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Backends: DX9, DX10, DX11, DX12, Allegro5, OpenGL2, OpenGL3, SDLRenderer2, SDLRenderer3, SDLGPU3, Vulkan: added standard draw callbacks when possible. (#9378)

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This commit is contained in:
omar
2026-04-23 21:50:45 +02:00
committed by ocornut
parent 82f46a73f8
commit 0a811e8ea1
19 changed files with 244 additions and 45 deletions
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backends/imgui_impl_opengl3.cpp
+43 -3
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@@ -23,6 +23,7 @@
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2026-XX-XX: OpenGL: Added support for standard draw callbacks (in platform_io): DrawCallback_ResetRenderState, DrawCallback_SetSamplerLinear, DrawCallback_SetSamplerNearest, DrawCallback_SetSamplerCustom.
// 2026-03-12: OpenGL: Fixed invalid assert in ImGui_ImplOpenGL3_UpdateTexture() if ImTextureID_Invalid is defined to be != 0, which became the default since 2026-03-12. (#9295)
// 2025-12-11: OpenGL: Fixed embedded loader multiple init/shutdown cycles broken on some platforms. (#8792, #9112)
// 2025-09-18: Call platform_io.ClearRendererHandlers() on shutdown.
@@ -252,6 +253,12 @@ struct ImGui_ImplOpenGL3_Data
bool HasBindSampler;
bool HasClipOrigin;
bool UseBufferSubData;
bool UseTexParameterToSetSampler;
GLuint NextSampler;
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
GLuint TexSamplers[2]; // Linear, Nearest
#endif
ImVector<char> TempBuffer;
ImGui_ImplOpenGL3_Data() { memset((void*)this, 0, sizeof(*this)); }
@@ -378,7 +385,7 @@ static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_wid
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
if (bd->HasBindSampler)
glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 and GL ES 3.0 may set that otherwise.
glBindSampler(0, bd->TexSamplers[0]); // We use combined texture/sampler state. Applications using GL 3.3 and GL ES 3.0 may set that otherwise.
#endif
(void)vertex_array_object;
@@ -397,6 +404,12 @@ static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_wid
GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)offsetof(ImDrawVert, col)));
}
// Draw callbacks
static void ImGui_ImplOpenGL3_DrawCallback_ResetRenderState(const ImDrawList*, const ImDrawCmd*) {} // Intentionally empty. Used as an identifier for rendering loop to call its code. Simpler to implement this way.
static void ImGui_ImplOpenGL3_DrawCallback_SetSamplerLinear(const ImDrawList*, const ImDrawCmd*) { ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData(); if (bd->HasBindSampler) { glBindSampler(0, bd->TexSamplers[0]); } else { bd->UseTexParameterToSetSampler = true; bd->NextSampler = GL_LINEAR; } }
static void ImGui_ImplOpenGL3_DrawCallback_SetSamplerNearest(const ImDrawList*, const ImDrawCmd*) { ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData(); if (bd->HasBindSampler) { glBindSampler(0, bd->TexSamplers[1]); } else { bd->UseTexParameterToSetSampler = true; bd->NextSampler = GL_NEAREST; } }
static void ImGui_ImplOpenGL3_DrawCallback_SetSamplerCustom(const ImDrawList*, const ImDrawCmd* cmd){ ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData(); if (bd->HasBindSampler) { glBindSampler(0, (GLuint)(intptr_t)cmd->UserCallbackData); } }
// OpenGL3 Render function.
// Note that this implementation is little overcomplicated because we are saving/setting up/restoring every OpenGL state explicitly.
// This is in order to be able to run within an OpenGL engine that doesn't do so.
@@ -511,8 +524,7 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
if (pcmd->UserCallback != nullptr)
{
// 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 == ImGui_ImplOpenGL3_DrawCallback_ResetRenderState)
ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
else
pcmd->UserCallback(draw_list, pcmd);
@@ -530,6 +542,15 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
// Bind texture, Draw
GL_CALL(glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->GetTexID()));
// Emulate sampler change (even though it is technically part of texture data)
// As a sort of hack/workaround, we only start writing using glTextParameter() if sampler is ever changed explicitly.
if (!bd->HasBindSampler && bd->UseTexParameterToSetSampler)
{
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, bd->NextSampler);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, bd->NextSampler);
}
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
if (bd->GlVersion >= 320)
GL_CALL(glDrawElementsBaseVertex(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx)), (GLint)pcmd->VtxOffset));
@@ -895,6 +916,20 @@ bool ImGui_ImplOpenGL3_CreateDeviceObjects()
glGenBuffers(1, &bd->VboHandle);
glGenBuffers(1, &bd->ElementsHandle);
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
if (bd->HasBindSampler)
{
glGenSamplers(2, &bd->TexSamplers[0]);
for (int sampler_n = 0; sampler_n < 2; sampler_n++)
{
GL_CALL(glSamplerParameteri(bd->TexSamplers[sampler_n], GL_TEXTURE_MIN_FILTER, (sampler_n == 0) ? GL_LINEAR : GL_NEAREST));
GL_CALL(glSamplerParameteri(bd->TexSamplers[sampler_n], GL_TEXTURE_MAG_FILTER, (sampler_n == 0) ? GL_LINEAR : GL_NEAREST));
GL_CALL(glSamplerParameteri(bd->TexSamplers[sampler_n], GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE));
GL_CALL(glSamplerParameteri(bd->TexSamplers[sampler_n], GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE));
}
}
#endif
// Restore modified GL state
glBindTexture(GL_TEXTURE_2D, last_texture);
glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
@@ -912,6 +947,7 @@ void ImGui_ImplOpenGL3_DestroyDeviceObjects()
{
ImGui_ImplOpenGL3_InitLoader();
ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
if (bd->TexSamplers[0]) { glDeleteSamplers(2, &bd->TexSamplers[0]); bd->TexSamplers[0] = bd->TexSamplers[1] = 0; }
if (bd->VboHandle) { glDeleteBuffers(1, &bd->VboHandle); bd->VboHandle = 0; }
if (bd->ElementsHandle) { glDeleteBuffers(1, &bd->ElementsHandle); bd->ElementsHandle = 0; }
if (bd->ShaderHandle) { glDeleteProgram(bd->ShaderHandle); bd->ShaderHandle = 0; }
@@ -991,6 +1027,10 @@ bool ImGui_ImplOpenGL3_Init(const char* glsl_version)
ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
platform_io.Renderer_TextureMaxWidth = platform_io.Renderer_TextureMaxHeight = (int)bd->MaxTextureSize;
platform_io.DrawCallback_ResetRenderState = ImGui_ImplOpenGL3_DrawCallback_ResetRenderState;
platform_io.DrawCallback_SetSamplerLinear = ImGui_ImplOpenGL3_DrawCallback_SetSamplerLinear;
platform_io.DrawCallback_SetSamplerNearest = ImGui_ImplOpenGL3_DrawCallback_SetSamplerNearest;
platform_io.DrawCallback_SetSamplerCustom = ImGui_ImplOpenGL3_DrawCallback_SetSamplerCustom;
// Store GLSL version string so we can refer to it later in case we recreate shaders.
// Note: GLSL version is NOT the same as GL version. Leave this to nullptr if unsure.