Backends: OpenGL: Add ability to #define IMGUI_IMPL_OPENGL_DEBUG. (#4468, #4825, #4832, #5127, #5655, #5709)

# Conflicts:
#	backends/imgui_impl_opengl3.cpp

backends/imgui_impl_opengl3.cpp

@@ -16,6 +16,7 @@
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2022-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2022-09-27: OpenGL: Added ability to '#define IMGUI_IMPL_OPENGL_DEBUG'.
 //  2022-05-23: OpenGL: Reworking 2021-12-15 "Using buffer orphaning" so it only happens on Intel GPU, seems to cause problems otherwise. (#4468, #4825, #4832, #5127).
 //  2022-05-13: OpenGL: Fix state corruption on OpenGL ES 2.0 due to not preserving GL_ELEMENT_ARRAY_BUFFER_BINDING and vertex attribute states.
 //  2021-12-15: OpenGL: Using buffer orphaning + glBufferSubData(), seems to fix leaks with multi-viewports with some Intel HD drivers.
@@ -180,6 +181,15 @@
 #define IMGUI_IMPL_OPENGL_MAY_HAVE_EXTENSIONS
 #endif
 
+// [Debugging]
+//#define IMGUI_IMPL_OPENGL_DEBUG
+#ifdef IMGUI_IMPL_OPENGL_DEBUG
+#include <stdio.h>
+#define GL_CALL(_CALL)      do { _CALL; GLenum gl_err = glGetError(); if (gl_err != 0) fprintf(stderr, "GL error 0x%x returned from '%s'.\n", gl_err, #_CALL); } while (0)  // Call with error check
+#else
+#define GL_CALL(_CALL)      _CALL   // Call without error check
+#endif
+
 // OpenGL Data
 struct ImGui_ImplOpenGL3_Data
 {
@@ -276,11 +286,14 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
         if (strncmp(vendor, "Intel", 5) == 0)
             bd->UseBufferSubData = true;
 #endif
-    //printf("GL_MAJOR_VERSION = %d\nGL_MINOR_VERSION = %d\nGL_VENDOR = '%s'\nGL_RENDERER = '%s'\n", major, minor, (const char*)glGetString(GL_VENDOR), (const char*)glGetString(GL_RENDERER)); // [DEBUG]
 #else
     bd->GlVersion = 200; // GLES 2
 #endif
 
+#ifdef IMGUI_IMPL_OPENGL_DEBUG
+    printf("GL_MAJOR_VERSION = %d\nGL_MINOR_VERSION = %d\nGL_VENDOR = '%s'\nGL_RENDERER = '%s'\n", major, minor, (const char*)glGetString(GL_VENDOR), (const char*)glGetString(GL_RENDERER)); // [DEBUG]
+#endif
+
 #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
     if (bd->GlVersion >= 320)
         io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
@@ -384,7 +397,7 @@ static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_wid
 
     // Setup viewport, orthographic projection matrix
     // Our visible imgui space lies from draw_data->DisplayPos (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayPos is (0,0) for single viewport apps.
-    glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height);
+    GL_CALL(glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height));
     float L = draw_data->DisplayPos.x;
     float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
     float T = draw_data->DisplayPos.y;
@@ -414,14 +427,14 @@ static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_wid
 #endif
 
     // Bind vertex/index buffers and setup attributes for ImDrawVert
-    glBindBuffer(GL_ARRAY_BUFFER, bd->VboHandle);
-    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bd->ElementsHandle);
-    glEnableVertexAttribArray(bd->AttribLocationVtxPos);
-    glEnableVertexAttribArray(bd->AttribLocationVtxUV);
-    glEnableVertexAttribArray(bd->AttribLocationVtxColor);
-    glVertexAttribPointer(bd->AttribLocationVtxPos,   2, GL_FLOAT,         GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos));
-    glVertexAttribPointer(bd->AttribLocationVtxUV,    2, GL_FLOAT,         GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv));
-    glVertexAttribPointer(bd->AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE,  sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col));
+    GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, bd->VboHandle));
+    GL_CALL(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bd->ElementsHandle));
+    GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxPos));
+    GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxUV));
+    GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxColor));
+    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxPos,   2, GL_FLOAT,         GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos)));
+    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxUV,    2, GL_FLOAT,         GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv)));
+    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col)));
 }
 
 // OpenGL3 Render function.
@@ -481,7 +494,7 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
     // The renderer would actually work without any VAO bound, but then our VertexAttrib calls would overwrite the default one currently bound.
     GLuint vertex_array_object = 0;
 #ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
-    glGenVertexArrays(1, &vertex_array_object);
+    GL_CALL(glGenVertexArrays(1, &vertex_array_object));
 #endif
     ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
 
@@ -505,20 +518,20 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
             if (bd->VertexBufferSize < vtx_buffer_size)
             {
                 bd->VertexBufferSize = vtx_buffer_size;
-                glBufferData(GL_ARRAY_BUFFER, bd->VertexBufferSize, NULL, GL_STREAM_DRAW);
+                GL_CALL(glBufferData(GL_ARRAY_BUFFER, bd->VertexBufferSize, NULL, GL_STREAM_DRAW));
             }
             if (bd->IndexBufferSize < idx_buffer_size)
             {
                 bd->IndexBufferSize = idx_buffer_size;
-                glBufferData(GL_ELEMENT_ARRAY_BUFFER, bd->IndexBufferSize, NULL, GL_STREAM_DRAW);
+                GL_CALL(glBufferData(GL_ELEMENT_ARRAY_BUFFER, bd->IndexBufferSize, NULL, GL_STREAM_DRAW));
             }
-            glBufferSubData(GL_ARRAY_BUFFER, 0, vtx_buffer_size, (const GLvoid*)cmd_list->VtxBuffer.Data);
-            glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, idx_buffer_size, (const GLvoid*)cmd_list->IdxBuffer.Data);
+            GL_CALL(glBufferSubData(GL_ARRAY_BUFFER, 0, vtx_buffer_size, (const GLvoid*)cmd_list->VtxBuffer.Data));
+            GL_CALL(glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, idx_buffer_size, (const GLvoid*)cmd_list->IdxBuffer.Data));
         }
         else
         {
-            glBufferData(GL_ARRAY_BUFFER, vtx_buffer_size, (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW);
-            glBufferData(GL_ELEMENT_ARRAY_BUFFER, idx_buffer_size, (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW);
+            GL_CALL(glBufferData(GL_ARRAY_BUFFER, vtx_buffer_size, (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW));
+            GL_CALL(glBufferData(GL_ELEMENT_ARRAY_BUFFER, idx_buffer_size, (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW));
         }
 
         for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
@@ -542,23 +555,23 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
                     continue;
 
                 // Apply scissor/clipping rectangle (Y is inverted in OpenGL)
-                glScissor((int)clip_min.x, (int)((float)fb_height - clip_max.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y));
+                GL_CALL(glScissor((int)clip_min.x, (int)((float)fb_height - clip_max.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y)));
 
                 // Bind texture, Draw
-                glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->GetTexID());
+                GL_CALL(glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->GetTexID()));
 #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
                 if (bd->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);
+                    GL_CALL(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
-                glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx)));
+                GL_CALL(glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx))));
             }
         }
     }
 
     // Destroy the temporary VAO
 #ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
-    glDeleteVertexArrays(1, &vertex_array_object);
+    GL_CALL(glDeleteVertexArrays(1, &vertex_array_object));
 #endif
 
     // Restore modified GL state
@@ -611,21 +624,21 @@ bool ImGui_ImplOpenGL3_CreateFontsTexture()
     // 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);
+    GL_CALL(glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture));
+    GL_CALL(glGenTextures(1, &bd->FontTexture));
+    GL_CALL(glBindTexture(GL_TEXTURE_2D, bd->FontTexture));
+    GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
+    GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
 #ifdef GL_UNPACK_ROW_LENGTH // Not on WebGL/ES
-    glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
+    GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, 0));
 #endif
-    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
+    GL_CALL(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);
+    GL_CALL(glBindTexture(GL_TEXTURE_2D, last_texture));
 
     return true;
 }