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Backends: OpenGL2: added ImGuiBackendFlags_RendererHasTextures support.

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Removed ImGui_ImplOpenGL2_CreateFontsTexture() and ImGui_ImplOpenGL2_DestroyFontsTexture().
This commit is contained in:
ocornut
2024-12-18 14:05:55 +01:00
parent dbb91a574f
commit 0430c55b84
2 changed files with 78 additions and 51 deletions
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121
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).
// Missing features or Issues:
// [ ] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
@@ -24,6 +25,7 @@
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2025-06-11: OpenGL: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas. Removed ImGui_ImplOpenGL2_CreateFontsTexture() and ImGui_ImplOpenGL2_DestroyFontsTexture().
// 2024-10-07: OpenGL: Changed default texture sampler to Clamp instead of Repeat/Wrap.
// 2024-06-28: OpenGL: ImGui_ImplOpenGL2_NewFrame() recreates font texture if it has been destroyed by ImGui_ImplOpenGL2_DestroyFontsTexture(). (#7748)
// 2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
@@ -81,8 +83,6 @@
// OpenGL data
struct ImGui_ImplOpenGL2_Data
{
GLuint FontTexture;
ImGui_ImplOpenGL2_Data() { memset((void*)this, 0, sizeof(*this)); }
};
@@ -104,6 +104,7 @@ 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_RendererHasTextures; // We can honor ImGuiPlatformIO::Textures[] requests during render.
return true;
}
@@ -117,6 +118,7 @@ void ImGui_ImplOpenGL2_Shutdown()
ImGui_ImplOpenGL2_DestroyDeviceObjects();
io.BackendRendererName = nullptr;
io.BackendRendererUserData = nullptr;
io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasTextures);
IM_DELETE(bd);
}
@@ -124,11 +126,7 @@ 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)
@@ -186,6 +184,13 @@ 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 with an OK status, aka nothing to do.
// (This almost always points to ImGui::GetPlatformIO().Textures[] but is part of ImDrawData to allow overriding or disabling texture updates).
if (draw_data->Textures != nullptr)
for (ImTextureData* tex : *draw_data->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);
@@ -259,57 +264,77 @@ 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->SetStatus(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));
GL_CALL(glBindTexture(GL_TEXTURE_2D, last_texture)); // Restore state
tex->SetStatus(ImTextureStatus_OK);
}
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->SetStatus(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->SetStatus(ImTextureStatus_WantDestroy);
ImGui_ImplOpenGL2_UpdateTexture(tex);
}
}
//-----------------------------------------------------------------------------

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 atlas (ImGuiBackendFlags_RendererHasTextures).
// Missing features or Issues:
// [ ] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
@@ -33,9 +34,10 @@ 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 need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
IMGUI_IMPL_API void ImGui_ImplOpenGL2_UpdateTexture(ImTextureData* tex);
#endif // #ifndef IMGUI_DISABLE