrentPalettes( const Video &video, word ad
 
 void VideoDebugger::UpdateNameTable( const Video &video, const Memory &memory, word nametableAddress, RGB *buffer )
 {
+    /* We use the mal directly since reading some of the values in the map through memory.Read() has side effects */
     const byte *const memoryMap = memory.GetMemoryMap();
     assert( memoryMap != nullptr );
 
@@ -207,15 +206,15 @@ void VideoDebugger::UpdateNameTable( const Video &video, const Memory &memory, w
 
     /* Traverse the nametable and construct the background */
     u32 initialAddress = nametableAddress;
-    for ( u32 row = 0; row < 30; ++row )
+    for ( u32 row = 0; row < Video::NES_VIDEO_HEIGHT; ++row )
     {
-        for ( u32 column = 0; column < 32; ++column )
+        for ( u32 column = 0; column < Video::NES_VIDEO_WIDTH; ++column )
         {
             const byte tileOffset = video.Read( nametableAddress );
             ++nametableAddress;
 
             /* Update the background buffer */
-            const byte tileAddress = patternTableAddress + tileOffset;
+            const u32 tileAddress = patternTableAddress + tileOffset;
             u32 localvramPosition = tileAddress;
             for ( byte tileRow = 0; tileRow < 8; ++tileRow )
             {
@@ -224,12 +223,13 @@ void VideoDebugger::UpdateNameTable( const Video &video, const Memory &memory, w
 
                 for ( byte tileColumn = 0; tileColumn < 8; ++tileColumn )
                 {
-                    byte mask = 0x01 << tileColumn;
+                    const byte mask = 0x01 << tileColumn;
                     const byte value = ( ( secondByte & mask ) >> tileColumn )  << 1;
                     const byte value2 = ( firstByte & mask ) >> tileColumn;
                     const byte finalValue = value | value2;
 
-                    buffer[ localvramPosition + ( 7 - tileColumn ) ] = palette[ finalValue ];
+                    const u32 textureIndex = column + row * Video::NES_VIDEO_WIDTH; 
+                    buffer[ textureIndex ] = NES_PALETTE_COLORS[ palette[ finalValue ] ];
                 }
                 localvramPosition += 128;
             }

diff --git a/Debugger/VideoDebugger.h b/Debugger/VideoDebugger.h
@@ -15,8 +15,8 @@ class VideoDebugger
     void ComposeView( u32 cycles, const Video &video, const Memory &memory );
 
 private:
-    constexpr static RGB palette[4] = { { 255,255,255 },{ 0xCC,0xCC,0xCC },{ 0x77,0x77,0x77 }, { 0x0,0x0,0x0 } };
-
+    constexpr static byte palette[4] = { 0x0F, 0x2C, 0x38, 0x12 };
+ 
     using ImTextureID = void *;
 
     /* Textures */
@@ -43,10 +43,10 @@ class VideoDebugger
     ImTextureID     nametableTextureID;
     RGB             *nametableTextureBuffer;
 
-
     void UpdatePatternTable( const Video &video, word address, RGB *buffer );
     void GenerateNesPaletteTexture();
     void UpdateUniversalBackgroundColour( const Video &video );
     void UpdateTexturesOfCurrentPalettes( const Video &video, word address, RGB **buffer );
     void UpdateNameTable( const Video &video, const Memory &memory, word nametableAddress, RGB *buffer );
+    void DrawTile( RGB *buffer );
 };
diff --git a/Memory.cpp b/Memory.cpp
@@ -78,10 +78,8 @@ void Memory::Write( word address, byte data )
     if ( address >= 0x2000 && address <= 0x3FFF )
     {
         const word ppuRegister = ( address % 8 ) + 0x2000;
-        if ( ppuRegister == Video::PPUDATA_ADDRESS )
+        if ( ppuRegister == Video::PPUADDR_REGISTER )
         {
-            const word address = map[ Video::PPUADDR_REGISTER ];
-
             if ( IsAddressLatchClear )
             {
                 IsAddressLatchClear = false;
@@ -91,11 +89,24 @@ void Memory::Write( word address, byte data )
             {
                 currentVRamAddress = data | currentVRamAddress;
             }
-            map[ Video::PPUDATA_ADDRESS ] = data;
+            map[ Video::PPUADDR_REGISTER ] = data;
+
+        }
+        else if ( ppuRegister == Video::PPUDATA_ADDRESS )
+        {
+            const word address = currentVRamAddress;
+            video->Write( address, data );
 
             const byte ppuControlRegister = map[ Video::PPUCTRL_REGISTER ];
-            const byte incrementAmount = ( ppuControlRegister | 0b0000'0100 ) >> 2;
-            map[ Video::PPUADDR_REGISTER ] = incrementAmount;
+            const byte incrementType = ( ppuControlRegister & 0b0000'0100 ) >> 2;
+            if ( incrementType == 0 )
+            {
+                currentVRamAddress++;
+            }
+            else
+            {
+                currentVRamAddress += 32;
+            }
         }
         else
         {

diff --git a/Types.h b/Types.h
@@ -33,7 +33,10 @@ struct RGB
     }
 };
 
-constexpr RGB PINK = { 0xFF, 0x00, 0x80 };
+namespace color
+{
+    constexpr RGB PINK = { 0xFF, 0x00, 0x80 };
+}
 
 
 /* Operators */

diff --git a/Video.cpp b/Video.cpp
@@ -28,7 +28,7 @@ void Video::Reset()
 
     for ( u32 i = 0; i < NES_VIDEO_RESOLUTION; ++i )
     {
-        frameBuffer[ i ] = PINK;
+        frameBuffer[ i ] = color::PINK;
     }
 
     MapCartridgeCHRToPPU();

diff --git a/Video.h b/Video.h
@@ -48,7 +48,13 @@ class Video
 {
 public:
 
-    static constexpr u32 NES_VIDEO_RESOLUTION = 256 * 240;
+    /* NES frame buffer constants */
+    static constexpr u32 NES_VIDEO_WIDTH = 256;
+    static constexpr u32 NES_VIDEO_HEIGHT = 240;
+    static constexpr u32 NES_VIDEO_RESOLUTION = NES_VIDEO_HEIGHT * NES_VIDEO_WIDTH;
+
+    /* NES tiles and objects constants */
+    static constexpr u32 NES_PATTERN_TILE_AMOUNT = 256;
 
     /* PPU Register addresses */
     static constexpr word PPUCTRL_REGISTER      = 0x2000;