From f002a1189888faa0f98cfde963deeb78f02f4b43 Mon Sep 17 00:00:00 2001 From: omar Date: Fri, 25 Oct 2019 11:56:36 +0200 Subject: [PATCH] Backends: OpenGL3: Fix building with pre-3.2 GL bindings which do not expose glDrawElementsBaseVertex(), using runtime GL version to decide if we set ImGuiBackendFlags_RendererHasVtxOffset. (#2866, #2852) [@dpilawa] --- docs/CHANGELOG.txt | 2 ++ examples/imgui_impl_opengl3.cpp | 34 ++++++++++++++++----------------- 2 files changed, 19 insertions(+), 17 deletions(-) diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt index d52561d69..72c7c18a7 100644 --- a/docs/CHANGELOG.txt +++ b/docs/CHANGELOG.txt @@ -73,6 +73,8 @@ Other Changes: - Demo: Added simple item reordering demo in Widgets -> Drag and Drop section. (#2823, #143) [@rokups] - Examples: DX12: Using IDXGIDebug1::ReportLiveObjects() when DX12_ENABLE_DEBUG_LAYER is enabled. - Examples: Emscripten: Removed NO_FILESYSTEM from Makefile, seems to fail on some setup. (#2734) [@Funto] +- Backends: OpenGL3: Fix building with pre-3.2 GL loaders which do not expose glDrawElementsBaseVertex(), + using runtime GL version to decide if we set ImGuiBackendFlags_RendererHasVtxOffset. (#2866, #2852) [@dpilawa] - Backends: OSX: Fix using Backspace key. (#2578, #2817, #2818) [@DiligentGraphics] - Backends: GLFW: Previously installed user callbacks are now restored on shutdown. (#2836) [@malte-v] - CI: Set up a bunch of continuous-integration tests using GitHub Actions. We now compile many of the example diff --git a/examples/imgui_impl_opengl3.cpp b/examples/imgui_impl_opengl3.cpp index 7f2c588e3..c1d44da6b 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) +// 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. // 2019-09-22: OpenGL: Detect default GL loader using __has_include compiler facility. // 2019-09-16: OpenGL: Tweak initialization code to allow application calling ImGui_ImplOpenGL3_CreateFontsTexture() before the first NewFrame() call. // 2019-05-29: OpenGL: Desktop GL only: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag. @@ -77,7 +78,7 @@ #include "TargetConditionals.h" #endif -// Auto-detect GL version +// Auto-enable GLES on matching platforms #if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) #if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV)) || (defined(__ANDROID__)) #define IMGUI_IMPL_OPENGL_ES3 // iOS, Android -> GL ES 3, "#version 300 es" @@ -99,9 +100,9 @@ #include #elif defined(IMGUI_IMPL_OPENGL_ES3) #if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV)) -#include // Use GL ES 3 +#include // Use GL ES 3 #else -#include // Use GL ES 3 +#include // Use GL ES 3 #endif #else // About Desktop OpenGL function loaders: @@ -119,16 +120,16 @@ #endif #endif -// Desktop GL has glDrawElementsBaseVertex() which GL ES and WebGL don't have. +// 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_DRAW_WITH_BASE_VERTEX 0 +#define IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET 0 #else -#define IMGUI_IMPL_OPENGL_MAY_HAVE_DRAW_WITH_BASE_VERTEX 1 +#define IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET 1 #endif // OpenGL Data -static char g_GlslVersionString[32] = ""; -static GLuint g_GlVersion = 0; +static GLuint g_GlVersion = 0; // Extracted at runtime using GL_MAJOR_VERSION, GL_MINOR_VERSION queries. +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; static int g_AttribLocationTex = 0, g_AttribLocationProjMtx = 0; // Uniforms location @@ -138,11 +139,11 @@ static unsigned int g_VboHandle = 0, g_ElementsHandle = 0; // Functions bool ImGui_ImplOpenGL3_Init(const char* glsl_version) { - // query for GL version + // Query for GL version #if !defined(IMGUI_IMPL_OPENGL_ES2) GLint major, minor; - glGetIntegerv (GL_MAJOR_VERSION, &major); - glGetIntegerv (GL_MINOR_VERSION, &minor); + glGetIntegerv(GL_MAJOR_VERSION, &major); + glGetIntegerv(GL_MINOR_VERSION, &minor); g_GlVersion = major * 1000 + minor; #else g_GlVersion = 2000; // GLES 2 @@ -151,12 +152,13 @@ bool ImGui_ImplOpenGL3_Init(const char* glsl_version) // Setup back-end capabilities flags ImGuiIO& io = ImGui::GetIO(); io.BackendRendererName = "imgui_impl_opengl3"; -#if IMGUI_IMPL_OPENGL_MAY_HAVE_DRAW_WITH_BASE_VERTEX +#if IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET if (g_GlVersion >= 3200) io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset; // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes. #endif - // Store GLSL version string so we can refer to it later in case we recreate shaders. Note: GLSL version is NOT the same as GL version. Leave this to NULL if unsure. + // Store GLSL version string so we can refer to it later in case we recreate shaders. + // Note: GLSL version is NOT the same as GL version. Leave this to NULL if unsure. #if defined(IMGUI_IMPL_OPENGL_ES2) if (glsl_version == NULL) glsl_version = "#version 100"; @@ -356,14 +358,12 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data) // Bind texture, Draw glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId); -#if IMGUI_IMPL_OPENGL_MAY_HAVE_DRAW_WITH_BASE_VERTEX +#if IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET if (g_GlVersion >= 3200) 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 - glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx))); -#else - glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx))); #endif + glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx))); } } }