Backends: OpenGL3: Backup/restore GL_PRIMITIVE_RESTART state (#3544)
diff --git a/backends/imgui_impl_opengl3.cpp b/backends/imgui_impl_opengl3.cpp
index aa0e9e5..a26538d 100644
--- a/backends/imgui_impl_opengl3.cpp
+++ b/backends/imgui_impl_opengl3.cpp
@@ -13,6 +13,7 @@
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
+// 2020-10-23: OpenGL: Save and restore current GL_PRIMITIVE_RESTART state.
// 2020-10-15: OpenGL: Use glGetString(GL_VERSION) instead of glGetIntegerv(GL_MAJOR_VERSION, ...) when the later returns zero (e.g. Desktop GL 2.x)
// 2020-09-17: OpenGL: Fix to avoid compiling/calling glBindSampler() on ES or pre 3.3 context which have the defines set by a loader.
// 2020-07-10: OpenGL: Added support for glad2 OpenGL loader.
@@ -134,6 +135,11 @@
#define IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
#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
+#endif
+
// OpenGL Data
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.
@@ -244,6 +250,10 @@
glDisable(GL_CULL_FACE);
glDisable(GL_DEPTH_TEST);
glEnable(GL_SCISSOR_TEST);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
+ if (g_GlVersion >= 310)
+ glDisable(GL_PRIMITIVE_RESTART);
+#endif
#ifdef GL_POLYGON_MODE
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
#endif
@@ -334,6 +344,9 @@
GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE);
GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST);
GLboolean last_enable_scissor_test = glIsEnabled(GL_SCISSOR_TEST);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
+ GLboolean last_enable_primitive_restart = g_GlVersion >= 310 ? glIsEnabled(GL_PRIMITIVE_RESTART) : GL_FALSE;
+#endif
// Setup desired GL state
// Recreate the VAO every time (this is to easily allow multiple GL contexts to be rendered to. VAO are not shared among GL contexts)
@@ -419,6 +432,11 @@
if (last_enable_cull_face) glEnable(GL_CULL_FACE); else glDisable(GL_CULL_FACE);
if (last_enable_depth_test) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST);
if (last_enable_scissor_test) glEnable(GL_SCISSOR_TEST); else glDisable(GL_SCISSOR_TEST);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
+ if (g_GlVersion >= 310)
+ if (last_enable_primitive_restart) glEnable(GL_PRIMITIVE_RESTART); else glDisable(GL_PRIMITIVE_RESTART);
+#endif
+
#ifdef GL_POLYGON_MODE
glPolygonMode(GL_FRONT_AND_BACK, (GLenum)last_polygon_mode[0]);
#endif
diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
index 68e3050..bd70928 100644
--- a/docs/CHANGELOG.txt
+++ b/docs/CHANGELOG.txt
@@ -59,8 +59,9 @@
- Tab Bar: Do not display a tooltip if the name already fits over a given tab. (#3521)
- Drag and Drop: Fix drag and drop to tie same-size drop targets by choosen the later one. Fixes dragging
into a full-window-sized dockspace inside a zero-padded window. (#3519, #2717) [@Black-Cat]
-- Backends: OpenGL: use glGetString(GL_VERSION) query instead of glGetIntegerv(GL_MAJOR_VERSION, ...)
+- Backends: OpenGL3: Use glGetString(GL_VERSION) query instead of glGetIntegerv(GL_MAJOR_VERSION, ...)
when the later returns zero (e.g. Desktop GL 2.x). (#3530) [@xndcn]
+- Backends: OpenGL3: Backup and restore GL_PRIMITIVE_RESTART state. (#3544) [@Xipiryon]
- Docs: Split examples/README.txt into docs/BACKENDS.md and docs/EXAMPLES.md improved them.
- Docs: Consistently renamed all occurences of "binding" and "back-end" to "backend" in comments and docs.
