implement core branching logic for metal enumeration of physical devices

Gryphn/GryphnLoader/src/device/gryphn_physical_device.c

@@ -0,0 +1,7 @@
+#include "gryphn_physical_device.h"
+#include "instance/gryphn_instance.h"
+#include "stdint.h"
+
+gnReturnCode gnEnumeratePhysicalDevices(gnInstance instance, uint32_t* deviceCount, gnPhysicalDevice* devices) {
+    return instance->dispatchTable.enumeratePhysicalDevices(instance, deviceCount, devices);
+}

Gryphn/GryphnLoader/src/device/gryphn_physical_device.h

@@ -0,0 +1,6 @@
+#pragma once
+#include "gryphn_handle.h"
+#include "gryphn_return_code.h"
+#include "stdint.h"
+
+gnReturnCode gnEnumeratePhysicalDevices(gnInstance instance, uint32_t* deviceCount, gnPhysicalDevice* devices);

Gryphn/GryphnLoader/src/gryphn_handle.h

@@ -1,4 +1,7 @@
 #pragma once
 
 #define GN_HANDLE(type) typedef struct type##_t* type
+#define GN_IMPLEMENTATION_HANDLE(type) typedef void* type
+
 GN_HANDLE(gnInstance);
+GN_IMPLEMENTATION_HANDLE(gnPhysicalDevice);

Gryphn/GryphnLoader/src/instance/dispatch/gryphn_instance_dispatch_table.h

@@ -2,7 +2,10 @@
 #include "gryphn_handle.h"
 
 typedef gnReturnCode (*PFN_gnDestroyInstance)(gnInstance);
+typedef gnReturnCode (*PFN_enumeratePhysicalDevices)(gnInstance, uint32_t*, gnPhysicalDevice*);
+
 
 typedef struct gnInstanceDispatchTable {
     PFN_gnDestroyInstance destroyInstance;
+    PFN_enumeratePhysicalDevices enumeratePhysicalDevices;
 } gnInstanceDispatchTable;

Gryphn/apis/GryphnMetal/src/metal.m

@@ -2,6 +2,7 @@
 #include "stdio.h"
 #include "instance/gryphn_instance.h"
 #include "gryphn_handle.h"
+#include "metal_functions.h"
 
 extern "C" uint32_t gnInternalIsApiSupported(gnVersion version) {
         if (version != gnCreateVersion(1, 0, 0)) return 0;
@@ -13,12 +14,11 @@ extern "C" uint32_t gnInternalIsApiSupported(gnVersion version) {
 }
 
 gnReturnCode destroyBackend(gnInstance instance) {
-    printf("Calling destroy instance");
     return GN_SUCCESS;
 }
 
 extern "C" gnReturnCode initBackend(gnInstance instance, gnInstanceCreateInfo* info) {
-    printf("calling init instance\n");
     instance->dispatchTable.destroyInstance = destroyBackend;
+    instance->dispatchTable.enumeratePhysicalDevices = metalEnumeratePhysicalDevices;
     return GN_SUCCESS;
 }

Gryphn/apis/GryphnMetal/src/metal_device.m

@@ -0,0 +1,9 @@
+#include "metal_functions.h"
+#include "stdio.h"
+#include "stdint.h"
+
+gnReturnCode metalEnumeratePhysicalDevices(gnInstance instance, uint32_t* deviceCount, gnPhysicalDevice* devices) {
+    *deviceCount = 0;
+    return GN_SUCCESS;
+}
+c

Gryphn/apis/GryphnMetal/src/metal_functions.h

@@ -0,0 +1,7 @@
+#pragma once
+#include "gryphn_handle.h"
+#include "gryphn_return_code.h"
+#include "stdint.h"
+
+
+gnReturnCode metalEnumeratePhysicalDevices(gnInstance instance, uint32_t* deviceCount, gnPhysicalDevice* devices);

Gryphn/gryphn.h

@@ -4,6 +4,7 @@
 extern "C" {
 #endif
 #include "GryphnLoader/src/instance/gryphn_instance.h"
+#include "GryphnLoader/src/device/gryphn_physical_device.h"
 #ifdef __cplusplus
 }
 #endif

main.cpp

@@ -40,9 +40,19 @@ void createInstance() {
     free(backends);
 }
 
+void createDevice() {
+    uint32_t physicalDeviceCount;
+    CHECK(gnEnumeratePhysicalDevices(instance, &physicalDeviceCount, nullptr));
+    gnPhysicalDevice* devices = (gnPhysicalDevice*)malloc(sizeof(gnPhysicalDevice) * physicalDeviceCount);
+    CHECK(gnEnumeratePhysicalDevices(instance, &physicalDeviceCount, devices));
+
+    std::cout << "Found " << physicalDeviceCount << " physical devices:\n";
+}
+
 int main() {
     try {
         createInstance();
+        createDevice();
     } catch (const std::exception& e) {
         std::cerr << "Caught Exception: " << e.what() << "\n";
         return 0;