Backends: OpenGL3: Backup and restore GL_PIXEL_UNPACK_BUFFER. (#7253)

Amended with (bd->GlVersion >= 210) checks.

backends/imgui_impl_opengl3.cpp

@@ -191,6 +191,11 @@
 #define IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
 #endif
 
+// Desktop GL and GL ES 3.0+ have glBindBuffer() with GL_PIXEL_UNPACK_BUFFER target.
+#if !defined(IMGUI_IMPL_OPENGL_ES2)
+#define IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_BUFFER_PIXEL_UNPACK
+#endif
+
 // Desktop GL 3.1+ has GL_PRIMITIVE_RESTART state
 #if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_1)
 #define IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
@@ -747,6 +752,10 @@ bool    ImGui_ImplOpenGL3_CreateDeviceObjects()
     GLint last_texture, last_array_buffer;
     glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
     glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_BUFFER_PIXEL_UNPACK
+    GLint last_pixel_unpack_buffer;
+    if (bd->GlVersion >= 210) { glGetIntegerv(GL_PIXEL_UNPACK_BUFFER_BINDING, &last_pixel_unpack_buffer); glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0); }
+#endif
 #ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
     GLint last_vertex_array;
     glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
@@ -920,6 +929,9 @@ bool    ImGui_ImplOpenGL3_CreateDeviceObjects()
     // Restore modified GL state
     glBindTexture(GL_TEXTURE_2D, last_texture);
     glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_BUFFER_PIXEL_UNPACK
+    if (bd->GlVersion >= 210) { glBindBuffer(GL_PIXEL_UNPACK_BUFFER, last_pixel_unpack_buffer); }
+#endif
 #ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
     glBindVertexArray(last_vertex_array);
 #endif

backends/imgui_impl_opengl3_loader.h

@@ -260,6 +260,8 @@ typedef khronos_intptr_t GLintptr;
 #define GL_ARRAY_BUFFER_BINDING           0x8894
 #define GL_ELEMENT_ARRAY_BUFFER_BINDING   0x8895
 #define GL_STREAM_DRAW                    0x88E0
+#define GL_PIXEL_UNPACK_BUFFER            0x88EC
+#define GL_PIXEL_UNPACK_BUFFER_BINDING    0x88EF
 typedef void (APIENTRYP PFNGLBINDBUFFERPROC) (GLenum target, GLuint buffer);
 typedef void (APIENTRYP PFNGLDELETEBUFFERSPROC) (GLsizei n, const GLuint *buffers);
 typedef void (APIENTRYP PFNGLGENBUFFERSPROC) (GLsizei n, GLuint *buffers);

docs/CHANGELOG.txt

@@ -64,6 +64,7 @@ Other changes:
 - Backends: WebGPU: Filling all WGPUDepthStencilState fields explicitly as a recent Dawn
   update stopped setting default values. (#7232) [@GrigoryGraborenko]
 - Backends: WebGPU: Fixed pipeline layout leak. (#7245) [@rajveermalviya]
+- Backends: OpenGL3: Backup and restore GL_PIXEL_UNPACK_BUFFER. (#7253)
 
 
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