Added VRAM Viewer and tried to fix noise channel

2026-05-15 16:34:34 +01:00
parent 787e403232
commit f52a5cbfdb
6 changed files with 227 additions and 96 deletions
--- a/Desktop/VramViewerForm.cs
+++ b/Desktop/VramViewerForm.cs
@@ -0,0 +1,100 @@
+using System;
+using System.Drawing;
+using System.Drawing.Imaging;
+using System.Runtime.InteropServices;
+using System.Windows.Forms;
+using Core.Video;
+
+namespace Desktop
+{
+    public class VramViewerForm : Form
+    {
+        private readonly SmsVdp _vdp;
+        private readonly System.Windows.Forms.Timer _refreshTimer;
+        private readonly Bitmap _vramBitmap;
+        private readonly int[] _pixelData;
+
+        public VramViewerForm(SmsVdp vdp)
+        {
+            _vdp = vdp;
+            this.Text = "VRAM Viewer (512 Tiles)";
+
+            // 256x128 native resolution, scaled up by 2 for visibility!
+            this.ClientSize = new Size(512, 256);
+            this.DoubleBuffered = true;
+            this.FormBorderStyle = FormBorderStyle.FixedToolWindow;
+
+            _vramBitmap = new Bitmap(256, 128, PixelFormat.Format32bppArgb);
+            _pixelData = new int[256 * 128];
+
+            // Update the window 10 times a second so it doesn't drain CPU power
+            _refreshTimer = new System.Windows.Forms.Timer();
+            _refreshTimer.Interval = 100;
+            _refreshTimer.Tick += (s, e) => UpdateVramImage();
+            _refreshTimer.Start();
+        }
+
+        private void UpdateVramImage()
+        {
+            if (_vdp == null) return;
+
+            // Loop through all 512 tiles in VRAM
+            for (int tile = 0; tile < 512; tile++)
+            {
+                // Calculate grid position (32 columns, 16 rows)
+                int tileX = (tile % 32) * 8;
+                int tileY = (tile / 32) * 8;
+                int tileAddress = tile * 32;
+
+                // Decode the 8x8 pixels
+                for (int y = 0; y < 8; y++)
+                {
+                    byte bp0 = _vdp.VRAM[tileAddress + (y * 4) + 0];
+                    byte bp1 = _vdp.VRAM[tileAddress + (y * 4) + 1];
+                    byte bp2 = _vdp.VRAM[tileAddress + (y * 4) + 2];
+                    byte bp3 = _vdp.VRAM[tileAddress + (y * 4) + 3];
+
+                    for (int x = 0; x < 8; x++)
+                    {
+                        int shift = 7 - x;
+                        int colorIndex = ((bp0 >> shift) & 1) | (((bp1 >> shift) & 1) << 1) |
+                                         (((bp2 >> shift) & 1) << 2) | (((bp3 >> shift) & 1) << 3);
+
+                        // Use the Sprite Palette (Offset 16) so characters and enemies are colored correctly
+                        byte smsColor = _vdp.CRAM[16 + colorIndex];
+                        int r = (smsColor & 0x03) * 85;
+                        int g = ((smsColor >> 2) & 0x03) * 85;
+                        int b = ((smsColor >> 4) & 0x03) * 85;
+
+                        // Background color (Index 0) is technically transparent for sprites, so we render it as magenta
+                        if (colorIndex == 0) { r = 255; g = 0; b = 255; }
+
+                        _pixelData[((tileY + y) * 256) + (tileX + x)] = (255 << 24) | (r << 16) | (g << 8) | b;
+                    }
+                }
+            }
+
+            // Blast the array into the Bitmap
+            var data = _vramBitmap.LockBits(new Rectangle(0, 0, 256, 128), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb);
+            Marshal.Copy(_pixelData, 0, data.Scan0, _pixelData.Length);
+            _vramBitmap.UnlockBits(data);
+
+            this.Invalidate();
+        }
+
+        protected override void OnPaint(PaintEventArgs e)
+        {
+            base.OnPaint(e);
+            // Draw it chunky and pixel-perfect
+            e.Graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.NearestNeighbor;
+            e.Graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.Half;
+            e.Graphics.DrawImage(_vramBitmap, new Rectangle(0, 0, this.ClientSize.Width, this.ClientSize.Height));
+        }
+
+        protected override void OnFormClosing(FormClosingEventArgs e)
+        {
+            _refreshTimer.Stop();
+            base.OnFormClosing(e);
+        }
+    }
+}