Textures: extract ImTextureDataQueueUpload() out of ImFontAtlasTextureBlockQueueUpload() (#8465) Not atlas specific, in support of texture system.

diff --git a/imgui.cpp b/imgui.cpp
index 34b2818..f4c4493 100644
--- a/imgui.cpp
+++ b/imgui.cpp

@@ -9013,7 +9013,7 @@
     return g.IO.FontDefault ? g.IO.FontDefault : atlas->Fonts[0];
 }
 
-// EXPERIMENTAL: DO NOT USE YET.
+// EXPERIMENTAL. Use ImTextureDataQueueUpload() to queue updates.
 void ImGui::RegisterUserTexture(ImTextureData* tex)
 {
     ImGuiContext& g = *GImGui;

diff --git a/imgui_draw.cpp b/imgui_draw.cpp
index c7415f9..cc497f3 100644
--- a/imgui_draw.cpp
+++ b/imgui_draw.cpp

@@ -2973,12 +2973,17 @@
         memcpy(dst_tex->GetPixelsAt(dst_x, dst_y + y), src_tex->GetPixelsAt(src_x, src_y + y), w * dst_tex->BytesPerPixel);
 }
 
-// Queue texture block update for renderer backend
 void ImFontAtlasTextureBlockQueueUpload(ImFontAtlas* atlas, ImTextureData* tex, int x, int y, int w, int h)
 {
+    ImTextureDataQueueUpload(tex, x, y, w, h);
+    atlas->TexIsBuilt = false;
+}
+
+// Queue texture block update for renderer backend
+void ImTextureDataQueueUpload(ImTextureData* tex, int x, int y, int w, int h)
+{
     IM_ASSERT(tex->Status != ImTextureStatus_WantDestroy && tex->Status != ImTextureStatus_Destroyed);
     IM_ASSERT(x >= 0 && x <= 0xFFFF && y >= 0 && y <= 0xFFFF && w >= 0 && x + w <= 0x10000 && h >= 0 && y + h <= 0x10000);
-    IM_UNUSED(atlas);
 
     ImTextureRect req = { (unsigned short)x, (unsigned short)y, (unsigned short)w, (unsigned short)h };
     int new_x1 = ImMax(tex->UpdateRect.w == 0 ? 0 : tex->UpdateRect.x + tex->UpdateRect.w, req.x + req.w);
@@ -2991,7 +2996,6 @@
     tex->UsedRect.y = ImMin(tex->UsedRect.y, req.y);
     tex->UsedRect.w = (unsigned short)(ImMax(tex->UsedRect.x + tex->UsedRect.w, req.x + req.w) - tex->UsedRect.x);
     tex->UsedRect.h = (unsigned short)(ImMax(tex->UsedRect.y + tex->UsedRect.h, req.y + req.h) - tex->UsedRect.y);
-    atlas->TexIsBuilt = false;
 
     // No need to queue if status is == ImTextureStatus_WantCreate
     if (tex->Status == ImTextureStatus_OK || tex->Status == ImTextureStatus_WantUpdates)

diff --git a/imgui_internal.h b/imgui_internal.h
index b3792ab..918b627 100644
--- a/imgui_internal.h
+++ b/imgui_internal.h

@@ -3215,7 +3215,7 @@
     IMGUI_API void          SetNextWindowRefreshPolicy(ImGuiWindowRefreshFlags flags);
 
     // Fonts, drawing
-    IMGUI_API void          RegisterUserTexture(ImTextureData* tex); // Register external texture. EXPERIMENTAL: DO NOT USE YET.
+    IMGUI_API void          RegisterUserTexture(ImTextureData* tex); // Register external texture. EXPERIMENTAL.
     IMGUI_API void          UnregisterUserTexture(ImTextureData* tex);
     IMGUI_API void          RegisterFontAtlas(ImFontAtlas* atlas);
     IMGUI_API void          UnregisterFontAtlas(ImFontAtlas* atlas);
@@ -3977,6 +3977,7 @@
 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 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);
 IMGUI_API const char*       ImTextureDataGetFormatName(ImTextureFormat format);