Backends, Examples: removed Emscripten < 4.0.10 support. Removed IMGUI_IMPL_WEBGPU_BACKEND_WGPU. (#9281, #8381)

- This commit removes the option of using -sUSE_WEBGPU=1 from CMake and make - Compiling with a version of Emscripten >= 4.0.10 will work the same way as it was before - Compiling with a version of Emscripten < 4.0.10 will print an error message and abort the build (in the case of CMake) - Since there can only be 1 implementation for the backend in the case of Emscripten, this commit cleans the code accordingly
2026-03-27 23:37:03 -05:00 · 2026-03-05 09:33:21 -08:00
parent 6f8bdb7bf7
commit e92820db2a
14 changed files with 24 additions and 161 deletions
--- a/examples/example_glfw_wgpu/CMakeLists.txt
+++ b/examples/example_glfw_wgpu/CMakeLists.txt
@@ -52,23 +52,15 @@ set(IMGUI_EXAMPLE_SOURCE_FILES
 )

 if(EMSCRIPTEN)
-    if(NOT IMGUI_EMSCRIPTEN_WEBGPU_FLAG) # if IMGUI_EMSCRIPTEN_WEBGPU_FLAG not used, set by current EMSCRIPTEN version
-        if(EMSCRIPTEN_VERSION VERSION_GREATER_EQUAL "4.0.10")
-            set(IMGUI_EMSCRIPTEN_WEBGPU_FLAG "--use-port=emdawnwebgpu" CACHE STRING "Choose between --use-port=emdawnwebgpu (Dawn implementation of EMSCRIPTEN) and -sUSE_WEBGPU=1 (WGPU implementation of EMSCRIPTEN, deprecated in 4.0.10): default to --use-port=emdawnwebgpu for EMSCRIPTEN >= 4.0.10")
-        else()
-            set(IMGUI_EMSCRIPTEN_WEBGPU_FLAG "-sUSE_WEBGPU=1" CACHE STRING "Use -sUSE_WEBGPU=1 for EMSCRIPTEN WGPU implementation")
-        endif()
-    else() # if IMGUI_EMSCRIPTEN_WEBGPU_FLAG used, check correct version
-        if(EMSCRIPTEN_VERSION VERSION_LESS "4.0.10" AND "${IMGUI_EMSCRIPTEN_WEBGPU_FLAG}" MATCHES "emdawnwebgpu")
-            # it's necessary EMSCRIPTEN >= v4.0.10 (although "--use-port=path/to/emdawnwebgpu.port.py" is supported/tested from v4.0.8)
-            message(FATAL_ERROR "emdawnwebgpu needs EMSCRIPTEN version >= 4.0.10")
-        endif()
+    if(EMSCRIPTEN_VERSION VERSION_GREATER_EQUAL "4.0.10")
+        set(IMGUI_EMSCRIPTEN_WEBGPU_FLAG "--use-port=emdawnwebgpu" CACHE STRING "Default to --use-port=emdawnwebgpu. You can override to provide your own local port.")
+    else()
+        message(FATAL_ERROR "emdawnwebgpu needs EMSCRIPTEN version >= 4.0.10")
    endif()

-    if(EMSCRIPTEN_VERSION VERSION_GREATER_EQUAL "3.1.57")
+    if(NOT IMGUI_EMSCRIPTEN_GLFW3)
+        # Defaults to contrib.glfw3 because Emscripten version is > 3.1.57
        set(IMGUI_EMSCRIPTEN_GLFW3 "--use-port=contrib.glfw3" CACHE STRING "Choose between --use-port=contrib.glfw3 and -sUSE_GLFW=3 for GLFW implementation (default to --use-port=contrib.glfw3)")
-    else() # cannot use contrib.glfw3 prior to 3.1.57
-        set(IMGUI_EMSCRIPTEN_GLFW3 "-sUSE_GLFW=3" CACHE STRING "Use -sUSE_GLFW=3 for GLFW implementation" FORCE)
    endif()

    set(LIBRARIES glfw)
@@ -165,7 +157,6 @@ endif()
 # In this example IMGUI_IMPL_WEBGPU_BACKEND_DAWN / IMGUI_IMPL_WEBGPU_BACKEND_WGPU internal define is set according to:
 #   EMSCRIPTEN: by used FLAG
 #     --use-port=emdawnwebgpu --> IMGUI_IMPL_WEBGPU_BACKEND_DAWN defined
-#     -sUSE_WEBGPU=1          --> IMGUI_IMPL_WEBGPU_BACKEND_WGPU defined
 #   NATIVE: by used SDK installation directory
 #     if IMGUI_DAWN_DIR is valid --> IMGUI_IMPL_WEBGPU_BACKEND_DAWN defined
 #     if IMGUI_WGPU_DIR is valid --> IMGUI_IMPL_WEBGPU_BACKEND_WGPU defined
@@ -191,12 +182,8 @@ else() # Emscripten settings
    endif()
    message(STATUS "Using ${IMGUI_EMSCRIPTEN_GLFW3} GLFW implementation")

-    if("${IMGUI_EMSCRIPTEN_WEBGPU_FLAG}" MATCHES "emdawnwebgpu")
-        target_compile_options(${IMGUI_EXECUTABLE} PUBLIC "${IMGUI_EMSCRIPTEN_WEBGPU_FLAG}")
-        target_compile_definitions(${IMGUI_EXECUTABLE} PUBLIC "IMGUI_IMPL_WEBGPU_BACKEND_DAWN")
-    else()
-        target_compile_definitions(${IMGUI_EXECUTABLE} PUBLIC "IMGUI_IMPL_WEBGPU_BACKEND_WGPU")
-    endif()
+    target_compile_options(${IMGUI_EXECUTABLE} PUBLIC "${IMGUI_EMSCRIPTEN_WEBGPU_FLAG}")
+    target_compile_definitions(${IMGUI_EXECUTABLE} PUBLIC "IMGUI_IMPL_WEBGPU_BACKEND_DAWN")
    message(STATUS "Using ${IMGUI_EMSCRIPTEN_WEBGPU_FLAG} WebGPU implementation")

    target_link_options(${IMGUI_EXECUTABLE} PRIVATE
--- a/examples/example_glfw_wgpu/Makefile.emscripten
+++ b/examples/example_glfw_wgpu/Makefile.emscripten
@@ -40,11 +40,7 @@ LDFLAGS += -s ASYNCIFY=1
 LDFLAGS += -s NO_EXIT_RUNTIME=0
 LDFLAGS += -s ASSERTIONS=1

-# (1) Using legacy WebGPU implementation (Emscripten < 4.0.10)
-#EMS += -DIMGUI_IMPL_WEBGPU_BACKEND_WGPU
-#LDFLAGS += -s USE_WEBGPU=1
-
-# or (2) Using newer Dawn-based WebGPU port (Emscripten >= 4.0.10)
+# Using Dawn-based WebGPU port (requires Emscripten >= 4.0.10)
 EMS += --use-port=emdawnwebgpu
 LDFLAGS += --use-port=emdawnwebgpu

--- a/examples/example_glfw_wgpu/README.md
+++ b/examples/example_glfw_wgpu/README.md
@@ -60,12 +60,7 @@ For the WASM code produced by Emscripten to work correctly, it will also be nece
 CMake checks the EMSCRIPEN version then:
   - if EMS >= 4.0.10 uses `--use-port=emdawnwebgpu` flag to build  
      - it set `IMGUI_IMPL_WEBGPU_BACKEND_DAWN` compiler define 
-   - if EMS < 4.0.10 uses `-sUSE_WEBGPU=1` flag to build
-      - it set `IMGUI_IMPL_WEBGPU_BACKEND_WGPU` compiler define 
-
-#### Generate Emscripten forcing `-sUSE_WEBGPU=1` deprecated flag even with EMS >= 4.0.10
- `emcmake cmake -G Ninja -DIMGUI_EMSCRIPTEN_WEBGPU_FLAG="-sUSE_WEBGPU=1" -B where_to_build_dir`
-   - it set `IMGUI_IMPL_WEBGPU_BACKEND_WGPU` compiler define 
+   - if EMS < 4.0.10 the build aborts (`-sUSE_WEBGPU=1` is no longer supported in ImGui)

 #### Generate Emscripten using external WebGPU library (emdawnwebgpu_pkg)
 - `emcmake cmake -G Ninja -DIMGUI_EMSCRIPTEN_WEBGPU_FLAG="--use-port=path_to_emdawnwebgpu_pkg" -B where_to_build_dir`
--- a/examples/example_glfw_wgpu/main.cpp
+++ b/examples/example_glfw_wgpu/main.cpp
@@ -19,9 +19,6 @@
 #ifdef __EMSCRIPTEN__
 #include <emscripten.h>
 #include <emscripten/html5.h>
-#if defined(IMGUI_IMPL_WEBGPU_BACKEND_WGPU)
-#include <emscripten/html5_webgpu.h>
-#endif
 #include "../libs/emscripten/emscripten_mainloop_stub.h"
 #endif

--- a/examples/example_sdl2_wgpu/CMakeLists.txt
+++ b/examples/example_sdl2_wgpu/CMakeLists.txt
@@ -52,17 +52,10 @@ set(IMGUI_EXAMPLE_SOURCE_FILES
 )

 if(EMSCRIPTEN)
-    if(NOT IMGUI_EMSCRIPTEN_WEBGPU_FLAG) # if IMGUI_EMSCRIPTEN_WEBGPU_FLAG not used, set by current EMSCRIPTEN version
-        if(EMSCRIPTEN_VERSION VERSION_GREATER_EQUAL "4.0.10")
-            set(IMGUI_EMSCRIPTEN_WEBGPU_FLAG "--use-port=emdawnwebgpu" CACHE STRING "Choose between --use-port=emdawnwebgpu (Dawn implementation of EMSCRIPTEN) and -sUSE_WEBGPU=1 (WGPU implementation of EMSCRIPTEN, deprecated in 4.0.10): default to --use-port=emdawnwebgpu for EMSCRIPTEN >= 4.0.10")
-        else()
-            set(IMGUI_EMSCRIPTEN_WEBGPU_FLAG "-sUSE_WEBGPU=1" CACHE STRING "Use -sUSE_WEBGPU=1 for EMSCRIPTEN WGPU implementation")
-        endif()
-    else() # if IMGUI_EMSCRIPTEN_WEBGPU_FLAG used, check correct version
-        if(EMSCRIPTEN_VERSION VERSION_LESS "4.0.10" AND "${IMGUI_EMSCRIPTEN_WEBGPU_FLAG}" MATCHES "emdawnwebgpu")
-            # it's necessary EMSCRIPTEN >= v4.0.10 (although "--use-port=path/to/emdawnwebgpu.port.py" is supported/tested from v4.0.8)
-            message(FATAL_ERROR "emdawnwebgpu needs EMSCRIPTEN version >= 4.0.10")
-        endif()
+    if(EMSCRIPTEN_VERSION VERSION_GREATER_EQUAL "4.0.10")
+        set(IMGUI_EMSCRIPTEN_WEBGPU_FLAG "--use-port=emdawnwebgpu" CACHE STRING "Default to --use-port=emdawnwebgpu. You can override to provide your own local port.")
+    else()
+        message(FATAL_ERROR "emdawnwebgpu needs EMSCRIPTEN version >= 4.0.10")
    endif()

    add_compile_options(-sDISABLE_EXCEPTION_CATCHING=1 -DIMGUI_DISABLE_FILE_FUNCTIONS=1)
@@ -160,7 +153,6 @@ endif()
 # IMGUI_IMPL_WEBGPU_BACKEND_DAWN/WGPU internal define is set according to:
 #   EMSCRIPTEN: by used FLAG
 #     --use-port=emdawnwebgpu --> IMGUI_IMPL_WEBGPU_BACKEND_DAWN enabled (+EMSCRIPTEN)
-#     -sUSE_WEBGPU=1          --> IMGUI_IMPL_WEBGPU_BACKEND_WGPU enabled (+EMSCRIPTEN)
 #   NATIVE: by used SDK installation directory
 #     if IMGUI_DAWN_DIR is valid --> IMGUI_IMPL_WEBGPU_BACKEND_DAWN enabled
 #     if IMGUI_WGPU_DIR is valid --> IMGUI_IMPL_WEBGPU_BACKEND_WGPU enabled
@@ -180,12 +172,8 @@ if(NOT EMSCRIPTEN) # WegGPU-Native settings
 else() # Emscripten settings
    set(CMAKE_EXECUTABLE_SUFFIX ".html")

-    if("${IMGUI_EMSCRIPTEN_WEBGPU_FLAG}" MATCHES "emdawnwebgpu")
-        target_compile_options(${IMGUI_EXECUTABLE} PUBLIC "${IMGUI_EMSCRIPTEN_WEBGPU_FLAG}")
-        target_compile_definitions(${IMGUI_EXECUTABLE} PUBLIC "IMGUI_IMPL_WEBGPU_BACKEND_DAWN")
-    else()
-        target_compile_definitions(${IMGUI_EXECUTABLE} PUBLIC "IMGUI_IMPL_WEBGPU_BACKEND_WGPU")
-    endif()
+    target_compile_options(${IMGUI_EXECUTABLE} PUBLIC "${IMGUI_EMSCRIPTEN_WEBGPU_FLAG}")
+    target_compile_definitions(${IMGUI_EXECUTABLE} PUBLIC "IMGUI_IMPL_WEBGPU_BACKEND_DAWN")
    message(STATUS "Using ${IMGUI_EMSCRIPTEN_WEBGPU_FLAG} WebGPU implementation")

    target_compile_options(${IMGUI_EXECUTABLE} PUBLIC "-sUSE_SDL=2")
--- a/examples/example_sdl2_wgpu/Makefile.emscripten
+++ b/examples/example_sdl2_wgpu/Makefile.emscripten
@@ -40,11 +40,7 @@ LDFLAGS += -s ASYNCIFY=1
 LDFLAGS += -s NO_EXIT_RUNTIME=0
 LDFLAGS += -s ASSERTIONS=1

-# (1) Using legacy WebGPU implementation (Emscripten < 4.0.10)
-#EMS += -DIMGUI_IMPL_WEBGPU_BACKEND_WGPU
-#LDFLAGS += -s USE_WEBGPU=1
-
-# or (2) Using newer Dawn-based WebGPU port (Emscripten >= 4.0.10)
+# Using Dawn-based WebGPU port (requires Emscripten >= 4.0.10)
 EMS += --use-port=emdawnwebgpu
 LDFLAGS += --use-port=emdawnwebgpu

--- a/examples/example_sdl2_wgpu/README.md
+++ b/examples/example_sdl2_wgpu/README.md
@@ -60,12 +60,7 @@ For the WASM code produced by Emscripten to work correctly, it will also be nece
 CMake checks the EMSCRIPEN version then:
   - if EMS >= 4.0.10 uses `--use-port=emdawnwebgpu` flag to build  
      - it set `IMGUI_IMPL_WEBGPU_BACKEND_DAWN` compiler define 
-   - if EMS < 4.0.10 uses `-sUSE_WEBGPU=1` flag to build
-      - it set `IMGUI_IMPL_WEBGPU_BACKEND_WGPU` compiler define 
-
-#### Generate Emscripten forcing `-sUSE_WEBGPU=1` deprecated flag even with EMS >= 4.0.10
- `emcmake cmake -G Ninja -DIMGUI_EMSCRIPTEN_WEBGPU_FLAG="-sUSE_WEBGPU=1" -B where_to_build_dir`
-   - it set `IMGUI_IMPL_WEBGPU_BACKEND_WGPU` compiler define 
+   - if EMS < 4.0.10 the build aborts (`-sUSE_WEBGPU=1` is no longer supported in ImGui)

 #### Generate Emscripten using external WebGPU library (emdawnwebgpu_pkg)
 - `emcmake cmake -G Ninja -DIMGUI_EMSCRIPTEN_WEBGPU_FLAG="--use-port=path_to_emdawnwebgpu_pkg" -B where_to_build_dir`
--- a/examples/example_sdl2_wgpu/main.cpp
+++ b/examples/example_sdl2_wgpu/main.cpp
@@ -18,9 +18,6 @@
 #ifdef __EMSCRIPTEN__
 #include <emscripten.h>
 #include <emscripten/html5.h>
-#if defined(IMGUI_IMPL_WEBGPU_BACKEND_WGPU)
-#include <emscripten/html5_webgpu.h>
-#endif
 #include "../libs/emscripten/emscripten_mainloop_stub.h"
 #endif

--- a/examples/example_sdl3_wgpu/CMakeLists.txt
+++ b/examples/example_sdl3_wgpu/CMakeLists.txt
@@ -55,18 +55,8 @@ if(EMSCRIPTEN)
    if(EMSCRIPTEN_VERSION VERSION_LESS "4.0.15")
        message(FATAL_ERROR "Using Emscripten with SDL3 needs Emscripten version >= 4.0.15")
    endif()
-    if(NOT IMGUI_EMSCRIPTEN_WEBGPU_FLAG) # if IMGUI_EMSCRIPTEN_WEBGPU_FLAG not used, set by current EMSCRIPTEN version
-        if(EMSCRIPTEN_VERSION VERSION_GREATER_EQUAL "4.0.10")
-            set(IMGUI_EMSCRIPTEN_WEBGPU_FLAG "--use-port=emdawnwebgpu" CACHE STRING "Choose between --use-port=emdawnwebgpu (Dawn implementation of EMSCRIPTEN) and -sUSE_WEBGPU=1 (WGPU implementation of EMSCRIPTEN, deprecated in 4.0.10): default to --use-port=emdawnwebgpu for EMSCRIPTEN >= 4.0.10")
-        else()
-            set(IMGUI_EMSCRIPTEN_WEBGPU_FLAG "-sUSE_WEBGPU=1" CACHE STRING "Use -sUSE_WEBGPU=1 for EMSCRIPTEN WGPU implementation")
-        endif()
-    else() # if IMGUI_EMSCRIPTEN_WEBGPU_FLAG used, check correct version
-        if(EMSCRIPTEN_VERSION VERSION_LESS "4.0.10" AND "${IMGUI_EMSCRIPTEN_WEBGPU_FLAG}" MATCHES "emdawnwebgpu")
-            # it's necessary EMSCRIPTEN >= v4.0.10 (although "--use-port=path/to/emdawnwebgpu.port.py" is supported/tested from v4.0.8)
-            message(FATAL_ERROR "emdawnwebgpu needs EMSCRIPTEN version >= 4.0.10")
-        endif()
-    endif()
+    # emdawnwebgpu was introduced in 4.0.10 so, due to the prior requirement, this will work
+    set(IMGUI_EMSCRIPTEN_WEBGPU_FLAG "--use-port=emdawnwebgpu" CACHE STRING "Default to --use-port=emdawnwebgpu. You can override to provide your own local port.")

    add_compile_options(-sDISABLE_EXCEPTION_CATCHING=1 -DIMGUI_DISABLE_FILE_FUNCTIONS=1)
 else() # Native/Desktop build
@@ -162,7 +152,6 @@ endif()
 # IMGUI_IMPL_WEBGPU_BACKEND_DAWN/WGPU internal define is set according to:
 #   EMSCRIPTEN: by used FLAG
 #     --use-port=emdawnwebgpu --> IMGUI_IMPL_WEBGPU_BACKEND_DAWN enabled (+EMSCRIPTEN)
-#     -sUSE_WEBGPU=1          --> IMGUI_IMPL_WEBGPU_BACKEND_WGPU enabled (+EMSCRIPTEN)
 #   NATIVE: by used SDK installation directory
 #     if IMGUI_DAWN_DIR is valid --> IMGUI_IMPL_WEBGPU_BACKEND_DAWN enabled
 #     if IMGUI_WGPU_DIR is valid --> IMGUI_IMPL_WEBGPU_BACKEND_WGPU enabled
@@ -182,12 +171,8 @@ if(NOT EMSCRIPTEN) # WegGPU-Native settings
 else() # Emscripten settings
    set(CMAKE_EXECUTABLE_SUFFIX ".html")

-    if("${IMGUI_EMSCRIPTEN_WEBGPU_FLAG}" MATCHES "emdawnwebgpu")
-        target_compile_options(${IMGUI_EXECUTABLE} PUBLIC "${IMGUI_EMSCRIPTEN_WEBGPU_FLAG}")
-        target_compile_definitions(${IMGUI_EXECUTABLE} PUBLIC "IMGUI_IMPL_WEBGPU_BACKEND_DAWN")
-    else()
-        target_compile_definitions(${IMGUI_EXECUTABLE} PUBLIC "IMGUI_IMPL_WEBGPU_BACKEND_WGPU")
-    endif()
+    target_compile_options(${IMGUI_EXECUTABLE} PUBLIC "${IMGUI_EMSCRIPTEN_WEBGPU_FLAG}")
+    target_compile_definitions(${IMGUI_EXECUTABLE} PUBLIC "IMGUI_IMPL_WEBGPU_BACKEND_DAWN")
    message(STATUS "Using ${IMGUI_EMSCRIPTEN_WEBGPU_FLAG} WebGPU implementation")

    target_compile_options(${IMGUI_EXECUTABLE} PUBLIC "-sUSE_SDL=3")
--- a/examples/example_sdl3_wgpu/Makefile.emscripten
+++ b/examples/example_sdl3_wgpu/Makefile.emscripten
@@ -40,11 +40,7 @@ LDFLAGS += -s ASYNCIFY=1
 LDFLAGS += -s NO_EXIT_RUNTIME=0
 LDFLAGS += -s ASSERTIONS=1

-# (1) Using legacy WebGPU implementation (Emscripten < 4.0.10)
-#EMS += -DIMGUI_IMPL_WEBGPU_BACKEND_WGPU
-#LDFLAGS += -s USE_WEBGPU=1
-
-# or (2) Using newer Dawn-based WebGPU port (Emscripten >= 4.0.10)
+# Using Dawn-based WebGPU port (requires Emscripten >= 4.0.10)
 EMS += --use-port=emdawnwebgpu
 LDFLAGS += --use-port=emdawnwebgpu

--- a/examples/example_sdl3_wgpu/README.md
+++ b/examples/example_sdl3_wgpu/README.md
@@ -60,12 +60,7 @@ For the WASM code produced by Emscripten to work correctly, it will also be nece
 CMake checks the EMSCRIPEN version then:
   - if EMS >= 4.0.10 uses `--use-port=emdawnwebgpu` flag to build  
      - it set `IMGUI_IMPL_WEBGPU_BACKEND_DAWN` compiler define 
-   - if EMS < 4.0.10 uses `-sUSE_WEBGPU=1` flag to build
-      - it set `IMGUI_IMPL_WEBGPU_BACKEND_WGPU` compiler define 
-
-#### Generate Emscripten forcing `-sUSE_WEBGPU=1` deprecated flag even with EMS >= 4.0.10
- `emcmake cmake -G Ninja -DIMGUI_EMSCRIPTEN_WEBGPU_FLAG="-sUSE_WEBGPU=1" -B where_to_build_dir`
-   - it set `IMGUI_IMPL_WEBGPU_BACKEND_WGPU` compiler define 
+   - if EMS < 4.0.10 the build aborts (`-sUSE_WEBGPU=1` is no longer supported in ImGui)

 #### Generate Emscripten using external WebGPU library (emdawnwebgpu_pkg)
 - `emcmake cmake -G Ninja -DIMGUI_EMSCRIPTEN_WEBGPU_FLAG="--use-port=path_to_emdawnwebgpu_pkg" -B where_to_build_dir`
--- a/examples/example_sdl3_wgpu/main.cpp
+++ b/examples/example_sdl3_wgpu/main.cpp
@@ -20,9 +20,6 @@
 #ifdef __EMSCRIPTEN__
 #include <emscripten.h>
 #include <emscripten/html5.h>
-#if defined(IMGUI_IMPL_WEBGPU_BACKEND_WGPU)
-#include <emscripten/html5_webgpu.h>
-#endif
 #include "../libs/emscripten/emscripten_mainloop_stub.h"
 #endif