implement pipeline cache

include/renderer_mtl/mtl_pipeline_cache.hpp

@@ -0,0 +1,83 @@
+#pragma once
+
+#include "pica_to_mtl.hpp"
+
+using namespace PICA;
+
+namespace Metal {
+
+struct PipelineHash {
+    ColorFmt colorFmt;
+    DepthFmt depthFmt;
+};
+
+// Bind the vertex buffer to binding 30 so that it doesn't occupy the lower indices
+#define VERTEX_BUFFER_BINDING_INDEX 30
+
+// This pipeline only caches the pipeline with all of its color and depth attachment variations
+class PipelineCache {
+public:
+    PipelineCache() = default;
+
+    ~PipelineCache() {
+        clear();
+        vertexDescriptor->release();
+        vertexFunction->release();
+        fragmentFunction->release();
+    }
+
+    void set(MTL::Device* dev, MTL::Function* vert, MTL::Function* frag, MTL::VertexDescriptor* vertDesc) {
+        device = dev;
+        vertexFunction = vert;
+        fragmentFunction = frag;
+        vertexDescriptor = vertDesc;
+    }
+
+    MTL::RenderPipelineState* get(PipelineHash hash) {
+        u8 intHash = (u8)hash.colorFmt << 4 | (u8)hash.depthFmt;
+        auto& pipeline = pipelineCache[intHash];
+        if (!pipeline) {
+            MTL::RenderPipelineDescriptor* desc = MTL::RenderPipelineDescriptor::alloc()->init();
+            desc->setVertexFunction(vertexFunction);
+            desc->setFragmentFunction(fragmentFunction);
+            desc->setVertexDescriptor(vertexDescriptor);
+
+            auto colorAttachment = desc->colorAttachments()->object(0);
+            colorAttachment->setPixelFormat(toMTLPixelFormatColor(hash.colorFmt));
+            colorAttachment->setBlendingEnabled(true);
+           	colorAttachment->setSourceRGBBlendFactor(MTL::BlendFactorSourceAlpha);
+           	colorAttachment->setDestinationRGBBlendFactor(MTL::BlendFactorOneMinusSourceAlpha);
+           	colorAttachment->setSourceAlphaBlendFactor(MTL::BlendFactorSourceAlpha);
+           	colorAttachment->setDestinationAlphaBlendFactor(MTL::BlendFactorOneMinusSourceAlpha);
+
+            desc->setDepthAttachmentPixelFormat(toMTLPixelFormatDepth(hash.depthFmt));
+
+           	NS::Error* error = nullptr;
+           	pipeline = device->newRenderPipelineState(desc, &error);
+           	if (error) {
+          		Helpers::panic("Error creating draw pipeline state: %s", error->description()->cString(NS::ASCIIStringEncoding));
+           	}
+
+            desc->release();
+        }
+
+        return pipeline;
+    }
+
+    void clear() {
+        for (auto& pair : pipelineCache) {
+            pair.second->release();
+        }
+        pipelineCache.clear();
+    }
+
+private:
+    std::unordered_map<u8, MTL::RenderPipelineState*> pipelineCache;
+
+    MTL::Device* device;
+    MTL::Function* vertexFunction;
+    MTL::Function* fragmentFunction;
+    MTL::VertexDescriptor* vertexDescriptor;
+};
+
+} // namespace Metal