Add SDL backend

.github/workflows/build.yml

@@ -20,6 +20,7 @@ jobs:
           sudo apt-get -y update
           sudo apt install xorg-dev
 
+      # for GLFW
       - name: configure glfw
         run: cmake -S . -Bbuild
         working-directory: ./thirdparty/glfw
@@ -32,6 +33,20 @@ jobs:
         run: |
           cp -f ./thirdparty/glfw/build/src/libglfw3.a ./lib/linux/x64
 
+      # for SDL2
+      - name: configure sdl
+        run: cmake -S . -Bbuild
+        working-directory: ./thirdparty/SDL
+
+      - name: make sdl
+        run: make -j 4
+        working-directory: ./thirdparty/SDL/build
+
+      - name: copy sdl to lib
+        run: |
+          cp -f ./thirdparty/SDL/build//libSDL2.a ./lib/linux/x64
+
+      # for cimgui
       - name: configure cimgui
         run: cmake -Bbuild
         working-directory: ./lib
@@ -61,6 +76,7 @@ jobs:
     steps:
       - uses: actions/checkout@main
 
+      # glfw
       - name: configure glfw for x64
         run: cmake -S . -Bbuild -DCMAKE_OSX_ARCHITECTURES=x86_64
         working-directory: ./thirdparty/glfw
@@ -89,6 +105,36 @@ jobs:
         run: |
           cp -f ./thirdparty/glfw/build/src/libglfw3.a ./lib/macos/arm64
 
+      # sdl
+      - name: configure sdl for x64
+        run: cmake -S . -Bbuild -DCMAKE_OSX_ARCHITECTURES=x86_64
+        working-directory: ./thirdparty/SDL
+
+      - name: make sdl x84
+        run: make -j 4
+        working-directory: ./thirdparty/SDL/build
+
+      - name: copy sdl to lib
+        run: |
+          cp -f ./thirdparty/SDL/build/libSDL2.a ./lib/macos/x64
+
+      - name: clean sdl
+        run: cmake --build ./build --target clean
+        working-directory: ./thirdparty/SDL
+
+      - name: configure sdl for arm64
+        run: cmake -S . -Bbuild -DCMAKE_OSX_ARCHITECTURES=arm64
+        working-directory: ./thirdparty/SDL
+
+      - name: make sdl arm64
+        run: make -j 4
+        working-directory: ./thirdparty/SDL/build
+
+      - name: copy sdl to lib
+        run: |
+          cp -f ./thirdparty/SDL/build/libSDL2.a ./lib/macos/arm64
+
+      # cimgui
       - name: configure cimgui for x64
         run: cmake -Bbuild -DCMAKE_OSX_ARCHITECTURES=x86_64
         working-directory: ./lib
@@ -151,6 +197,7 @@ jobs:
             cmake:p
             ninja:p
 
+      # glfw
       - name: configure glfw
         run: cmake -G Ninja -S . -B build -DCMAKE_BUILD_TYPE=Release
         working-directory: ./thirdparty/glfw
@@ -162,6 +209,19 @@ jobs:
       - name: copy glfw to lib
         run: cp -f ./thirdparty/glfw/build/src/libglfw3.a ./lib/windows/x64
 
+      # sdl
+      - name: configure sdl
+        run: cmake -G Ninja -S . -B build -DCMAKE_BUILD_TYPE=Release
+        working-directory: ./thirdparty/SDL
+
+      - name: make sdl
+        run: cmake --build build -j 4
+        working-directory: ./thirdparty/SDL
+
+      - name: copy sdl to lib
+        run: cp -f ./thirdparty/SDL/build/libSDL2.a ./lib/windows/x64
+
+      # cimgui
       - name: configure cimgui
         run: cmake -G Ninja -B build
         working-directory: .\lib

backend.go

@@ -15,6 +15,8 @@ import (
 	"unsafe"
 )
 
+type voidCallbackFunc func()
+
 var currentBackend backendCExpose
 
 // TODO: Maybe we should get rid of it?

extra_types.h

@@ -1,5 +1,7 @@
 #pragma once
 
+typedef void (*VoidCallback)();
+
 #ifdef __WIN32
 typedef unsigned long long xulong;
 typedef long long xlong;

glfw_backend.cpp

@@ -161,7 +161,7 @@ void glfw_render(GLFWwindow *window, VoidCallback renderLoop) {
   glfwSwapBuffers(window);
 }
 
-void igRunLoop(GLFWwindow *window, VoidCallback loop, VoidCallback beforeRender, VoidCallback afterRender,
+void igGLFWRunLoop(GLFWwindow *window, VoidCallback loop, VoidCallback beforeRender, VoidCallback afterRender,
                VoidCallback beforeDestroyContext) {
   glfwMakeContextCurrent(window);
   ImGuiIO *io = igGetIO();

glfw_backend.go

@@ -180,8 +180,6 @@ const (
 	GLFWModNumLock  = GLFWModifierKey(C.GLFWModNumLock)
 )
 
-type voidCallbackFunc func()
-
 var _ Backend[GLFWWindowFlags] = &GLFWBackend{}
 
 type GLFWBackend struct {
@@ -248,7 +246,7 @@ func (b *GLFWBackend) SetBgColor(color Vec4) {
 
 func (b *GLFWBackend) Run(loop func()) {
 	b.loop = loop
-	C.igRunLoop(b.handle(), C.VoidCallback(C.loopCallback), C.VoidCallback(C.beforeRender), C.VoidCallback(C.afterRender), C.VoidCallback(C.beforeDestoryContext))
+	C.igGLFWRunLoop(b.handle(), C.VoidCallback(C.loopCallback), C.VoidCallback(C.beforeRender), C.VoidCallback(C.afterRender), C.VoidCallback(C.beforeDestoryContext))
 }
 
 func (b *GLFWBackend) loopFunc() func() {

glfw_backend.h

@@ -2,6 +2,7 @@
 
 #include "cimgui_wrapper.h"
 #include "thirdparty/glfw/include/GLFW/glfw3.h" // Will drag system OpenGL headers
+#include "extra_types.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -170,14 +171,12 @@ struct GLFWwindow;
 struct GLFWmonitor;
 struct GLFWimage;
 
-typedef void (*VoidCallback)();
-
 extern void igSetBgColor(ImVec4 color);
 extern void igSetTargetFPS(unsigned int fps);
 extern int igInitGLFW();
 extern GLFWwindow *igCreateGLFWWindow(const char *title, int width, int height,
                                       VoidCallback afterCreateContext);
-extern void igRunLoop(GLFWwindow *window, VoidCallback loop, VoidCallback beforeRender, VoidCallback afterRender,
+extern void igGLFWRunLoop(GLFWwindow *window, VoidCallback loop, VoidCallback beforeRender, VoidCallback afterRender,
                       VoidCallback beforeDestroyContext);
 extern void igGLFWWindow_GetDisplaySize(GLFWwindow *window, int *width, int *height);
 extern void igGLFWWindow_GetContentScale(GLFWwindow *window, float *width, float *height);

lib/CMakeLists.txt

@@ -44,6 +44,12 @@ set(GLFW3_INCLUDE_DIR ${GLFW3_PREFIX}/include)
 list(APPEND IMGUI_SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/../cimgui/imgui/backends/imgui_impl_glfw.cpp)
 list(APPEND IMGUI_LIBRARIES glfw)
 
+#SDL
+set(SDL2_PREFIX ${CMAKE_CURRENT_SOURCE_DIR}/../thirdparty/SDL)
+set(SDL2_INCLUDE_DIR ${SDL2_PREFIX}/include)
+list(APPEND IMGUI_SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/../cimgui/imgui/backends/imgui_impl_sdl2.cpp)
+list(APPEND IMGUI_LIBRARIES sdl2)
+
 #opengl3
 list(APPEND IMGUI_SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/../cimgui/imgui/backends/imgui_impl_opengl3.cpp)
 include_directories(${CMAKE_CURRENT_SOURCE_DIR}/../cimgui/imgui/examples/libs/gl3w)
@@ -77,6 +83,7 @@ target_compile_definitions(cimgui PUBLIC IMGUI_IMPL_API=extern\t\"C\"\t)
 target_include_directories(cimgui PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/../cimgui/)
 target_include_directories(cimgui PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/../cimgui/imgui)
 target_include_directories(cimgui PUBLIC ${GLFW3_INCLUDE_DIR})
+target_include_directories(cimgui PUBLIC ${SDL2_INCLUDE_DIR})
 set_target_properties(cimgui PROPERTIES PREFIX "")
 target_link_libraries(cimgui ${IMGUI_LIBRARIES})