Backends: OpenGL3: Fixed version check mistakenly testing for GL 4.0+ instead of 3.2+ to enable ImGuiBackendFlags_RendererHasVtxOffset, leaving 3.2 contexts without it. (#3119, #2866, #2852)
diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
index 43c70d3..14f5c62 100644
--- a/docs/CHANGELOG.txt
+++ b/docs/CHANGELOG.txt
@@ -84,6 +84,8 @@
- CI: Added more tests on the continuous-integration server: extra warnings for Clang/GCC, building
SDL+Metal example, building imgui_freetype.cpp, more compile-time imconfig.h settings: disabling
obsolete functions, enabling 32-bit ImDrawIdx, enabling 32-bit ImWchar, disabling demo. [@rokups]
+- Backends: OpenGL3: Fixed version check mistakenly testing for GL 4.0+ instead of 3.2+ to enable
+ ImGuiBackendFlags_RendererHasVtxOffset, leaving 3.2 contexts without it. (#3119, #2866) [@wolfpld]
- Backends: OpenGL3: Added include support for older glbinding 2.x loader. (#3061) [@DonKult]
- Backends: Win32: Added ImGui_ImplWin32_EnableDpiAwareness(), ImGui_ImplWin32_GetDpiScaleForHwnd(),
ImGui_ImplWin32_GetDpiScaleForMonitor() helpers functions (backported from the docking branch).
diff --git a/examples/imgui_impl_opengl3.cpp b/examples/imgui_impl_opengl3.cpp
index 2f908f4..40e531d 100644
--- a/examples/imgui_impl_opengl3.cpp
+++ b/examples/imgui_impl_opengl3.cpp
@@ -13,6 +13,7 @@
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
+// 2020-04-12: OpenGL: Fixed context version check mistakenly testing for 4.0+ instead of 3.2+ to enable ImGuiBackendFlags_RendererHasVtxOffset.
// 2020-03-24: OpenGL: Added support for glbinding 2.x OpenGL loader.
// 2020-01-07: OpenGL: Added support for glbinding 3.x OpenGL loader.
// 2019-10-25: OpenGL: Using a combination of GL define and runtime GL version to decide whether to use glDrawElementsBaseVertex(). Fix building with pre-3.2 GL loaders.
@@ -141,7 +142,7 @@
#endif
// OpenGL Data
-static GLuint g_GlVersion = 0; // Extracted at runtime using GL_MAJOR_VERSION, GL_MINOR_VERSION queries.
+static GLuint g_GlVersion = 0; // Extracted at runtime using GL_MAJOR_VERSION, GL_MINOR_VERSION queries (e.g. 320 for GL 3.2)
static char g_GlslVersionString[32] = ""; // Specified by user or detected based on compile time GL settings.
static GLuint g_FontTexture = 0;
static GLuint g_ShaderHandle = 0, g_VertHandle = 0, g_FragHandle = 0;
@@ -152,21 +153,21 @@
// Functions
bool ImGui_ImplOpenGL3_Init(const char* glsl_version)
{
- // Query for GL version
+ // Query for GL version (e.g. 320 for GL 3.2)
#if !defined(IMGUI_IMPL_OPENGL_ES2)
GLint major, minor;
glGetIntegerv(GL_MAJOR_VERSION, &major);
glGetIntegerv(GL_MINOR_VERSION, &minor);
- g_GlVersion = major * 1000 + minor;
+ g_GlVersion = major * 100 + minor * 10;
#else
- g_GlVersion = 2000; // GLES 2
+ g_GlVersion = 200; // GLES 2
#endif
// Setup back-end capabilities flags
ImGuiIO& io = ImGui::GetIO();
io.BackendRendererName = "imgui_impl_opengl3";
#if IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
- if (g_GlVersion >= 3200)
+ if (g_GlVersion >= 320)
io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset; // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
#endif
@@ -378,7 +379,7 @@
// Bind texture, Draw
glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
#if IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
- if (g_GlVersion >= 3200)
+ if (g_GlVersion >= 320)
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);
else
#endif
