feat(renderer): Virtual resource registry first version

src/renderer/init.c

@@ -1,9 +1,12 @@
 #include "renderer.h"
 #include "backend_api.h" 
+#include "runtime/runtime.h"
 
+#include <SDL2/SDL_syswm.h>
 #include <runtime/config.h>
 
 RT_CVAR_S(rt_Renderer, "The used renderer. Available options: vk, dx11. (Default: vk)", "vk");
+extern rt_cvar r_MaxRenderResources;
 
 RT_DLLEXPORT void rtRegisterRenderCVARs(void) {
     rtRegisterCVAR(&rt_Renderer);
@@ -13,10 +16,23 @@ RT_DLLEXPORT void rtRegisterRenderBackendCVARs(void) {
     g_render_backend.RegisterCVARs();    
 }
 
+rt_render_device_i g_device_i;
+
+extern rt_result InitVirtualResourceRegistry(void);
+extern void ShutdownVirtualResourceRegistry(void);
 
 RT_DLLEXPORT rt_result rtInitRenderer(const rt_renderer_window_info *info) {
     rt_render_backend_init_result backend_res = g_render_backend.Init(info);
-    return backend_res.result;
+    if (backend_res.result != RT_SUCCESS)
+        return backend_res.result;
+    g_device_i = backend_res.device;
+    
+    rt_result res;
+    if ((res = InitVirtualResourceRegistry()) != RT_SUCCESS) {
+        g_render_backend.Shutdown();
+        return res;
+    }
+    return res;
 }
 
 RT_DLLEXPORT void rtShutdownRenderer(void) {

src/renderer/meson.build

@@ -19,11 +19,14 @@ renderer_lib = library('renderer',
     'backend_api.h',
     'renderer.h',
     'render_mesh.h',
+    'render_resource.h',
+    'virtual_resource_registry.h',
 
     'init.c',
     'load_stub.c',
     'meshlet_pools.c',
     'render_mesh.c',
+    'virtual_resource_registry.c',
 	dependencies: [m_dep, thread_dep],
 	link_with: renderer_link_libs,
 	include_directories: engine_incdir,

src/renderer/render_resource.h

@@ -0,0 +1,97 @@
+#ifndef RT_RENDERER_RENDER_RESOURCE_H
+#define RT_RENDERER_RENDER_RESOURCE_H
+
+#include <stdint.h>
+#include <runtime/runtime.h>
+#include <runtime/resources.h>
+
+typedef enum {
+    RT_RENDER_RESOURCE_TYPE_INVALID,
+    RT_RENDER_RESOURCE_TYPE_BUFFER,
+    RT_RENDER_RESOURCE_TYPE_TEXTURE2D,
+    /* Max is 2**6 = 64 */
+} rt_render_resource_type;
+
+/* Handle to a render resource. 
+ * The layout is:
+ * | type : 6 | version : 6 | index : 20 |
+ * MSB                                 LSB
+ */
+typedef struct {
+    uint32_t value;
+} rt_render_resource_handle;
+
+#define RT_RENDER_RESOURCE_MAX_VERSION 0x3f
+
+/* Extract the type part of a render resource handle */
+static RT_INLINE rt_render_resource_type rtGetRenderResourceHandleType(rt_render_resource_handle h) {
+    return (rt_render_resource_type)((h.value >> 26) & 0x3f);    
+}
+
+/* Extract the version part of a render resource handle */
+static RT_INLINE uint32_t rtGetRenderResourceHandleVersion(rt_render_resource_handle h) {
+    return (h.value >> 20) & 0x3f;
+}
+
+/* Extract the index part of a render resource handle */
+static RT_INLINE uint32_t rtGetRenderResourceHandleIndex(rt_render_resource_handle h) {
+    return h.value & 0xfffff;
+}
+
+/* Create a render resource handle. This only does the required bit-shifting, it does not actually register any resource for the handle. */
+static RT_INLINE rt_render_resource_handle rtMakeRenderResourceHandle(rt_render_resource_type type, uint32_t version, uint32_t index) {
+    rt_render_resource_handle h;
+    h.value = ((type & 0x3f) << 26u) | ((version & 0x3f) << 20u) | (index & 0xfffff);
+    return h;
+}
+
+/* Resource description structs */
+
+typedef enum {
+    RT_RENDER_BUFFER_USAGE_NONE           = 0,
+    RT_RENDER_BUFFER_USAGE_VERTEX_BUFFER  = 0x01,
+    RT_RENDER_BUFFER_USAGE_INDEX_BUFFER   = 0x02,
+    RT_RENDER_BUFFER_USAGE_STORAGE_BUFFER = 0x04,
+
+    /* The buffer will be used as a source to populate other resources
+     * with data */
+    RT_RENDER_BUFFER_USAGE_UPLOAD_BUFFER  = 0x10,
+} rt_render_buffer_usage_flags;
+
+typedef enum {
+    /* The buffer can reside in memory that can only be accessed by the GPU */
+    RT_RENDER_BUFFER_ACCESS_GPU_ONLY    = 0x01,
+
+    /* The buffer needs to be in CPU accessible memory */
+    RT_RENDER_BUFFER_ACCESS_CPU_AND_GPU = 0x02,
+
+    /* The buffer is short-lived (will be destroyed at the end of the frame) */
+    RT_RENDER_BUFFER_ACCESS_TRANSIENT   = 0x04,
+} rt_render_buffer_access_flags;
+
+/* Describes a gpu buffer */
+typedef struct {
+    /* The required size in bytes */
+    size_t size;
+
+    /* Bitmask describing the usage of the buffer */
+    rt_render_buffer_usage_flags usage;
+
+    /* Bitmask describing the access the buffer needs to support */
+    rt_render_buffer_access_flags access;
+
+    /* ResourceID of the resource that will be used to populate this buffer. */
+    rt_resource_id source_resource;
+} rt_render_buffer_desc;
+
+/* Describes a gpu texture */
+typedef struct {
+    /* Width in pixels */
+    uint32_t width;
+
+    /* Height in pixels */
+    uint32_t height;
+} rt_render_texture2d_desc;
+
+#endif
+

src/renderer/renderer.h

@@ -42,7 +42,6 @@ RT_DLLEXPORT rt_result rtLoadRenderBackend(void);
 
 RT_DLLEXPORT void rtRegisterRenderBackendCVARs(void);
 
-
 RT_DLLEXPORT rt_result rtInitRenderer(const rt_renderer_window_info *window);
 
 RT_DLLEXPORT void rtShutdownRenderer(void);

src/renderer/virtual_resource_registry.c

@@ -0,0 +1,138 @@
+#include <runtime/config.h>
+#include <runtime/threading.h>
+#include <runtime/runtime.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+#include "virtual_resource_registry.h"
+#include "render_resource.h"
+
+RT_CVAR_SZ(r_MaxRenderResources, "Maximum number of render resources that can exist simultaneously. (Default: 16384)", 16384);
+
+typedef struct {
+    rt_render_resource_handle *handles;
+    struct {
+        union {
+            /* For management */
+            uint32_t next_free;
+            
+            rt_render_buffer_desc buffer;
+            rt_render_texture2d_desc texture2d;
+        };
+    } *descs;
+    uint32_t first_free;
+    rt_rwlock lock;
+} rt_description_table;
+
+static rt_description_table _description_tab;
+
+rt_result InitVirtualResourceRegistry(void) {
+    _description_tab.handles = calloc(r_MaxRenderResources.sz, sizeof(rt_render_resource_handle));
+    if (!_description_tab.handles)
+        return RT_OUT_OF_MEMORY;
+    _description_tab.descs = calloc(r_MaxRenderResources.sz, sizeof(*_description_tab.descs));
+    if (!_description_tab.descs) {
+        free(_description_tab.handles);
+        return RT_OUT_OF_MEMORY;
+    }
+    rt_create_rwlock_result lock_res = rtCreateRWLock();
+    if (!lock_res.ok) {
+        free(_description_tab.handles);
+        free(_description_tab.descs);
+        return RT_UNKNOWN_ERROR;
+    }
+    _description_tab.lock = lock_res.lock;
+    _description_tab.first_free = 0;
+    for (uint32_t i = 0; i < r_MaxRenderResources.sz; ++i) {
+        _description_tab.descs[i].next_free = i + 1;
+    }
+    return RT_SUCCESS;
+}
+
+void ShutdownVirtualResourceRegistry(void) {
+    free(_description_tab.handles);
+    free(_description_tab.descs);
+    rtDestroyRWLock(&_description_tab.lock);
+}
+
+/* Returns true if the handle refers to an existing resource. */
+bool rtIsRenderResourceKnown(rt_render_resource_handle h) {
+    uint32_t idx = rtGetRenderResourceHandleIndex(h);
+    if (idx >= r_MaxRenderResources.sz)
+        return false;
+    rtLockRead(&_description_tab.lock);
+    bool is_known = _description_tab.handles[idx].value == h.value;
+    rtUnlockRead(&_description_tab.lock);
+    return is_known;
+}
+
+static const void *GetResourceDescription(rt_render_resource_handle h) {
+    rt_render_resource_type type = rtGetRenderResourceHandleType(h);    
+    uint32_t idx = rtGetRenderResourceHandleIndex(h);
+    if (idx >= r_MaxRenderResources.sz)
+        return false;
+    const void *desc = NULL;
+    rtLockRead(&_description_tab.lock);
+    if (_description_tab.handles[idx].value == h.value) {
+        switch (type) {
+        case RT_RENDER_RESOURCE_TYPE_BUFFER:
+            desc = &_description_tab.descs[idx].buffer;
+            break;
+        case RT_RENDER_RESOURCE_TYPE_TEXTURE2D:
+            desc = &_description_tab.descs[idx].texture2d;
+            break;
+        default:
+            desc = NULL;
+            break;
+        }
+    }
+    rtUnlockRead(&_description_tab.lock);
+    return desc;
+}
+
+/* Returns a pointer to the resource description or NULL, if the handle does not refer to a valid buffer */
+const rt_render_buffer_desc *rtGetRenderBufferDescription(rt_render_resource_handle h) {
+    return GetResourceDescription(h);
+}
+
+/* Returns a pointer to the resource description or NULL, if the handle does not refer to a valid texture2d */
+const rt_render_texture2d_desc *rtGetRenderTexture2DDescription(rt_render_resource_handle h) {    
+    return GetResourceDescription(h);
+}
+
+static rt_render_resource_handle AllocSlot(rt_render_resource_type type, const void *desc) {
+    rt_render_resource_handle h = rtMakeRenderResourceHandle(RT_RENDER_RESOURCE_TYPE_INVALID, 0, 0);
+    rtLockWrite(&_description_tab.lock);
+    uint32_t slot = _description_tab.first_free;
+    if (slot < r_MaxRenderResources.sz) {
+        _description_tab.first_free = _description_tab.descs[slot].next_free;
+        uint32_t current_version = rtGetRenderResourceHandleVersion(_description_tab.handles[slot]);
+        uint32_t next_version = (current_version + 1) & RT_RENDER_RESOURCE_MAX_VERSION;
+        h = rtMakeRenderResourceHandle(type, next_version, slot);
+        _description_tab.handles[slot] = h;
+        switch (type) {
+        case RT_RENDER_RESOURCE_TYPE_BUFFER:
+            memcpy(&_description_tab.descs[slot].buffer, desc, sizeof(rt_render_buffer_desc));
+            break;
+        case RT_RENDER_RESOURCE_TYPE_TEXTURE2D:
+            memcpy(&_description_tab.descs[slot].texture2d, desc, sizeof(rt_render_texture2d_desc));
+            break;
+        default:
+            rtReportError("RENDERER", "Tried to create a resource with invalid type %u", type);
+            break;
+        }
+    }
+    rtUnlockWrite(&_description_tab.lock);
+    return h;
+}
+
+/* Stores the render buffer description and returns a handle to the new resource. */
+rt_render_resource_handle  rtCreateRenderBuffer(const rt_render_buffer_desc *desc) {
+    return AllocSlot(RT_RENDER_RESOURCE_TYPE_BUFFER, desc);
+}
+
+/* Stores the texture2d description and returns a handle to the new resource. */
+rt_render_resource_handle rtCreateRenderTexture2D(const rt_render_texture2d_desc *desc) {
+    return AllocSlot(RT_RENDER_RESOURCE_TYPE_TEXTURE2D, desc);
+}

src/renderer/virtual_resource_registry.h

@@ -0,0 +1,33 @@
+#ifndef RT_RENDERER_VIRTUAL_RESOURCE_REGISTRY_H
+#define RT_RENDERER_VIRTUAL_RESOURCE_REGISTRY_H
+
+#include <stdbool.h>
+#include <runtime/runtime.h>
+#include "render_resource.h"
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Returns true if the handle refers to an existing resource. */
+bool rtIsRenderResourceKnown(rt_render_resource_handle h);
+
+/* Returns a pointer to the resource description or NULL, if the handle does not refer to a valid buffer */
+const rt_render_buffer_desc *rtGetRenderBufferDescription(rt_render_resource_handle h);
+
+/* Returns a pointer to the resource description or NULL, if the handle does not refer to a valid texture2d */
+const rt_render_texture2d_desc *rtGetRenderTexture2DDescription(rt_render_resource_handle h);
+
+/* Stores the render buffer description and returns a handle to the new resource. */
+rt_render_resource_handle  rtCreateRenderBuffer(const rt_render_buffer_desc *desc);
+
+/* Stores the texture2d description and returns a handle to the new resource. */
+rt_render_resource_handle rtCreateRenderTexture2D(const rt_render_texture2d_desc *desc);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+