Backends: OpenGL3: Clarify use of GL_POLYGON_MODE.

backends/imgui_impl_opengl3.cpp

@@ -151,6 +151,11 @@ using namespace gl;
 #define GL_VERTEX_ARRAY_BINDING GL_VERTEX_ARRAY_BINDING_OES
 #endif
 
+// Desktop GL 2.0+ has glPolygonMode() which GL ES and WebGL don't have.
+#ifdef GL_POLYGON_MODE
+#define IMGUI_IMPL_HAS_POLYGON_MODE
+#endif
+
 // Desktop GL 3.2+ has glDrawElementsBaseVertex() which GL ES and WebGL don't have.
 #if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_2)
 #define IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
@@ -330,7 +335,7 @@ static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_wid
     if (bd->GlVersion >= 310)
         glDisable(GL_PRIMITIVE_RESTART);
 #endif
-#ifdef GL_POLYGON_MODE
+#ifdef IMGUI_IMPL_HAS_POLYGON_MODE
     glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
 #endif
 
@@ -412,7 +417,7 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
 #ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
     GLuint last_vertex_array_object; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, (GLint*)&last_vertex_array_object);
 #endif
-#ifdef GL_POLYGON_MODE
+#ifdef IMGUI_IMPL_HAS_POLYGON_MODE
     GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
 #endif
     GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
@@ -521,7 +526,7 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
     if (bd->GlVersion >= 310) { if (last_enable_primitive_restart) glEnable(GL_PRIMITIVE_RESTART); else glDisable(GL_PRIMITIVE_RESTART); }
 #endif
 
-#ifdef GL_POLYGON_MODE
+#ifdef IMGUI_IMPL_HAS_POLYGON_MODE
     glPolygonMode(GL_FRONT_AND_BACK, (GLenum)last_polygon_mode[0]);
 #endif
     glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
@@ -545,7 +550,7 @@ bool ImGui_ImplOpenGL3_CreateFontsTexture()
     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);
-#ifdef GL_UNPACK_ROW_LENGTH
+#ifdef GL_UNPACK_ROW_LENGTH // Not on WebGL/ES
     glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 #endif
     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);

imgui_demo.cpp

@@ -458,7 +458,7 @@ void ImGui::ShowDemoWindow(bool* p_open)
         {
             HelpMarker(
                 "Those flags are set by the backends (imgui_impl_xxx files) to specify their capabilities.\n"
-                "Here we expose then as read-only fields to avoid breaking interactions with your backend.");
+                "Here we expose them as read-only fields to avoid breaking interactions with your backend.");
 
             // Make a local copy to avoid modifying actual backend flags.
             ImGuiBackendFlags backend_flags = io.BackendFlags;