Metal setup merge (#1616)

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: Alex Cristici <alex.cristici@gmail.com>
Co-authored-by: mwilsnd <mwilsnd@gmail.com>
Co-authored-by: Stefan Karschti <stefan.karschti@gmail.com>
Co-authored-by: Bart Louwers <bart@emeel.net>
Co-authored-by: Alex Cristici <alex@skoon.energy>
Co-authored-by: Bart Louwers <bart.louwers@gmail.com>
Co-authored-by: Wei Chen <alanchenboy@gmail.com>
Co-authored-by: Siarhei Fedartsou <siarhei.fedartsou@gmail.com>
Co-authored-by: tdcosta100 <tdcosta100@gmail.com>

src/mbgl/mtl/buffer_resource.cpp

@@ -0,0 +1,44 @@
+#include <mbgl/mtl/buffer_resource.hpp>
+
+#include <Metal/MTLDevice.hpp>
+
+namespace mbgl {
+namespace mtl {
+
+BufferResource::BufferResource(MTLDevicePtr device_, const void* data, std::size_t size, MTL::ResourceOptions usage_)
+    : device(std::move(device_)),
+      usage(usage_) {
+    if (data && size) {
+        buffer = NS::TransferPtr(device->newBuffer(data, static_cast<NS::UInteger>(size), usage));
+    } else {
+        buffer = NS::TransferPtr(device->newBuffer(static_cast<NS::UInteger>(size), usage));
+    }
+}
+
+BufferResource::BufferResource(const BufferResource& other)
+    : device(other.device),
+      usage(other.usage) {
+    if (other.buffer) {
+        buffer = NS::TransferPtr(device->newBuffer(other.buffer->contents(), other.buffer->length(), other.usage));
+    }
+}
+
+BufferResource::BufferResource(BufferResource&& other)
+    : device(std::move(other.device)),
+      buffer(std::move(other.buffer)),
+      usage(other.usage) {}
+
+void BufferResource::update(const void* data, std::size_t size, std::size_t offset) {
+    assert(buffer && (data || size == 0));
+    if (buffer && data && size > 0) {
+        assert(buffer->contents());
+        if (void* content = buffer->contents()) {
+            const auto size_ = std::min(size, static_cast<std::size_t>(buffer->length()) - offset);
+            assert(size == size_);
+            std::memcpy(static_cast<uint8_t*>(content) + offset, data, size_);
+        }
+    }
+}
+
+} // namespace mtl
+} // namespace mbgl