From 528b12eb7a30ba264ddcb4e33860e403bd133623 Mon Sep 17 00:00:00 2001 From: u3shit Date: Tue, 21 Apr 2020 02:13:06 +0200 Subject: [PATCH] Fix glClipControl(GL_UPPER_LEFT) handling in opengl3. --- docs/CHANGELOG.txt | 2 ++ examples/imgui_impl_opengl3.cpp | 21 +++++++++++---------- 2 files changed, 13 insertions(+), 10 deletions(-) diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt index 81cb3bab..18cb9659 100644 --- a/docs/CHANGELOG.txt +++ b/docs/CHANGELOG.txt @@ -44,6 +44,8 @@ Other Changes: - TreeNode: Fixed bug where dragging a payload over a TreeNode() with either _OpenOnDoubleClick or _OpenOnArrow would open the node. (#143) - Backends: Win32: Support for #define NOGDI, won't try to call GetDeviceCaps(). (#3137, #2327) +- Backends: OpenGL: Fixed handling of GL 4.5+ glClipControl(GL_UPPER_LEFT) by inverting the + projection matrix top and bottom values. (#3143, #3146) [@u3shit] ----------------------------------------------------------------------- diff --git a/examples/imgui_impl_opengl3.cpp b/examples/imgui_impl_opengl3.cpp index 40e531dd..bf8225d0 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) +// 2020-04-21: OpenGL: Fixed handling of glClipControl(GL_UPPER_LEFT) by inverting projection matrix. // 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. @@ -243,6 +244,14 @@ static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_wid glPolygonMode(GL_FRONT_AND_BACK, GL_FILL); #endif + // Support for GL 4.5 rarely used glClipControl(GL_UPPER_LEFT) + bool clip_origin_lower_left = true; +#if defined(GL_CLIP_ORIGIN) && !defined(__APPLE__) + GLenum current_clip_origin = 0; glGetIntegerv(GL_CLIP_ORIGIN, (GLint*)¤t_clip_origin); + if (current_clip_origin == GL_UPPER_LEFT) + clip_origin_lower_left = false; +#endif + // 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); @@ -250,6 +259,7 @@ static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_wid float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x; float T = draw_data->DisplayPos.y; float B = draw_data->DisplayPos.y + draw_data->DisplaySize.y; + if (!clip_origin_lower_left) { float tmp = T; T = B; B = tmp; } // Swap top and bottom if origin is upper left const float ortho_projection[4][4] = { { 2.0f/(R-L), 0.0f, 0.0f, 0.0f }, @@ -318,12 +328,6 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data) 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); - bool clip_origin_lower_left = true; -#if defined(GL_CLIP_ORIGIN) && !defined(__APPLE__) - GLenum last_clip_origin = 0; glGetIntegerv(GL_CLIP_ORIGIN, (GLint*)&last_clip_origin); // Support for GL 4.5's glClipControl(GL_UPPER_LEFT) - if (last_clip_origin == GL_UPPER_LEFT) - clip_origin_lower_left = 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) @@ -371,10 +375,7 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data) if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f) { // Apply scissor/clipping rectangle - if (clip_origin_lower_left) - glScissor((int)clip_rect.x, (int)(fb_height - clip_rect.w), (int)(clip_rect.z - clip_rect.x), (int)(clip_rect.w - clip_rect.y)); - else - glScissor((int)clip_rect.x, (int)clip_rect.y, (int)clip_rect.z, (int)clip_rect.w); // Support for GL 4.5 rarely used glClipControl(GL_UPPER_LEFT) + glScissor((int)clip_rect.x, (int)(fb_height - clip_rect.w), (int)(clip_rect.z - clip_rect.x), (int)(clip_rect.w - clip_rect.y)); // Bind texture, Draw glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);