| 1 | // dear imgui: Renderer Backend for OpenGL2 (legacy OpenGL, fixed pipeline) |
| 2 | // This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..) |
| 3 | |
| 4 | // Implemented features: |
| 5 | // [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture as texture identifier. Read the FAQ about ImTextureID/ImTextureRef! |
| 6 | // [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures). |
| 7 | // [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'. |
| 8 | // Missing features or Issues: |
| 9 | // [ ] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset). |
| 10 | // [ ] Renderer: Use of DrawCallback_SetSamplerLinear, DrawCallback_SetSamplerNearest is emulated by poking to glTexParameter(), as legacy OpenGL doesn't have glBindSampler(). |
| 11 | |
| 12 | // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this. |
| 13 | // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need. |
| 14 | // Learn about Dear ImGui: |
| 15 | // - FAQ https://dearimgui.com/faq |
| 16 | // - Getting Started https://dearimgui.com/getting-started |
| 17 | // - Documentation https://dearimgui.com/docs (same as your local docs/ folder). |
| 18 | // - Introduction, links and more at the top of imgui.cpp |
| 19 | |
| 20 | // **DO NOT USE THIS CODE IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)** |
| 21 | // **Prefer using the code in imgui_impl_opengl3.cpp** |
| 22 | // This code is mostly provided as a reference to learn how ImGui integration works, because it is shorter to read. |
| 23 | // If your code is using GL3+ context or any semi modern OpenGL calls, using this is likely to make everything more |
| 24 | // complicated, will require your code to reset every single OpenGL attributes to their initial state, and might |
| 25 | // confuse your GPU driver. |
| 26 | // The GL2 code is unable to reset attributes or even call e.g. "glUseProgram(0)" because they don't exist in that API. |
| 27 | |
| 28 | #pragma once |
| 29 | #include "imgui.h" // IMGUI_IMPL_API |
| 30 | #ifndef IMGUI_DISABLE |
| 31 | |
| 32 | // Follow "Getting Started" link and check examples/ folder to learn about using backends! |
| 33 | IMGUI_IMPL_API bool ImGui_ImplOpenGL2_Init(); |
| 34 | IMGUI_IMPL_API void ImGui_ImplOpenGL2_Shutdown(); |
| 35 | IMGUI_IMPL_API void ImGui_ImplOpenGL2_NewFrame(); |
| 36 | IMGUI_IMPL_API void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data); |
| 37 | |
| 38 | // Called by Init/NewFrame/Shutdown |
| 39 | IMGUI_IMPL_API bool ImGui_ImplOpenGL2_CreateDeviceObjects(); |
| 40 | IMGUI_IMPL_API void ImGui_ImplOpenGL2_DestroyDeviceObjects(); |
| 41 | |
| 42 | // (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually. |
| 43 | IMGUI_IMPL_API void ImGui_ImplOpenGL2_UpdateTexture(ImTextureData* tex); |
| 44 | |
| 45 | #endif // #ifndef IMGUI_DISABLE |