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WIP - Backends: OpenGL2: added ImGuiBackendFlags_RendererHasTextures support.

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ocornut 2024-12-18 14:05:55 +01:00
parent 0cf0bd27f7
commit bd985153e6
2 changed files with 76 additions and 54 deletions
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122
backends/imgui_impl_opengl2.cpp
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@ -2,7 +2,8 @@
// This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..)
// Implemented features:
// [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
// [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture as texture identifier. Read the FAQ about ImTextureID/ImTextureRef!
// [X] Renderer: Texture updates support for dynamic font system (ImGuiBackendFlags_RendererHasTextures).
// [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
// Missing features or Issues:
// [ ] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
@ -83,8 +84,6 @@
// OpenGL data
struct ImGui_ImplOpenGL2_Data
{
GLuint FontTexture;
ImGui_ImplOpenGL2_Data() { memset((void*)this, 0, sizeof(*this)); }
};
@ -110,7 +109,8 @@ bool ImGui_ImplOpenGL2_Init()
ImGui_ImplOpenGL2_Data* bd = IM_NEW(ImGui_ImplOpenGL2_Data)();
io.BackendRendererUserData = (void*)bd;
io.BackendRendererName = "imgui_impl_opengl2";
io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports; // We can create multi-viewports on the Renderer side (optional)
io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports; // We can create multi-viewports on the Renderer side (optional)
io.BackendFlags |= ImGuiBackendFlags_RendererHasTextures; // We can honor ImGuiPlatformIO::Textures[] requests during render.
ImGui_ImplOpenGL2_InitMultiViewportSupport();
@ -127,7 +127,7 @@ void ImGui_ImplOpenGL2_Shutdown()
ImGui_ImplOpenGL2_DestroyDeviceObjects();
io.BackendRendererName = nullptr;
io.BackendRendererUserData = nullptr;
io.BackendFlags &= ~ImGuiBackendFlags_RendererHasViewports;
io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasTextures | ImGuiBackendFlags_RendererHasViewports);
IM_DELETE(bd);
}
@ -135,11 +135,7 @@ void ImGui_ImplOpenGL2_NewFrame()
{
ImGui_ImplOpenGL2_Data* bd = ImGui_ImplOpenGL2_GetBackendData();
IM_ASSERT(bd != nullptr && "Context or backend not initialized! Did you call ImGui_ImplOpenGL2_Init()?");
if (!bd->FontTexture)
ImGui_ImplOpenGL2_CreateDeviceObjects();
if (!bd->FontTexture)
ImGui_ImplOpenGL2_CreateFontsTexture();
IM_UNUSED(bd);
}
static void ImGui_ImplOpenGL2_SetupRenderState(ImDrawData* draw_data, int fb_width, int fb_height)
@ -197,6 +193,11 @@ void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
if (fb_width == 0 || fb_height == 0)
return;
// Catch up with texture updates. Most of the times, the list will have 1 element will an OK status, aka nothing to do.
for (ImTextureData* tex : ImGui::GetPlatformIO().Textures)
if (tex->Status != ImTextureStatus_OK)
ImGui_ImplOpenGL2_UpdateTexture(tex);
// Backup GL state
GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
@ -270,60 +271,79 @@ void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, last_tex_env_mode);
}
bool ImGui_ImplOpenGL2_CreateFontsTexture()
void ImGui_ImplOpenGL2_UpdateTexture(ImTextureData* tex)
{
// Build texture atlas
ImGuiIO& io = ImGui::GetIO();
ImGui_ImplOpenGL2_Data* bd = ImGui_ImplOpenGL2_GetBackendData();
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
// (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
GLint last_texture;
glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
glGenTextures(1, &bd->FontTexture);
glBindTexture(GL_TEXTURE_2D, bd->FontTexture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
// Store our identifier
io.Fonts->SetTexID((ImTextureID)(intptr_t)bd->FontTexture);
// Restore state
glBindTexture(GL_TEXTURE_2D, last_texture);
return true;
}
void ImGui_ImplOpenGL2_DestroyFontsTexture()
{
ImGuiIO& io = ImGui::GetIO();
ImGui_ImplOpenGL2_Data* bd = ImGui_ImplOpenGL2_GetBackendData();
if (bd->FontTexture)
if (tex->Status == ImTextureStatus_WantCreate)
{
glDeleteTextures(1, &bd->FontTexture);
io.Fonts->SetTexID(0);
bd->FontTexture = 0;
// Create and upload new texture to graphics system
//IMGUI_DEBUG_LOG("UpdateTexture #%03d: WantCreate %dx%d\n", tex->UniqueID, tex->Width, tex->Height);
IM_ASSERT(tex->TexID == 0 && tex->BackendUserData == nullptr);
IM_ASSERT(tex->Format == ImTextureFormat_RGBA32);
const void* pixels = tex->GetPixels();
GLuint gl_texture_id = 0;
// Upload texture to graphics system
// (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
GLint last_texture;
GL_CALL(glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture));
GL_CALL(glGenTextures(1, &gl_texture_id));
GL_CALL(glBindTexture(GL_TEXTURE_2D, gl_texture_id));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP));
GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, 0));
GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, tex->Width, tex->Height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels));
// Store identifiers
tex->SetTexID((ImTextureID)(intptr_t)gl_texture_id);
tex->Status = ImTextureStatus_OK;
// Restore state
GL_CALL(glBindTexture(GL_TEXTURE_2D, last_texture));
}
else if (tex->Status == ImTextureStatus_WantUpdates)
{
// Update selected blocks. We only ever write to textures regions which have never been used before!
// This backend choose to use tex->Updates[] but you can use tex->UpdateRect to upload a single region.
GLint last_texture;
GL_CALL(glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture));
GLuint gl_tex_id = (GLuint)(intptr_t)tex->TexID;
GL_CALL(glBindTexture(GL_TEXTURE_2D, gl_tex_id));
GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, tex->Width));
for (ImTextureRect& r : tex->Updates)
GL_CALL(glTexSubImage2D(GL_TEXTURE_2D, 0, r.x, r.y, r.w, r.h, GL_RGBA, GL_UNSIGNED_BYTE, tex->GetPixelsAt(r.x, r.y)));
GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, 0));
tex->Status = ImTextureStatus_OK;
GL_CALL(glBindTexture(GL_TEXTURE_2D, last_texture)); // Restore state
}
else if (tex->Status == ImTextureStatus_WantDestroy)
{
GLuint gl_tex_id = (GLuint)(intptr_t)tex->TexID;
glDeleteTextures(1, &gl_tex_id);
// Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
tex->SetTexID(ImTextureID_Invalid);
tex->Status = ImTextureStatus_Destroyed;
}
}
bool ImGui_ImplOpenGL2_CreateDeviceObjects()
{
return ImGui_ImplOpenGL2_CreateFontsTexture();
return true;
}
void ImGui_ImplOpenGL2_DestroyDeviceObjects()
{
ImGui_ImplOpenGL2_DestroyFontsTexture();
for (ImTextureData* tex : ImGui::GetPlatformIO().Textures)
if (tex->RefCount == 1)
{
tex->Status = ImTextureStatus_WantDestroy;
ImGui_ImplOpenGL2_UpdateTexture(tex);
}
}
//--------------------------------------------------------------------------------------------------------
// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.

8
backends/imgui_impl_opengl2.h
View file

@ -2,7 +2,8 @@
// This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..)
// Implemented features:
// [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
// [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture as texture identifier. Read the FAQ about ImTextureID/ImTextureRef!
// [X] Renderer: Texture updates support for dynamic font system (ImGuiBackendFlags_RendererHasTextures).
// [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
// Missing features or Issues:
// [ ] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
@ -34,9 +35,10 @@ IMGUI_IMPL_API void ImGui_ImplOpenGL2_NewFrame();
IMGUI_IMPL_API void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data);
// Called by Init/NewFrame/Shutdown
IMGUI_IMPL_API bool ImGui_ImplOpenGL2_CreateFontsTexture();
IMGUI_IMPL_API void ImGui_ImplOpenGL2_DestroyFontsTexture();
IMGUI_IMPL_API bool ImGui_ImplOpenGL2_CreateDeviceObjects();
IMGUI_IMPL_API void ImGui_ImplOpenGL2_DestroyDeviceObjects();
// (Advanced) Use e.g. if you want to start updating textures after ImGui::Render() without waiting for the RenderDrawData call.
IMGUI_IMPL_API void ImGui_ImplOpenGL2_UpdateTexture(ImTextureData* tex);
#endif // #ifndef IMGUI_DISABLE