Textures: extract ImTextureDataUpdateNewFrame() out of ImFontAtlasUpdateNewFrame(). (#8465)

imgui_draw.cpp

@@ -2817,48 +2817,12 @@ void ImFontAtlasUpdateNewFrame(ImFontAtlas* atlas, int frame_count, bool rendere
     // Update texture status
     for (int tex_n = 0; tex_n < atlas->TexList.Size; tex_n++)
     {
+        // Update and remove if requested
         ImTextureData* tex = atlas->TexList[tex_n];
-        bool remove_from_list = false;
-        if (tex->Status == ImTextureStatus_OK)
-        {
-            tex->Updates.resize(0);
-            tex->UpdateRect.x = tex->UpdateRect.y = (unsigned short)~0;
-            tex->UpdateRect.w = tex->UpdateRect.h = 0;
-        }
         if (tex->Status == ImTextureStatus_WantCreate && atlas->RendererHasTextures)
             IM_ASSERT(tex->TexID == ImTextureID_Invalid && tex->BackendUserData == NULL && "Backend set texture's TexID/BackendUserData but did not update Status to OK.");
 
-        // Request destroy
+        bool remove_from_list = ImTextureDataUpdateNewFrame(tex);
-        // - Keep bool to true in order to differentiate a planned destroy vs a destroy decided by the backend.
-        // - We don't destroy pixels right away, as backend may have an in-flight copy from RAM.
-        if (tex->WantDestroyNextFrame && tex->Status != ImTextureStatus_Destroyed && tex->Status != ImTextureStatus_WantDestroy)
-        {
-            IM_ASSERT(tex->Status == ImTextureStatus_OK || tex->Status == ImTextureStatus_WantCreate || tex->Status == ImTextureStatus_WantUpdates);
-            tex->Status = ImTextureStatus_WantDestroy;
-        }
-
-        // If a texture has never reached the backend, they don't need to know about it.
-        // (note: backends between 1.92.0 and 1.92.4 could set an already destroyed texture to ImTextureStatus_WantDestroy
-        //  when invalidating graphics objects twice, which would previously remove it from the list and crash.)
-        if (tex->Status == ImTextureStatus_WantDestroy && tex->TexID == ImTextureID_Invalid && tex->BackendUserData == NULL)
-            tex->Status = ImTextureStatus_Destroyed;
-
-        // Process texture being destroyed
-        if (tex->Status == ImTextureStatus_Destroyed)
-        {
-            IM_ASSERT(tex->TexID == ImTextureID_Invalid && tex->BackendUserData == NULL && "Backend set texture Status to Destroyed but did not clear TexID/BackendUserData!");
-            if (tex->WantDestroyNextFrame)
-                remove_from_list = true; // Destroy was scheduled by us
-            else
-                tex->Status = ImTextureStatus_WantCreate; // Destroy was done was backend: recreate it (e.g. freed resources mid-run)
-        }
-
-        // The backend may need defer destroying by a few frames, to handle texture used by previous in-flight rendering.
-        // We allow the texture staying in _WantDestroy state and increment a counter which the backend can use to take its decision.
-        if (tex->Status == ImTextureStatus_WantDestroy)
-            tex->UnusedFrames++;
-
-        // Destroy and remove
         if (remove_from_list)
         {
             IM_ASSERT(atlas->TexData != tex);
@@ -2870,6 +2834,49 @@ void ImFontAtlasUpdateNewFrame(ImFontAtlas* atlas, int frame_count, bool rendere
     }
 }
 
+bool ImTextureDataUpdateNewFrame(ImTextureData* tex)
+{
+    bool remove_from_list = false;
+    if (tex->Status == ImTextureStatus_OK)
+    {
+        tex->Updates.resize(0);
+        tex->UpdateRect.x = tex->UpdateRect.y = (unsigned short)~0;
+        tex->UpdateRect.w = tex->UpdateRect.h = 0;
+    }
+
+    // Request destroy
+    // - Keep bool to true in order to differentiate a planned destroy vs a destroy decided by the backend.
+    // - We don't destroy pixels right away, as backend may have an in-flight copy from RAM.
+    if (tex->WantDestroyNextFrame && tex->Status != ImTextureStatus_Destroyed && tex->Status != ImTextureStatus_WantDestroy)
+    {
+        IM_ASSERT(tex->Status == ImTextureStatus_OK || tex->Status == ImTextureStatus_WantCreate || tex->Status == ImTextureStatus_WantUpdates);
+        tex->Status = ImTextureStatus_WantDestroy;
+    }
+
+    // If a texture has never reached the backend, they don't need to know about it.
+    // (note: backends between 1.92.0 and 1.92.4 could set an already destroyed texture to ImTextureStatus_WantDestroy
+    //  when invalidating graphics objects twice, which would previously remove it from the list and crash.)
+    if (tex->Status == ImTextureStatus_WantDestroy && tex->TexID == ImTextureID_Invalid && tex->BackendUserData == NULL)
+        tex->Status = ImTextureStatus_Destroyed;
+
+    // Process texture being destroyed
+    if (tex->Status == ImTextureStatus_Destroyed)
+    {
+        IM_ASSERT(tex->TexID == ImTextureID_Invalid && tex->BackendUserData == NULL && "Backend set texture Status to Destroyed but did not clear TexID/BackendUserData!");
+        if (tex->WantDestroyNextFrame)
+            remove_from_list = true; // Destroy was scheduled by us
+        else
+            tex->Status = ImTextureStatus_WantCreate; // Destroy was done was backend: recreate it (e.g. freed resources mid-run)
+    }
+
+    // The backend may need defer destroying by a few frames, to handle texture used by previous in-flight rendering.
+    // We allow the texture staying in _WantDestroy state and increment a counter which the backend can use to take its decision.
+    if (tex->Status == ImTextureStatus_WantDestroy)
+        tex->UnusedFrames++;
+
+    return remove_from_list;
+}
+
 void ImFontAtlasTextureBlockConvert(const unsigned char* src_pixels, ImTextureFormat src_fmt, int src_pitch, unsigned char* dst_pixels, ImTextureFormat dst_fmt, int dst_pitch, int w, int h)
 {
     IM_ASSERT(src_pixels != NULL && dst_pixels != NULL);

imgui_internal.h

@@ -1702,6 +1702,7 @@ enum ImGuiActivateFlags_
 };
 
 // Early work-in-progress API for ScrollToItem()
+// FIXME: Missing flags to request making both edges visible when possible.
 enum ImGuiScrollFlags_
 {
     ImGuiScrollFlags_None                   = 0,
@@ -3979,6 +3980,7 @@ IMGUI_API void              ImFontAtlasTextureBlockFill(ImTextureData* dst_tex,
 IMGUI_API void              ImFontAtlasTextureBlockCopy(ImTextureData* src_tex, int src_x, int src_y, ImTextureData* dst_tex, int dst_x, int dst_y, int w, int h);
 IMGUI_API void              ImFontAtlasTextureBlockQueueUpload(ImFontAtlas* atlas, ImTextureData* tex, int x, int y, int w, int h);
 
+IMGUI_API bool              ImTextureDataUpdateNewFrame(ImTextureData* tex);
 IMGUI_API void              ImTextureDataQueueUpload(ImTextureData* tex, int x, int y, int w, int h);
 IMGUI_API int               ImTextureDataGetFormatBytesPerPixel(ImTextureFormat format);
 IMGUI_API const char*       ImTextureDataGetStatusName(ImTextureStatus status);