Refactor DrawCall to use VertexSpecification and update related rendering logic

Dashboard.Common/Drawing/DrawCall.cs

@@ -1,3 +1,4 @@
+using System.Collections.Immutable;
 using System.Diagnostics.CodeAnalysis;
 using System.Drawing;
 using System.Numerics;
@@ -176,11 +177,27 @@ namespace Dashboard.Drawing
         public int Divisor { get; init; } = 1;
     }
 
+    public record VertexSpecification(
+        ImmutableList<VertexAttribute> Attributes,
+        ImmutableList<IBuffer?> VertexBuffers
+    )
+    {
+        public IBuffer? ElementBuffer { get; init; } = null;
+    }
+
     public record struct UniformDescriptor(int Location, UniformType Type, long Offset, long Size);
 
-    public struct DrawCall(MeshPrimitive primitive, IBuffer vertexBuffer, int first, int count)
+    public struct DrawCall(MeshPrimitive primitive, VertexSpecification vertexSpec, int first, int count)
     {
         public IShader? ShaderPipeline { get; init; }
+        public VertexSpecification VertexSpecification { get; init; } = vertexSpec;
+
+        public MeshPrimitive Primitive { get; init; } = primitive;
+        public int First { get; init; } = first;
+        public int Count { get; init; } = count;
+        public int BaseVertex { get; init; } = 0;
+        public long Offset { get; init; } = 0;
+
         public Box2d ViewportRegion { get; init; } = new Box2d(Vector2.Zero, Vector2.PositiveInfinity);
         public Box2d ScissorRegion { get; init; } = new Box2d(Vector2.PositiveInfinity, Vector2.PositiveInfinity);
         public WindingOrder FrontFace { get; init; } = WindingOrder.Counterclockwise;
@@ -197,19 +214,11 @@ namespace Dashboard.Drawing
         public float PointSize { get; init; }= 1.0f;
         public float LineWidth { get; init; }= 1.0f;
 
-        public MeshPrimitive Primitive { get; init; } = primitive;
+
         public List<ITexture?> Textures { get; init; } = [];
-        public List<VertexAttribute> Attributes { get; init; } = [];
         public List<UniformDescriptor> Uniforms { get; init; } = [];
         public IndexType IndexType { get; init; } = IndexType.UnsignedShort;
 
-        public int First { get; init; } = first;
-        public int Count { get; init; } = count;
-        public long Offset { get; init; } = 0;
-        public int BaseVertex { get; init; } = 0;
-
-        public IBuffer VertexBuffer { get; init; } = vertexBuffer;
-        public IBuffer? ElementBuffer { get; init; }
         public ReadOnlyMemory<byte> UniformData { get; init; } = ReadOnlyMemory<byte>.Empty;
         public IBuffer? UniformBuffer { get; init; }
     }

Dashboard.OpenGL/Drawing/DirectRendering.cs

@@ -60,7 +60,7 @@ namespace Dashboard.OpenGL.Drawing
             Vector2 size = Context.FramebufferSize;
             drawCall.SetAll(size, _vao, false);
 
-            if (drawCall.ElementBuffer is null)
+            if (drawCall.VertexSpecification.ElementBuffer is null)
             {
                 GL.DrawArrays(drawCall.Primitive.OpenGL, drawCall.First, drawCall.Count);
             }

Dashboard.OpenGL/Drawing/GLStateExtensions.cs

@@ -336,15 +336,21 @@ namespace Dashboard.OpenGL.Drawing
             {
                 GL.BindVertexArray(vao);
 
-                if (call.ElementBuffer != null)
+                VertexSpecification spec = call.VertexSpecification;
+
+                if (spec.ElementBuffer != null)
                 {
-                    GL.BindBuffer(BufferTarget.ElementArrayBuffer, (call.ElementBuffer as GLBuffer)?.Handle ?? 0);
+                    GL.BindBuffer(BufferTarget.ElementArrayBuffer, (spec.ElementBuffer as GLBuffer)?.Handle ?? 0);
                 }
 
-                GL.BindBuffer(BufferTarget.ArrayBuffer, (call.VertexBuffer as GLBuffer)?.Handle ?? 0);
 
-                foreach(VertexAttribute attrib in call.Attributes)
+                for (int i = 0; i < spec.Attributes.Count; i++)
                 {
+                    VertexAttribute attrib = spec.Attributes[i];
+                    IBuffer? buffer = spec.VertexBuffers[i];
+
+                    GL.BindBuffer(BufferTarget.ArrayBuffer, (buffer as GLBuffer)?.Handle ?? 0);
+
                     GL.VertexAttribPointer(
                         (uint)attrib.Location,
                         attrib.Components,

tests/Dashboard.TestApplication/Program.cs

@@ -113,14 +113,17 @@ IShader shader = direct.CreatePipeline(new GlslShaderCreateInfo()
          """,
 });
 
-DrawCall call = new DrawCall(MeshPrimitive.Triangle, vertex, 0, 3)
-{
-    ShaderPipeline = shader,
-    Attributes =
+VertexSpecification spec = new VertexSpecification(
     [
         new VertexAttribute(0, 3, VertexAttributeType.Float, 0, 8 * sizeof(float)),
         new VertexAttribute(1, 4, VertexAttributeType.Float, 4 * sizeof(float), 8 * sizeof(float))
     ],
+    [vertex, vertex]
+);
+
+DrawCall call = new DrawCall(MeshPrimitive.Triangle, spec, 0, 3)
+{
+    ShaderPipeline = shader
 };
 
 window.EventRaised += (sender, eventArgs) =>