From 512d39d03169fdaa5a122eae586ab90577ee9af7 Mon Sep 17 00:00:00 2001 From: omar Date: Fri, 29 Mar 2019 16:17:04 +0100 Subject: [PATCH] Examples: OpenGL3: Minor tweaks, clarifications + not calling glBindBuffer more than necessary in the render loop. --- docs/CHANGELOG.txt | 1 + examples/imgui_impl_allegro5.cpp | 2 +- examples/imgui_impl_opengl3.cpp | 50 +++++++++++++++++--------------- examples/imgui_impl_vulkan.cpp | 3 +- imgui.h | 2 +- 5 files changed, 32 insertions(+), 26 deletions(-) diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt index e1911d3ee..5193b8bfc 100644 --- a/docs/CHANGELOG.txt +++ b/docs/CHANGELOG.txt @@ -43,6 +43,7 @@ Other Changes: - Inputs: Also add support for horizontal scroll with Shift+Mouse Wheel. (#2424, #1463) [@LucaRood] - Examples: OpenGL: Added a dummy GL call + comments in ImGui_ImplOpenGL3_Init() to detect uninitialized GL function loaders early, and help users understand what they are missing. (#2421) +- Examples: OpenGL3: Minor tweaks + not calling glBindBuffer more than necessary in the render loop. - Examples: FreeGLUT: Made io.DeltaTime always > 0. (#2430) diff --git a/examples/imgui_impl_allegro5.cpp b/examples/imgui_impl_allegro5.cpp index ffd59d730..3b589c324 100644 --- a/examples/imgui_impl_allegro5.cpp +++ b/examples/imgui_impl_allegro5.cpp @@ -154,7 +154,7 @@ bool ImGui_ImplAllegro5_CreateDeviceObjects() { // Build texture atlas ImGuiIO &io = ImGui::GetIO(); - unsigned char *pixels; + unsigned char* pixels; int width, height; io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height); diff --git a/examples/imgui_impl_opengl3.cpp b/examples/imgui_impl_opengl3.cpp index 989043633..347da4700 100644 --- a/examples/imgui_impl_opengl3.cpp +++ b/examples/imgui_impl_opengl3.cpp @@ -12,6 +12,7 @@ // CHANGELOG // (minor and older changes stripped away, please see git history for details) +// 2019-03-29: OpenGL: Not calling glBindBuffer more than necessary in the render loop. // 2019-03-15: OpenGL: Added a dummy GL call + comments in ImGui_ImplOpenGL3_Init() to detect uninitialized GL function loaders early. // 2019-03-03: OpenGL: Fix support for ES 2.0 (WebGL 1.0). // 2019-02-20: OpenGL: Fix for OSX not supporting OpenGL 4.5, we don't try to read GL_CLIP_ORIGIN even if defined by the headers/loader. @@ -104,8 +105,8 @@ static char g_GlslVersionString[32] = ""; static GLuint g_FontTexture = 0; static GLuint g_ShaderHandle = 0, g_VertHandle = 0, g_FragHandle = 0; -static int g_AttribLocationTex = 0, g_AttribLocationProjMtx = 0; -static int g_AttribLocationPosition = 0, g_AttribLocationUV = 0, g_AttribLocationColor = 0; +static int g_AttribLocationTex = 0, g_AttribLocationProjMtx = 0; // Uniforms location +static int g_AttribLocationVtxPos = 0, g_AttribLocationVtxUV = 0, g_AttribLocationVtxColor = 0; // Vertex attributes location static unsigned int g_VboHandle = 0, g_ElementsHandle = 0; // Functions @@ -170,7 +171,7 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data) #endif GLint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer); #ifndef IMGUI_IMPL_OPENGL_ES2 - GLint last_vertex_array; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array); + GLint last_vertex_array_object; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array_object); #endif #ifdef GL_POLYGON_MODE GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode); @@ -226,20 +227,23 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data) glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 may set that otherwise. #endif + // Recreate the VAO every time (this is to easily allow multiple GL contexts to be rendered to. VAO are not shared among GL contexts) + // The renderer would actually work without any VAO bound, but then our VertexAttrib calls would overwrite the default one currently bound. #ifndef IMGUI_IMPL_OPENGL_ES2 - // Recreate the VAO every time - // (This is to easily allow multiple GL contexts. VAO are not shared among GL contexts, and we don't track creation/deletion of windows so we don't have an obvious key to use to cache them.) - GLuint vao_handle = 0; - glGenVertexArrays(1, &vao_handle); - glBindVertexArray(vao_handle); + GLuint vertex_array_object = 0; + glGenVertexArrays(1, &vertex_array_object); + glBindVertexArray(vertex_array_object); #endif + + // Bind vertex/index buffers and setup attributes for ImDrawVert glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle); - glEnableVertexAttribArray(g_AttribLocationPosition); - glEnableVertexAttribArray(g_AttribLocationUV); - glEnableVertexAttribArray(g_AttribLocationColor); - glVertexAttribPointer(g_AttribLocationPosition, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos)); - glVertexAttribPointer(g_AttribLocationUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv)); - glVertexAttribPointer(g_AttribLocationColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col)); + glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_ElementsHandle); + glEnableVertexAttribArray(g_AttribLocationVtxPos); + glEnableVertexAttribArray(g_AttribLocationVtxUV); + glEnableVertexAttribArray(g_AttribLocationVtxColor); + glVertexAttribPointer(g_AttribLocationVtxPos, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos)); + glVertexAttribPointer(g_AttribLocationVtxUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv)); + glVertexAttribPointer(g_AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col)); // Will project scissor/clipping rectangles into framebuffer space ImVec2 clip_off = draw_data->DisplayPos; // (0,0) unless using multi-viewports @@ -251,10 +255,8 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data) const ImDrawList* cmd_list = draw_data->CmdLists[n]; size_t idx_buffer_offset = 0; - glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle); + // Upload vertex/index buffers glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)cmd_list->VtxBuffer.Size * sizeof(ImDrawVert), (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW); - - glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_ElementsHandle); glBufferData(GL_ELEMENT_ARRAY_BUFFER, (GLsizeiptr)cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx), (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW); for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++) @@ -280,7 +282,7 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data) 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's glClipControl(GL_UPPER_LEFT) + 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) // Bind texture, Draw glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId); @@ -290,8 +292,10 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data) idx_buffer_offset += pcmd->ElemCount * sizeof(ImDrawIdx); } } + + // Destroy the temporary VAO #ifndef IMGUI_IMPL_OPENGL_ES2 - glDeleteVertexArrays(1, &vao_handle); + glDeleteVertexArrays(1, &vertex_array_object); #endif // Restore modified GL state @@ -302,7 +306,7 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data) #endif glActiveTexture(last_active_texture); #ifndef IMGUI_IMPL_OPENGL_ES2 - glBindVertexArray(last_vertex_array); + glBindVertexArray(last_vertex_array_object); #endif glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer); glBlendEquationSeparate(last_blend_equation_rgb, last_blend_equation_alpha); @@ -554,9 +558,9 @@ bool ImGui_ImplOpenGL3_CreateDeviceObjects() g_AttribLocationTex = glGetUniformLocation(g_ShaderHandle, "Texture"); g_AttribLocationProjMtx = glGetUniformLocation(g_ShaderHandle, "ProjMtx"); - g_AttribLocationPosition = glGetAttribLocation(g_ShaderHandle, "Position"); - g_AttribLocationUV = glGetAttribLocation(g_ShaderHandle, "UV"); - g_AttribLocationColor = glGetAttribLocation(g_ShaderHandle, "Color"); + g_AttribLocationVtxPos = glGetAttribLocation(g_ShaderHandle, "Position"); + g_AttribLocationVtxUV = glGetAttribLocation(g_ShaderHandle, "UV"); + g_AttribLocationVtxColor = glGetAttribLocation(g_ShaderHandle, "Color"); // Create buffers glGenBuffers(1, &g_VboHandle); diff --git a/examples/imgui_impl_vulkan.cpp b/examples/imgui_impl_vulkan.cpp index eabc49ea5..77c9408cf 100644 --- a/examples/imgui_impl_vulkan.cpp +++ b/examples/imgui_impl_vulkan.cpp @@ -221,7 +221,7 @@ void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer comm if (!fd->IndexBuffer || fd->IndexBufferSize < index_size) CreateOrResizeBuffer(fd->IndexBuffer, fd->IndexBufferMemory, fd->IndexBufferSize, index_size, VK_BUFFER_USAGE_INDEX_BUFFER_BIT); - // Upload Vertex and index Data: + // Upload vertex/index data into a single contiguous GPU buffer { ImDrawVert* vtx_dst = NULL; ImDrawIdx* idx_dst = NULL; @@ -305,6 +305,7 @@ void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer comm const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i]; if (pcmd->UserCallback) { + // User callback (registered via ImDrawList::AddCallback) pcmd->UserCallback(cmd_list, pcmd); } else diff --git a/imgui.h b/imgui.h index 4c8ab81dd..1d907b049 100644 --- a/imgui.h +++ b/imgui.h @@ -19,7 +19,7 @@ Index of this file: // Misc data structures (ImGuiInputTextCallbackData, ImGuiSizeCallbackData, ImGuiPayload) // Obsolete functions // Helpers (ImGuiOnceUponAFrame, ImGuiTextFilter, ImGuiTextBuffer, ImGuiStorage, ImGuiListClipper, ImColor) -// Draw List API (ImDrawCmd, ImDrawIdx, ImDrawVert, ImDrawChannel, ImDrawListFlags, ImDrawList, ImDrawData) +// Draw List API (ImDrawCallback, ImDrawCmd, ImDrawIdx, ImDrawVert, ImDrawChannel, ImDrawListFlags, ImDrawList, ImDrawData) // Font API (ImFontConfig, ImFontGlyph, ImFontGlyphRangesBuilder, ImFontAtlasFlags, ImFontAtlas, ImFont) */