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Examples: OpenGL3: Minor tweaks, clarifications + not calling glBindBuffer more than necessary in the render loop.

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omar 2019-03-29 16:17:04 +01:00
parent 9a0e71a6ec
commit 512d39d031
5 changed files with 32 additions and 26 deletions
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1
docs/CHANGELOG.txt
View file

@ -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)

50
examples/imgui_impl_opengl3.cpp
View file

@ -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);

3
examples/imgui_impl_vulkan.cpp
View file

@ -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

2
imgui.h
View file

@ -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)
*/