From f425dfc20bc3e5af7d7bc83a4a48b80a240dd4e6 Mon Sep 17 00:00:00 2001
From: Greg Wells <gregory@Gregs-MacBook-Pro.local>
Date: Fri, 6 Jun 2025 17:08:24 -0400
Subject: [PATCH] metal buffer API

---
 .../metal/src/core/buffer/metal_buffer.h      |  7 ++++
 .../metal/src/core/buffer/metal_buffer.m      | 41 +++++++++++++++++++
 2 files changed, 48 insertions(+)
 create mode 100644 rendering_api/metal/src/core/buffer/metal_buffer.h
 create mode 100644 rendering_api/metal/src/core/buffer/metal_buffer.m

diff --git a/rendering_api/metal/src/core/buffer/metal_buffer.h b/rendering_api/metal/src/core/buffer/metal_buffer.h
new file mode 100644
index 0000000..a90953b
--- /dev/null
+++ b/rendering_api/metal/src/core/buffer/metal_buffer.h
@@ -0,0 +1,7 @@
+#pragma once
+#import <Metal/Metal.h>
+
+struct gnPlatformBuffer_t {
+    id<MTLBuffer> buffer, stagingBuffer;
+    bool useStagingBuffer;
+};
diff --git a/rendering_api/metal/src/core/buffer/metal_buffer.m b/rendering_api/metal/src/core/buffer/metal_buffer.m
new file mode 100644
index 0000000..5feae57
--- /dev/null
+++ b/rendering_api/metal/src/core/buffer/metal_buffer.m
@@ -0,0 +1,41 @@
+#include "metal_buffer.h"
+#include "core/buffers/gryphn_buffer.h"
+#include "core/output_device/gryphn_output_device.h"
+#include "core/devices/metal_output_devices.h"
+
+gnReturnCode gnCreateBufferFn(gnBufferHandle buffer, gnOutputDeviceHandle device, gnBufferInfo info) {
+    buffer->buffer = malloc(sizeof(struct gnPlatformBuffer_t));
+    MTLResourceOptions option;
+    buffer->buffer->useStagingBuffer = (info.usage == GN_DYNAMIC_DRAW) ? NO : YES;
+    if (info.usage == GN_DYNAMIC_DRAW)
+        option = MTLResourceStorageModeShared;
+    else {
+        option = MTLResourceStorageModePrivate;
+        buffer->buffer->stagingBuffer = [device->outputDevice->device newBufferWithLength:info.size options:MTLResourceStorageModeShared];
+    }
+    buffer->buffer->buffer = [device->outputDevice->device newBufferWithLength:info.size options:option];
+    return GN_SUCCESS;
+}
+void gnBufferDataFn(gnBufferHandle buffer, size_t dataSize, void* data) {
+    void* bufferData;
+    if (buffer->buffer->useStagingBuffer) {
+        memcpy(buffer->buffer->stagingBuffer.contents, data, dataSize);
+        id<MTLCommandBuffer> commandBuffer = [buffer->device->outputDevice->transferQueue commandBuffer];
+        id<MTLBlitCommandEncoder> encoder = [commandBuffer blitCommandEncoder];
+        [encoder copyFromBuffer:buffer->buffer->stagingBuffer sourceOffset:0 toBuffer:buffer->buffer->buffer destinationOffset:0 size:dataSize];
+        [encoder endEncoding];
+        [commandBuffer commit];
+        [commandBuffer waitUntilCompleted];
+    } else
+        memcpy(buffer->buffer->buffer.contents, data, dataSize);
+}
+void gnDestroyBufferFn(gnBufferHandle buffer) {
+    // if (buffer->buffer->useStagingBuffer == gnTrue) {
+    //     vkDestroyBuffer(buffer->device->outputDevice->device, buffer->buffer->stagingBuffer, NULL);
+    //     vkFreeMemory(buffer->device->outputDevice->device, buffer->buffer->stagingBufferMemory, NULL);
+    // }
+
+    // vkDestroyBuffer(buffer->device->outputDevice->device, buffer->buffer->buffer, NULL);
+    // vkFreeMemory(buffer->device->outputDevice->device, buffer->buffer->bufferMemory, NULL);
+    // free(buffer->buffer);
+}