ImDrawList merging commands with same texture

imgui.cpp

@@ -5928,11 +5928,12 @@ void ImDrawList::Clear()
 
 void ImDrawList::SetClipRect(const ImVec4& clip_rect)
 {
-    if (!commands.empty() && commands.back().vtx_count == 0)
+    ImDrawCmd* current_cmd = commands.empty() ? NULL : &commands.back();
+    if (current_cmd && current_cmd->vtx_count == 0)
     {
         // Reuse existing command (high-level clipping may have discarded vertices submitted earlier)
         // FIXME-OPT: Possibly even reuse previous command.
-        commands.back().clip_rect = clip_rect;
+        current_cmd->clip_rect = clip_rect;
     }
     else
     {
@@ -5959,11 +5960,12 @@ void ImDrawList::PopClipRect()
 
 void ImDrawList::SetTextureID(const ImTextureID& texture_id)
 {
-    if (!commands.empty() && commands.back().vtx_count == 0)
+    ImDrawCmd* current_cmd = commands.empty() ? NULL : &commands.back();
+    if (current_cmd && (current_cmd->vtx_count == 0 || current_cmd->texture_id == texture_id))
     {
-        // Reuse existing command (high-level clipping may have discarded vertices submitted earlier)
+        // Reuse existing command
         // FIXME-OPT: Possibly even reuse previous command.
-        commands.back().texture_id = texture_id;
+        current_cmd->texture_id = texture_id;
     }
     else
     {