Backends: SDL_Renderer: Amend 1d2d246, various tweaks, fixes, sync to latest. (#3926)

backends/imgui_impl_sdl.cpp

@@ -251,11 +251,6 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window)
     return true;
 }
 
-bool ImGui_ImplSDL2_InitForSDLRenderer(SDL_Window* window)
-{
-    return ImGui_ImplSDL2_Init(window);
-}
-
 bool ImGui_ImplSDL2_InitForOpenGL(SDL_Window* window, void* sdl_gl_context)
 {
     IM_UNUSED(sdl_gl_context); // Viewport branch will need this.
@@ -283,6 +278,11 @@ bool ImGui_ImplSDL2_InitForMetal(SDL_Window* window)
     return ImGui_ImplSDL2_Init(window);
 }
 
+bool ImGui_ImplSDL2_InitForSDLRenderer(SDL_Window* window)
+{
+    return ImGui_ImplSDL2_Init(window);
+}
+
 void ImGui_ImplSDL2_Shutdown()
 {
     ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();

backends/imgui_impl_sdl.h

@@ -21,11 +21,11 @@
 struct SDL_Window;
 typedef union SDL_Event SDL_Event;
 
-IMGUI_IMPL_API bool     ImGui_ImplSDL2_InitForSDLRenderer(SDL_Window* window);
 IMGUI_IMPL_API bool     ImGui_ImplSDL2_InitForOpenGL(SDL_Window* window, void* sdl_gl_context);
 IMGUI_IMPL_API bool     ImGui_ImplSDL2_InitForVulkan(SDL_Window* window);
 IMGUI_IMPL_API bool     ImGui_ImplSDL2_InitForD3D(SDL_Window* window);
 IMGUI_IMPL_API bool     ImGui_ImplSDL2_InitForMetal(SDL_Window* window);
+IMGUI_IMPL_API bool     ImGui_ImplSDL2_InitForSDLRenderer(SDL_Window* window);
 IMGUI_IMPL_API void     ImGui_ImplSDL2_Shutdown();
 IMGUI_IMPL_API void     ImGui_ImplSDL2_NewFrame();
 IMGUI_IMPL_API bool     ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event);

backends/imgui_impl_sdlrenderer.cpp

@@ -1,15 +1,21 @@
-// dear imgui: Renderer Backend for SDL_Renderer, with Platform Backend SDL 
+// dear imgui: Renderer Backend for SDL_Renderer
 // (Requires: SDL 2.0.17+)
 
+// Important to understand: SDL_Renderer is an _optional_ component of SDL. We do not recommend you use SDL_Renderer
+// because it provide a rather limited API to the end-user. We provide this backend for the sake of completeness.
+// For a multi-platform app consider using e.g. SDL+DirectX on Windows and SDL+OpenGL on Linux/OSX.
+
 // Implemented features:
+//  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
+// Missing features:
+//  [ ] Renderer: Support for large meshes (64k+ vertices) with 16-bit indices.
 
 // You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
 // Read online: https://github.com/ocornut/imgui/tree/master/docs
 
-
 // CHANGELOG
-//  2021-16-03: Creation 
+//  2021-09-21: Initial version.
 
 #include "imgui.h"
 #include "imgui_impl_sdlrenderer.h"
@@ -19,16 +25,17 @@
 #include <stdint.h>     // intptr_t
 #endif
 
-#include "SDL.h"
-
-#if SDL_MAJOR_VERSION < 2 || SDL_MINOR_VERSION < 0 || SDL_PATCHLEVEL < 17
-#  error Requires: SDL 2.0.17+ because of SDL_RenderGeometry function
+// SDL
+#include <SDL.h>
+#if !SDL_VERSION_ATLEAST(2,0,17)
+#error This backend requires SDL 2.0.17+ because of SDL_RenderGeometry() function
 #endif
 
+// SDL_Renderer data
 struct ImGui_ImplSDLRenderer_Data
 {
-    SDL_Renderer *SDLRenderer;
-    SDL_Texture  *FontTexture;
+    SDL_Renderer*   SDLRenderer;
+    SDL_Texture*    FontTexture;
     ImGui_ImplSDLRenderer_Data() { memset(this, 0, sizeof(*this)); }
 };
 
@@ -40,7 +47,7 @@ static ImGui_ImplSDLRenderer_Data* ImGui_ImplSDLRenderer_GetBackendData()
 }
 
 // Functions
-bool ImGui_ImplSDLRenderer_Init(SDL_Renderer *renderer)
+bool ImGui_ImplSDLRenderer_Init(SDL_Renderer* renderer)
 {
     ImGuiIO& io = ImGui::GetIO();
     IM_ASSERT(io.BackendRendererUserData == NULL && "Already initialized a renderer backend!");
@@ -49,16 +56,18 @@ bool ImGui_ImplSDLRenderer_Init(SDL_Renderer *renderer)
     // Setup backend capabilities flags
     ImGui_ImplSDLRenderer_Data* bd = IM_NEW(ImGui_ImplSDLRenderer_Data)();
     io.BackendRendererUserData = (void*)bd;
-    io.BackendRendererName = "imgui_impl_SDLRenderer";
+    io.BackendRendererName = "imgui_impl_sdlrenderer";
 
     bd->SDLRenderer = renderer;
+
     return true;
 }
 
 void ImGui_ImplSDLRenderer_Shutdown()
 {
-    ImGuiIO& io = ImGui::GetIO();
     ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
+    IM_ASSERT(bd != NULL && "No renderer backend to shutdown, or already shutdown?");
+    ImGuiIO& io = ImGui::GetIO();
 
     ImGui_ImplSDLRenderer_DestroyDeviceObjects();
 
@@ -69,9 +78,10 @@ void ImGui_ImplSDLRenderer_Shutdown()
 
 static void ImGui_ImplSDLRenderer_SetupRenderState()
 {
-	ImGui_ImplSDLRenderer_Data *bd = ImGui_ImplSDLRenderer_GetBackendData();
+	ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
 
-	// Clear out any viewports and cliprects set by the user
+	// Clear out any viewports and cliprect set by the user
+    // FIXME: Technically speaking there are lots of other things we could backup/setup/restore during our render process.
 	SDL_RenderSetViewport(bd->SDLRenderer, NULL);
 	SDL_RenderSetClipRect(bd->SDLRenderer, NULL);
 }
@@ -81,9 +91,8 @@ void ImGui_ImplSDLRenderer_NewFrame()
     ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
     IM_ASSERT(bd != NULL && "Did you call ImGui_ImplSDLRenderer_Init()?");
 
-    if (!bd->FontTexture) {
+    if (!bd->FontTexture)
         ImGui_ImplSDLRenderer_CreateDeviceObjects();
-    }
 }
 
 void ImGui_ImplSDLRenderer_RenderDrawData(ImDrawData* draw_data)
@@ -91,35 +100,33 @@ void ImGui_ImplSDLRenderer_RenderDrawData(ImDrawData* draw_data)
 	ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
 
 	// If there's a scale factor set by the user, use that instead
-	float rsX = 1.0f;
-	float rsY = 1.0f;
-	SDL_RenderGetScale(bd->SDLRenderer, &rsX, &rsY);
-
-	ImVec2 renderScale;
-	// If the user has specified a scale factor to SDL_Renderer already (via SDL_RenderSetScale()), SDL will scale whatever we pass
-	// to SDL_RenderGeometryRaw() by that scale factor. In that case we don't want to be also scaling it ourselves here.
-	renderScale.x = (rsX == 1.0f) ? draw_data->FramebufferScale.x : 1.0f;
-	renderScale.y = (rsY == 1.0f) ? draw_data->FramebufferScale.y : 1.0f;
+    // If the user has specified a scale factor to SDL_Renderer already via SDL_RenderSetScale(), SDL will scale whatever we pass
+    // to SDL_RenderGeometryRaw() by that scale factor. In that case we don't want to be also scaling it ourselves here.
+    float rsx = 1.0f;
+	float rsy = 1.0f;
+	SDL_RenderGetScale(bd->SDLRenderer, &rsx, &rsy);
+    ImVec2 render_scale;
+	render_scale.x = (rsx == 1.0f) ? draw_data->FramebufferScale.x : 1.0f;
+	render_scale.y = (rsy == 1.0f) ? draw_data->FramebufferScale.y : 1.0f;
 
 	// Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
-	int fb_width = (int)(draw_data->DisplaySize.x * renderScale.x);
-	int fb_height = (int)(draw_data->DisplaySize.y * renderScale.y);
+	int fb_width = (int)(draw_data->DisplaySize.x * render_scale.x);
+	int fb_height = (int)(draw_data->DisplaySize.y * render_scale.y);
 	if (fb_width == 0 || fb_height == 0)
 		return;
 
-
 	// Will project scissor/clipping rectangles into framebuffer space
 	ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
-	ImVec2 clip_scale = renderScale;
+	ImVec2 clip_scale = render_scale;
 
+    // Render command lists
     ImGui_ImplSDLRenderer_SetupRenderState();
-
-    for (int n = 0; n < draw_data->CmdListsCount; n++) {
-
+    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    {
         const ImDrawList* cmd_list = draw_data->CmdLists[n];
         const ImDrawVert* vtx_buffer = cmd_list->VtxBuffer.Data;
         const ImDrawIdx* idx_buffer = cmd_list->IdxBuffer.Data;
-        
+
         for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
         {
             const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
@@ -127,53 +134,39 @@ void ImGui_ImplSDLRenderer_RenderDrawData(ImDrawData* draw_data)
             {
                 // User callback, registered via ImDrawList::AddCallback()
                 // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
-                if (pcmd->UserCallback == ImDrawCallback_ResetRenderState) {
+                if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
                     ImGui_ImplSDLRenderer_SetupRenderState();
-                } else { 
+                else
                     pcmd->UserCallback(cmd_list, pcmd);
-                }
             }
             else
             {
                 // Project scissor/clipping rectangles into framebuffer space
-                ImVec4 clip_rect;
-                clip_rect.x = (pcmd->ClipRect.x - clip_off.x) * clip_scale.x;
-                clip_rect.y = (pcmd->ClipRect.y - clip_off.y) * clip_scale.y;
-                clip_rect.z = (pcmd->ClipRect.z - clip_off.x) * clip_scale.x;
-                clip_rect.w = (pcmd->ClipRect.w - clip_off.y) * clip_scale.y;
-
-                if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
-                {
-                    SDL_Rect r;
-                    r.x = clip_rect.x;
-                    r.y = clip_rect.y;
-                    r.w = clip_rect.z - clip_rect.x;
-                    r.h = clip_rect.w - clip_rect.y;
-
-                    SDL_RenderSetClipRect(bd->SDLRenderer, &r);
-
-
-                    int xy_stride = sizeof(ImDrawVert);
-                    float *xy = (float *)((char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, pos));
-
-                    int uv_stride = sizeof(ImDrawVert);
-                    float *uv = (float*)((char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, uv));
-
-                    int col_stride = sizeof(ImDrawVert);
-                    int *color = (int*)((char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, col));
-
-					SDL_Texture *tex = (SDL_Texture*)pcmd->TextureId;
-
-                    SDL_RenderGeometryRaw(bd->SDLRenderer, tex, 
-                            xy, xy_stride, color,
-                            col_stride, 
-                            uv, uv_stride, 
-                            cmd_list->VtxBuffer.Size,
-                            idx_buffer, pcmd->ElemCount, sizeof (ImDrawIdx));
-
-                }
+                ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
+                ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
+                if (clip_min.x < 0.0f) { clip_min.x = 0.0f; }
+                if (clip_min.y < 0.0f) { clip_min.y = 0.0f; }
+                if (clip_max.x > fb_width) { clip_max.x = (float)fb_width; }
+                if (clip_max.y > fb_height) { clip_max.y = (float)fb_height; }
+                if (clip_max.x < clip_min.x || clip_max.y < clip_min.y)
+                    continue;
+
+                SDL_Rect r = { (int)(clip_min.x), (int)(clip_min.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y) };
+                SDL_RenderSetClipRect(bd->SDLRenderer, &r);
+
+                const float* xy = (const float*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, pos));
+                const float* uv = (const float*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, uv));
+                const int* color = (const int*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, col));
+
+                // Bind texture, Draw
+				SDL_Texture* tex = (SDL_Texture*)pcmd->GetTexID();
+                SDL_RenderGeometryRaw(bd->SDLRenderer, tex,
+                    xy, (int)sizeof(ImDrawVert),
+                    color, (int)sizeof(ImDrawVert),
+                    uv, (int)sizeof(ImDrawVert),
+                    cmd_list->VtxBuffer.Size,
+                    idx_buffer + pcmd->IdxOffset, pcmd->ElemCount, sizeof(ImDrawIdx));
             }
-            idx_buffer += pcmd->ElemCount;
         }
     }
 }
@@ -181,19 +174,24 @@ void ImGui_ImplSDLRenderer_RenderDrawData(ImDrawData* draw_data)
 // Called by Init/NewFrame/Shutdown
 bool ImGui_ImplSDLRenderer_CreateFontsTexture()
 {
-    // Build texture atlas
     ImGuiIO& io = ImGui::GetIO();
     ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
+
+    // Build texture atlas
     unsigned char* pixels;
     int width, height;
     io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);   // Load as RGBA 32-bit (75% of the memory is wasted, but default font is so small) because it is more likely to be compatible with user's existing shaders. If your ImTextureId represent a higher-level concept than just a GL texture id, consider calling GetTexDataAsAlpha8() instead to save on GPU memory.
+
+    // Upload texture to graphics system
     bd->FontTexture = SDL_CreateTexture(bd->SDLRenderer, SDL_PIXELFORMAT_RGBA32, SDL_TEXTUREACCESS_STATIC, width, height);
-    if (bd->FontTexture == NULL) {
+    if (bd->FontTexture == NULL)
+    {
         SDL_Log("error creating texture");
         return false;
     }
     SDL_UpdateTexture(bd->FontTexture, NULL, pixels, 4 * width);
     SDL_SetTextureBlendMode(bd->FontTexture, SDL_BLENDMODE_BLEND);
+
     // Store our identifier
     io.Fonts->SetTexID((ImTextureID)(intptr_t)bd->FontTexture);
 
@@ -204,7 +202,8 @@ void ImGui_ImplSDLRenderer_DestroyFontsTexture()
 {
     ImGuiIO& io = ImGui::GetIO();
     ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
-    if (bd->FontTexture) {
+    if (bd->FontTexture)
+    {
         io.Fonts->SetTexID(0);
         SDL_DestroyTexture(bd->FontTexture);
         bd->FontTexture = NULL;
@@ -220,4 +219,3 @@ void ImGui_ImplSDLRenderer_DestroyDeviceObjects()
 {
     ImGui_ImplSDLRenderer_DestroyFontsTexture();
 }
-

backends/imgui_impl_sdlrenderer.h

@@ -1,13 +1,21 @@
-// dear imgui: Renderer Backend for SDL using SDL_Renderer
+// dear imgui: Renderer Backend for SDL_Renderer
 // (Requires: SDL 2.0.17+)
 
+// Important to understand: SDL_Renderer is an _optional_ component of SDL. We do not recommend you use SDL_Renderer
+// because it provide a rather limited API to the end-user. We provide this backend for the sake of completeness.
+// For a multi-platform app consider using e.g. SDL+DirectX on Windows and SDL+OpenGL on Linux/OSX.
+
+// Implemented features:
+//  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
+// Missing features:
+//  [ ] Renderer: Support for large meshes (64k+ vertices) with 16-bit indices.
 
 #pragma once
 #include "imgui.h"      // IMGUI_IMPL_API
 
 struct SDL_Renderer;
 
-IMGUI_IMPL_API bool     ImGui_ImplSDLRenderer_Init(SDL_Renderer *renderer);
+IMGUI_IMPL_API bool     ImGui_ImplSDLRenderer_Init(SDL_Renderer* renderer);
 IMGUI_IMPL_API void     ImGui_ImplSDLRenderer_Shutdown();
 IMGUI_IMPL_API void     ImGui_ImplSDLRenderer_NewFrame();
 IMGUI_IMPL_API void     ImGui_ImplSDLRenderer_RenderDrawData(ImDrawData* draw_data);

docs/BACKENDS.md

@@ -75,7 +75,7 @@ List of Renderer Backends:
     imgui_impl_metal.mm       ; Metal (with ObjC)
     imgui_impl_opengl2.cpp    ; OpenGL 2 (legacy, fixed pipeline <- don't use with modern OpenGL context)
     imgui_impl_opengl3.cpp    ; OpenGL 3/4, OpenGL ES 2, OpenGL ES 3 (modern programmable pipeline)
-    imgui_impl_sdlrenderer.cpp; use SDL2 and SDL_Renderer, any SDL backend (opengl, gles, gles2, d3d9, d3d11, metal or software) can be used underneath
+    imgui_impl_sdlrenderer.cpp; SDL_Renderer (optional component of SDL2 available from SDL 2.0.18+)
     imgui_impl_vulkan.cpp     ; Vulkan
     imgui_impl_wgpu.cpp       ; WebGPU
 

docs/CHANGELOG.txt

@@ -84,10 +84,12 @@ Other Changes:
 - Backends: Added more implicit asserts to detect invalid/redundant calls to Shutdown functions. (#4562)
 - Backends: OpenGL3: Fixed our custom GL loader conflicting with user using GL3W. (#4445) [@rokups]
 - Backends: WebGPU: Fixed for latest specs. (#4472) [@Kangz]
+- Backends: SDL_Renderer: Added SDL_Renderer backend compatible with upcoming SDL 2.0.18. (#3926) [@1bsyl]
 - Backends: Metal: Fixed a crash when clipping rect larger than framebuffer is submitted via
   a direct unclipped PushClipRect() call. (#4464)
 - Backends: OSX: Use mach_absolute_time as CFAbsoluteTimeGetCurrent can jump backwards. (#4557, #4563) [@lfnoise]
 - Backends: All renderers: Normalize clipping rect handling across backends. (#4464)
+- Examples: Added SDL + SDL_Renderer example in "examples/example_sdl_sdlrenderer/" folder. (#3926) [@1bsyl]
 
 
 -----------------------------------------------------------------------

docs/EXAMPLES.md

@@ -130,11 +130,6 @@ This uses more modern OpenGL calls and custom shaders. <BR>
 This may actually also work with OpenGL 2.x contexts! <BR>
 Prefer using that if you are using modern OpenGL in your application (anything with shaders).
 
-[example_sdl_sdlrenderer/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl_sdlrenderer/) <BR>
-Use SDL2 and SDL_Renderer, any SDL backend (opengl, gles, gles2, d3d9, d3d11, metal or software) can be used underneath <BR>
-= main.cpp + imgui_impl_sdl.cpp + imgui_impl_sdlrenderer.cpp <BR>
-It requires SDL 2.0.17+
-
 [example_glfw_vulkan/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_vulkan/) <BR>
 GLFW (Win32, Mac, Linux) + Vulkan example. <BR>
 = main.cpp + imgui_impl_glfw.cpp + imgui_impl_vulkan.cpp <BR>
@@ -180,6 +175,12 @@ SDL2 (Win32, Mac, Linux, etc.) + OpenGL3+/ES2/ES3 example. <BR>
 This uses more modern OpenGL calls and custom shaders. <BR>
 This may actually also work with OpenGL 2.x contexts! <BR>
 
+[example_sdl_sdlrenderer/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl_sdlrenderer/) <BR>
+SDL2 (Win32, Mac, Linux, etc.) + SDL_Renderer (most graphics backends are supported underneath) <BR>
+= main.cpp + imgui_impl_sdl.cpp + imgui_impl_sdlrenderer.cpp <BR>
+This requires SDL 2.0.17+ (expected to release November 2021) <BR>
+We do not really recommend using SDL_Renderer as it is a rather primitive API.
+
 [example_sdl_vulkan/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl_vulkan/) <BR>
 SDL2 (Win32, Mac, Linux, etc.) + Vulkan example. <BR>
 = main.cpp + imgui_impl_sdl.cpp + imgui_impl_vulkan.cpp <BR>

examples/example_sdl_sdlrenderer/README.md

@@ -6,7 +6,7 @@
 ```
 set SDL2_DIR=path_to_your_sdl2_folder
 cl /Zi /MD /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl.cpp ..\..\backends\imgui_impl_sdlrenderer.cpp ..\..\imgui*.cpp /FeDebug/example_sdl_sdlrenderer.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x86 SDL2.lib SDL2main.lib /subsystem:console
-#          ^^ include paths                  ^^ source files                                                           ^^ output exe                    ^^ output dir   ^^ libraries
+#          ^^ include paths                  ^^ source files                                                                                        ^^ output exe                        ^^ output dir  ^^ libraries
 # or for 64-bit:
 cl /Zi /MD /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl.cpp ..\..\backends\imgui_impl_sdlrenderer.cpp ..\..\imgui*.cpp /FeDebug/example_sdl_sdlrenderer.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x64 SDL2.lib SDL2main.lib /subsystem:console
 ```

examples/example_sdl_sdlrenderer/example_sdl_sdlrenderer.vcxproj

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -28,27 +28,27 @@
     <ConfigurationType>Application</ConfigurationType>
     <UseDebugLibraries>true</UseDebugLibraries>
     <CharacterSet>MultiByte</CharacterSet>
-    <PlatformToolset>v110</PlatformToolset>
+    <PlatformToolset>v140</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseDebugLibraries>true</UseDebugLibraries>
     <CharacterSet>MultiByte</CharacterSet>
-    <PlatformToolset>v110</PlatformToolset>
+    <PlatformToolset>v140</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseDebugLibraries>false</UseDebugLibraries>
     <WholeProgramOptimization>true</WholeProgramOptimization>
     <CharacterSet>MultiByte</CharacterSet>
-    <PlatformToolset>v110</PlatformToolset>
+    <PlatformToolset>v140</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseDebugLibraries>false</UseDebugLibraries>
     <WholeProgramOptimization>true</WholeProgramOptimization>
     <CharacterSet>MultiByte</CharacterSet>
-    <PlatformToolset>v110</PlatformToolset>
+    <PlatformToolset>v140</PlatformToolset>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
@@ -178,4 +178,4 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
+</Project>

examples/example_sdl_sdlrenderer/main.cpp

@@ -3,8 +3,9 @@
 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
 // Read online: https://github.com/ocornut/imgui/tree/master/docs
 
-// See imgui_impl_sdl.cpp for details.
-// (Requires: SDL 2.0.17+)
+// Important to understand: SDL_Renderer is an _optional_ component of SDL. We do not recommend you use SDL_Renderer
+// because it provide a rather limited API to the end-user. We provide this backend for the sake of completeness.
+// For a multi-platform app consider using e.g. SDL+DirectX on Windows and SDL+OpenGL on Linux/OSX.
 
 #include "imgui.h"
 #include "imgui_impl_sdl.h"
@@ -12,8 +13,8 @@
 #include <stdio.h>
 #include <SDL.h>
 
-#if SDL_MAJOR_VERSION < 2 || SDL_MINOR_VERSION < 0 || SDL_PATCHLEVEL < 17
-#  error Requires: SDL 2.0.17+ because of SDL_RenderGeometry function
+#if !SDL_VERSION_ATLEAST(2,0,17)
+#error This backend requires SDL 2.0.17+ because of SDL_RenderGeometry() function
 #endif
 
 // Main code
@@ -28,18 +29,20 @@ int main(int, char**)
         return -1;
     }
 
-    // SDL_SetHint(SDL_HINT_RENDER_DRIVER, "opengles2");
-    // SDL_SetHint(SDL_HINT_RENDER_DRIVER, "opengl");
-    // SDL_SetHint(SDL_HINT_RENDER_DRIVER, "software");
-
     // Setup window
-    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
-    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
-    SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
-    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
     SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+SDL_Renderer example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
+
+    // Setup SDL_Renderer instance
+    SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED);
+    if (renderer == NULL)
+    {
+        SDL_Log("Error creating SDL_Renderer!");
+        return false;
+    }
+    //SDL_RendererInfo info;
+    //SDL_GetRendererInfo(renderer, &info);
+    //SDL_Log("Current SDL_Renderer: %s", info.name);
 
     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
@@ -54,17 +57,6 @@ int main(int, char**)
 
     // Setup Platform/Renderer backends
     ImGui_ImplSDL2_InitForSDLRenderer(window);
-
-    SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED);
-    if (renderer == NULL) {
-        SDL_Log("Error creating SDL renderer");
-        return false;
-    } else {
-        SDL_RendererInfo info;
-        SDL_GetRendererInfo(renderer, &info);
-        SDL_Log("Current SDL Renderer: %s", info.name);
-    }
-
     ImGui_ImplSDLRenderer_Init(renderer);
 
     // Load Fonts
@@ -150,8 +142,9 @@ int main(int, char**)
 
         // Rendering
         ImGui::Render();
+        SDL_SetRenderDrawColor(renderer, (Uint8)(clear_color.x * 255), (Uint8)(clear_color.y * 255), (Uint8)(clear_color.z * 255), (Uint8)(clear_color.w * 255));
+        SDL_RenderClear(renderer);
         ImGui_ImplSDLRenderer_RenderDrawData(ImGui::GetDrawData());
-
         SDL_RenderPresent(renderer);
     }