General progress on getting OpenGL based rendering.

2020-06-01 01:27:38 -05:00
parent 5e85eb5de1
commit e59e78e08c
40 changed files with 995 additions and 501 deletions
--- a/src/SlatedGameToolkit.Framework/Graphics/Render/Batch.cs
+++ b/src/SlatedGameToolkit.Framework/Graphics/Render/Batch.cs
@@ -0,0 +1,99 @@
+using System;
+using System.Drawing;
+using System.Numerics;
+using SlatedGameToolkit.Framework.Graphics.Meshes;
+using SlatedGameToolkit.Framework.Graphics;
+using SlatedGameToolkit.Framework.Graphics.Textures;
+using SlatedGameToolkit.Framework.Graphics.Shaders;
+
+namespace SlatedGameToolkit.Framework.Graphics.Render
+{
+    public class Batch : IDisposable {
+        private Texture texture;
+        private bool disposed;
+        private VertexArray vertexArray;
+        private const int VERTEX_LENGTH = 6;
+        private GLMultiDrawElements multiDrawElements;
+        public bool Batching { get; private set; }
+        private float[] data;
+        private uint[] indices;
+        private uint[] lengths;
+        private uint[] offsets;
+        private uint dataIndex, indicesIndex, lengthsIndex;
+
+        public Batch(uint BatchVertexSize = 4096) {
+            multiDrawElements = GLFunctionUtils.RetrieveGLDelegate<GLMultiDrawElements>("glMultDrawElements");
+            indices = new uint[BatchVertexSize];
+            lengths = new uint[BatchVertexSize];
+            offsets = new uint[BatchVertexSize];
+            data = new float[BatchVertexSize * VERTEX_LENGTH];
+
+            vertexArray = new VertexArray();
+
+            VertexAttributeDefinition[] definitions = new VertexAttributeDefinition[3];
+            definitions[0] = new VertexAttributeDefinition(0, 3, 3 * sizeof(float), 0);
+            definitions[1] = new VertexAttributeDefinition(1, 4, 1 * sizeof(float), 3 * sizeof(float));
+            definitions[2] = new VertexAttributeDefinition(2, 2, 2 * sizeof(float), 4 * sizeof(float));
+            vertexArray.defineVertexAttributes(definitions: definitions);
+        }
+
+        public virtual void Begin(Texture texture) {
+            if (Batching) throw new InvalidOperationException("This batch is already started.");
+            this.texture = texture ?? throw new ArgumentNullException("texture");
+            this.Batching = true;
+        }
+
+        public virtual void Dispose()
+        {
+            if (disposed) return;
+            disposed = true;
+            vertexArray.Dispose();
+        }
+
+        public virtual void Draw(IMeshable meshable, Color color) {
+            ValueTuple<Vector3, Vector2>[] vertices = meshable.Vertices;
+            uint[] indices = meshable.Elements;
+            if (vertices.Length * VERTEX_LENGTH + dataIndex >= data.Length || indices.Length + indicesIndex >= indicesIndex) Flush();
+            for (int i = 0; i < vertices.Length; i++) {
+                data[dataIndex] = vertices[i].Item1.X;
+                dataIndex++;
+                data[dataIndex] = vertices[i].Item1.Y;
+                dataIndex++;
+                data[dataIndex] = vertices[i].Item1.Z;
+                dataIndex++;
+
+                data[dataIndex] = color.ToArgb();
+                dataIndex++;
+
+                data[dataIndex] = vertices[i].Item2.X;
+                dataIndex++;
+                data[dataIndex] = vertices[i].Item2.Y;
+                dataIndex++;
+
+                uint elementsCount = (uint)indices.Length;
+                Array.Copy(indices, indices, elementsCount);
+                indicesIndex += elementsCount;
+
+                lengths[lengthsIndex] = elementsCount;
+                lengthsIndex ++;
+            }
+        }
+
+        public virtual void End() {
+            if (!Batching) throw new InvalidOperationException("This batch was never started.");
+            this.Batching = false;
+            Flush();
+        }
+
+        protected virtual void Flush() {
+            texture.Use();
+            vertexArray.Use();
+            vertexArray.BufferVertices(data);
+            vertexArray.BufferIndices(indices);
+            dataIndex = 0;
+            indicesIndex = 0;
+            lengthsIndex = 0;
+            multiDrawElements(GLEnums.GL_TRIANGLE_STRIP, lengths, GLEnums.GL_UNSIGNED_INT, offsets);
+        }
+    }
+}