1 files changed, 144 insertions, 6 deletions

diff --git a/src/backend_mtl.m b/src/backend_mtl.m
index b3cd224..6ff5058 100644
--- a/src/backend_mtl.m
+++ b/src/backend_mtl.m
@@ -1,7 +1,6 @@
-#define GPU_METAL 1
+#include <celeritas.h>
 
 #ifdef GPU_METAL
-#include <celeritas.h>
 
 #define MTL_DEBUG_LAYER 1
 
@@ -16,6 +15,8 @@
 #define GLFW_EXPOSE_NATIVE_COCOA
 #import <GLFW/glfw3native.h>
 
+NAMESPACED_LOGGER(metal);
+
 // --- RAL types
 
 struct gpu_swapchain {
@@ -23,6 +24,22 @@ struct gpu_swapchain {
   CAMetalLayer* swapchain;
 };
 
+struct gpu_encoder {
+  id<MTLCommandBuffer> cmd_buffer;
+  id<MTLRenderCommandEncoder> cmd_encoder;
+};
+
+typedef struct metal_pipeline {
+  id<MTLRenderPipelineState> pso;
+} metal_pipeline;
+
+typedef struct metal_buffer {
+  id<MTLBuffer> id;
+} metal_buffer;
+
+TYPED_POOL(metal_buffer, buf);
+TYPED_POOL(metal_pipeline, pipeline);
+
 typedef struct metal_context {
   GLFWwindow* window;
   NSWindow* metal_window;
@@ -30,20 +47,25 @@ typedef struct metal_context {
   id<MTLDevice> device;
   id<CAMetalDrawable> surface;
   gpu_swapchain default_swapchain;
+  id<MTLLibrary> default_library;
 
   id<MTLCommandQueue> command_queue;
+
+  /* pools */
+  buf_pool bufpool;
+  pipeline_pool psopool; // pso = pipeline state object
 } metal_context;
 
 static metal_context ctx;
 
 void ral_backend_init(const char* window_name, struct GLFWwindow* window) {
-  printf("loading Metal backend\n");
+  TRACE("loading Metal backend");
 
-  printf("gpu device creation\n");
+  TRACE("gpu device creation");
   const id<MTLDevice> gpu = MTLCreateSystemDefaultDevice();
   ctx.device = gpu;
 
-  printf("window init\n");
+  TRACE("window init");
   glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
   glfwMakeContextCurrent(window);
   NSWindow* nswindow = glfwGetCocoaWindow(window);
@@ -55,14 +77,130 @@ void ral_backend_init(const char* window_name, struct GLFWwindow* window) {
   metal_layer.pixelFormat = MTLPixelFormatBGRA8Unorm;
   ctx.metal_window.contentView.layer = metal_layer;
   ctx.metal_window.contentView.wantsLayer = true;
+  ctx.default_swapchain.swapchain = metal_layer;
 
-  printf("command queue creation\n");
+  TRACE("command queue creation");
   const id<MTLCommandQueue> queue = [ctx.device newCommandQueue];
   ctx.command_queue = queue;
+
+  TRACE("resource pool init");
+  metal_buffer* buffer_storage = malloc(sizeof(metal_buffer) * 100);
+  ctx.bufpool = buf_pool_create(buffer_storage, 100, sizeof(metal_buffer));
+
+  metal_pipeline* pipeline_storage = malloc(sizeof(metal_pipeline) * 100);
+  ctx.psopool = pipeline_pool_create(pipeline_storage, 100, sizeof(metal_pipeline));
+
+  TRACE("create default metal lib");
+  NSError* nserr = 0x0;
+  id<MTLLibrary> default_library = [ctx.device newLibraryWithFile:@"build/shaders/default.metallib" error:&nserr];
+  if (!default_library) {
+    ERROR("Error loading metal lib\n");
+    exit(1);
+  }
+  ctx.default_library = default_library;
+
+  INFO("Successfully initialised Metal RAL backend");
 }
 
 void ral_backend_shutdown() {
   // no-op
 }
 
+buf_handle ral_buffer_create(u64 size, const void *data) {
+  buf_handle handle;
+  metal_buffer* buffer = buf_pool_alloc(&ctx.bufpool, &handle);
+  buffer->id = [ctx.device newBufferWithBytes:data length:size options:MTLResourceStorageModeShared];
+
+  return handle;
+}
+
+pipeline_handle ral_gfx_pipeline_create(gfx_pipeline_desc desc) {
+  TRACE("creating graphics pipeline");
+
+  pipeline_handle handle;
+  metal_pipeline* p = pipeline_pool_alloc(&ctx.psopool, &handle);
+
+  @autoreleasepool {
+    // setup vertex and fragment shaders
+    NSString* vertex_entry_point = [NSString stringWithUTF8String:desc.vertex.entry_point];
+    id<MTLFunction> vertex_func = [ctx.default_library newFunctionWithName:vertex_entry_point];
+    assert(vertex_func);
+
+    NSString* fragment_entry_point = [NSString stringWithUTF8String:desc.fragment.entry_point];
+    id<MTLFunction> fragment_func = [ctx.default_library newFunctionWithName:fragment_entry_point];
+    assert(fragment_func);
+
+    NSError* err = 0x0;
+    MTLRenderPipelineDescriptor* pld = [[MTLRenderPipelineDescriptor alloc] init];
+    // in auto release pool so dont need to call release()
+
+    [pld setLabel:@"Pipeline"];
+    [pld setVertexFunction:vertex_func];
+    [pld setFragmentFunction:fragment_func];
+    pld.colorAttachments[0].pixelFormat = MTLPixelFormatBGRA8Unorm;
+    pld.colorAttachments[0].blendingEnabled = YES;
+    assert(pld);
+
+    id<MTLRenderPipelineState> pso = [ctx.device newRenderPipelineStateWithDescriptor:pld error:&err];
+    assert(pso);
+    p->pso = pso;
+  }
+
+  return handle;
+}
+
+gpu_encoder* ral_render_encoder(render_pass_desc rpass_desc) {
+  id<MTLCommandBuffer> buffer = [ctx.command_queue commandBuffer];
+
+  // create renderpass descriptor
+  MTLRenderPassDescriptor* rpd = [[MTLRenderPassDescriptor alloc] init];
+  MTLRenderPassColorAttachmentDescriptor* cd = rpd.colorAttachments[0];
+  [cd setTexture:ctx.surface.texture];
+  [cd setLoadAction:MTLLoadActionClear];
+  MTLClearColor clearColor = MTLClearColorMake(41.0f/255.0f, 42.0f/255.0f, 48.0f/255.0f, 1.0);
+  [cd setClearColor:clearColor];
+  [cd setStoreAction:MTLStoreActionStore];
+
+  id<MTLRenderCommandEncoder> encoder = [buffer renderCommandEncoderWithDescriptor:rpd];
+
+  gpu_encoder* enc = malloc(sizeof(gpu_encoder));
+  enc->cmd_buffer = buffer;
+  enc->cmd_encoder = encoder;
+
+  return enc;
+}
+
+void ral_encoder_finish_and_submit(gpu_encoder* enc) {
+  [enc->cmd_encoder  endEncoding];
+  [enc->cmd_buffer presentDrawable:ctx.surface];
+  [enc->cmd_buffer commit];
+  [enc->cmd_buffer waitUntilCompleted];
+}
+
+void ral_encode_bind_pipeline(gpu_encoder *enc, pipeline_handle pipeline) {
+  metal_pipeline* p = pipeline_pool_get(&ctx.psopool, pipeline);
+  [enc->cmd_encoder setRenderPipelineState:p->pso];
+}
+
+void ral_encode_set_vertex_buf(gpu_encoder *enc, buf_handle vbuf) {
+  metal_buffer* b = buf_pool_get(&ctx.bufpool, vbuf);
+  [enc->cmd_encoder setVertexBuffer:b->id offset:0 atIndex:0 ];
+}
+
+void ral_encode_draw_tris(gpu_encoder* enc, size_t start, size_t count) {
+  MTLPrimitiveType tri_primitive = MTLPrimitiveTypeTriangle;
+  [enc->cmd_encoder drawPrimitives:tri_primitive vertexStart:start vertexCount:count];
+}
+
+void ral_frame_start() {}
+
+void ral_frame_draw(scoped_draw_commands draw_fn) {
+  @autoreleasepool {
+    ctx.surface = [ctx.default_swapchain.swapchain nextDrawable];
+    draw_fn();
+  }
+}
+
+void ral_frame_end() {}
+
 #endif
\ No newline at end of file