A GTK GLArea widget that renders pyramidal slide tiles directly on the GPU. Eliminates ReadPixels overhead by rendering to screen instead of copying to CPU. Supports SkiaSharp overlay for annotations via GRContext. More...

Inheritance diagram for BioGTK.SlideGLArea:

Public Member Functions
void	UploadTileTexture (TileIndex index, byte[] pixelData, int tileWidth, int tileHeight)
	Upload a tile texture to the GPU. Call from the main thread.

bool	HasTileTexture (TileIndex index)
	Check if a tile texture is already in the GPU cache.

void	ReleaseTileTexture (TileIndex index)
	Release a specific tile texture.

void	ReleaseLevelTextures (int level)
	Release all textures for a specific pyramid level.

void	ClearTextureCache ()
	Clear all cached textures.

void	RequestRedraw ()
	Request a redraw of the GLArea.

void	SetTilesToRender (IEnumerable< TileRenderInfo > tiles)
	Prepare tiles for rendering. Call before RequestRedraw().

byte[]	ReadPixels ()
	Read pixels from the current framebuffer (for export/save operations). This is slow - only use for export, not display.

Properties
List< TileRenderInfo >	TilesToRender = new() `[get]`

bool	NeedsRedraw = true `[get, set]`

Events
Action< SKCanvas, int, int >	OnSkiaRender
	Event fired during Skia rendering phase for annotation drawing.

Detailed Description

A GTK GLArea widget that renders pyramidal slide tiles directly on the GPU. Eliminates ReadPixels overhead by rendering to screen instead of copying to CPU. Supports SkiaSharp overlay for annotations via GRContext.

Definition at line 19 of file SlideGLArea.cs.

Constructor & Destructor Documentation

◆ SlideGLArea()

BioGTK.SlideGLArea.SlideGLArea ( )

Definition at line 115 of file SlideGLArea.cs.

        {
            HasDepthBuffer = false;
            HasStencilBuffer = false;
            AutoRender = false;  // We control when to render
 
            Realized += OnRealized;
            //Unrealize += OnUnrealize;
            Render += OnRender;
            Resize += OnResized;
        }

Member Function Documentation

◆ ClearTextureCache()

void BioGTK.SlideGLArea.ClearTextureCache ( )

Clear all cached textures.

Definition at line 481 of file SlideGLArea.cs.

        {
            if (!_glInitialized) return;
 
            MakeCurrent();
 
            foreach (var tex in _textureCache.Values)
            {
                GL.DeleteTexture(tex);
            }
            _textureCache.Clear();
        }

◆ HasTileTexture()

bool BioGTK.SlideGLArea.HasTileTexture ( TileIndex index )

Check if a tile texture is already in the GPU cache.

Definition at line 443 of file SlideGLArea.cs.

        {
            return _textureCache.ContainsKey(index);
        }

◆ ReadPixels()

byte[] BioGTK.SlideGLArea.ReadPixels ( )

Read pixels from the current framebuffer (for export/save operations). This is slow - only use for export, not display.

Definition at line 532 of file SlideGLArea.cs.

        {
            if (!_glInitialized) return null;
 
            MakeCurrent();
 
            int width = AllocatedWidth;
            int height = AllocatedHeight;
 
            byte[] pixels = new byte[width * height * 4];
            GL.ReadPixels(0, 0, width, height, PixelFormat.Rgba, PixelType.UnsignedByte, pixels);
 
            return pixels;
        }

◆ ReleaseLevelTextures()

void BioGTK.SlideGLArea.ReleaseLevelTextures ( int level )

Release all textures for a specific pyramid level.

Definition at line 464 of file SlideGLArea.cs.

        {
            if (!_glInitialized) return;
 
            MakeCurrent();
 
            var toRemove = _textureCache.Where(kvp => kvp.Key.Level == level).ToList();
            foreach (var kvp in toRemove)
            {
                GL.DeleteTexture(kvp.Value);
                _textureCache.Remove(kvp.Key);
            }
        }

◆ ReleaseTileTexture()

void BioGTK.SlideGLArea.ReleaseTileTexture ( TileIndex index )

Release a specific tile texture.

Definition at line 451 of file SlideGLArea.cs.

        {
            if (_textureCache.TryGetValue(index, out int tex))
            {
                MakeCurrent();
                GL.DeleteTexture(tex);
                _textureCache.Remove(index);
            }
        }

◆ RequestRedraw()

void BioGTK.SlideGLArea.RequestRedraw ( )

Request a redraw of the GLArea.

Definition at line 512 of file SlideGLArea.cs.

        {
            NeedsRedraw = true;
            QueueRender();
        }

◆ SetTilesToRender()

void BioGTK.SlideGLArea.SetTilesToRender ( IEnumerable< TileRenderInfo > tiles )

Prepare tiles for rendering. Call before RequestRedraw().

Definition at line 521 of file SlideGLArea.cs.

        {
            TilesToRender.Clear();
            TilesToRender.AddRange(tiles);
            Console.WriteLine($"Set {TilesToRender.Count} tiles to render");
        }

◆ UploadTileTexture()

void BioGTK.SlideGLArea.UploadTileTexture	(	TileIndex	index,
		byte[]	pixelData,
		int	tileWidth,
		int	tileHeight )

Upload a tile texture to the GPU. Call from the main thread.

Definition at line 390 of file SlideGLArea.cs.

        {
            if (!_glInitialized)
            {
                Console.WriteLine("WARNING: GL not initialized, cannot upload texture");
                return;
            }
 
            if (pixelData == null || pixelData.Length == 0)
            {
                Console.WriteLine($"WARNING: Empty pixel data for tile {index}");
                return;
            }
 
            MakeCurrent();
 
            // Check if already cached
            if (_textureCache.ContainsKey(index))
            {
                Console.WriteLine($"Tile {index} already cached");
                return;
            }
 
            // Evict old textures if cache is full
            if (_textureCache.Count >= MAX_CACHED_TEXTURES)
            {
                EvictOldestTextures(MAX_CACHED_TEXTURES / 4);
            }
 
            // Create and upload texture
            int tex = GL.GenTexture();
            GL.BindTexture(TextureTarget.Texture2D, tex);
 
            GL.PixelStore(PixelStoreParameter.UnpackAlignment, 1);
 
            // CRITICAL FIX: Use Rgba instead of Bgra for internal format consistency
            GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba,
                          tileWidth, tileHeight, 0, PixelFormat.Rgba, PixelType.UnsignedByte, pixelData);
 
            GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Linear);
            GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear);
            GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapS, (int)TextureWrapMode.ClampToEdge);
            GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapT, (int)TextureWrapMode.ClampToEdge);
 
            GL.BindTexture(TextureTarget.Texture2D, 0);
 
            _textureCache[index] = tex;
            Console.WriteLine($"Uploaded tile {index} as texture {tex} ({tileWidth}x{tileHeight}, {pixelData.Length} bytes)");
        }

Property Documentation

◆ NeedsRedraw

bool BioGTK.SlideGLArea.NeedsRedraw = true

getset

Definition at line 56 of file SlideGLArea.cs.

56{ get; set; } = true;

◆ TilesToRender

List<TileRenderInfo> BioGTK.SlideGLArea.TilesToRender = new()

get

Definition at line 55 of file SlideGLArea.cs.

55{ get; } = new();

Event Documentation

◆ OnSkiaRender

Action<SKCanvas, int, int> BioGTK.SlideGLArea.OnSkiaRender

Event fired during Skia rendering phase for annotation drawing.

Definition at line 61 of file SlideGLArea.cs.

The documentation for this class was generated from the following file:

BioGTK/BioGTK/Source/SlideGLArea.cs

Public Member Functions

Properties

Events