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Backends: OpenGL3: WIP testing alternate way to run buffer updates. (#…
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ocornut committed Dec 15, 2021
1 parent 48f2633 commit 721a4e4
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Showing 4 changed files with 25 additions and 3 deletions.
19 changes: 17 additions & 2 deletions backends/imgui_impl_opengl3.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@

// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2021-12-15: OpenGL: Using buffer orphaning + glBufferSubData(), seems to fix leaks with multi-viewports with some Intel HD drivers.
// 2021-08-23: OpenGL: Fixed ES 3.0 shader ("#version 300 es") use normal precision floats to avoid wobbly rendering at HD resolutions.
// 2021-08-19: OpenGL: Embed and use our own minimal GL loader (imgui_impl_opengl3_loader.h), removing requirement and support for third-party loader.
// 2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
Expand Down Expand Up @@ -174,6 +175,8 @@ struct ImGui_ImplOpenGL3_Data
GLuint AttribLocationVtxUV;
GLuint AttribLocationVtxColor;
unsigned int VboHandle, ElementsHandle;
GLsizeiptr VertexBufferSize;
GLsizeiptr IndexBufferSize;
bool HasClipOrigin;

ImGui_ImplOpenGL3_Data() { memset(this, 0, sizeof(*this)); }
Expand Down Expand Up @@ -425,8 +428,20 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
const ImDrawList* cmd_list = draw_data->CmdLists[n];

// Upload vertex/index buffers
glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)cmd_list->VtxBuffer.Size * (int)sizeof(ImDrawVert), (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, (GLsizeiptr)cmd_list->IdxBuffer.Size * (int)sizeof(ImDrawIdx), (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW);
GLsizeiptr vtx_buffer_size = (GLsizeiptr)cmd_list->VtxBuffer.Size * (int)sizeof(ImDrawVert);
GLsizeiptr idx_buffer_size = (GLsizeiptr)cmd_list->IdxBuffer.Size * (int)sizeof(ImDrawIdx);
if (bd->VertexBufferSize < vtx_buffer_size)
{
bd->VertexBufferSize = vtx_buffer_size;
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);
}
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);

for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
{
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5 changes: 5 additions & 0 deletions backends/imgui_impl_opengl3_loader.h
Original file line number Diff line number Diff line change
Expand Up @@ -249,11 +249,13 @@ typedef void (APIENTRYP PFNGLBINDBUFFERPROC) (GLenum target, GLuint buffer);
typedef void (APIENTRYP PFNGLDELETEBUFFERSPROC) (GLsizei n, const GLuint *buffers);
typedef void (APIENTRYP PFNGLGENBUFFERSPROC) (GLsizei n, GLuint *buffers);
typedef void (APIENTRYP PFNGLBUFFERDATAPROC) (GLenum target, GLsizeiptr size, const void *data, GLenum usage);
typedef void (APIENTRYP PFNGLBUFFERSUBDATAPROC) (GLenum target, GLintptr offset, GLsizeiptr size, const void *data);
#ifdef GL_GLEXT_PROTOTYPES
GLAPI void APIENTRY glBindBuffer (GLenum target, GLuint buffer);
GLAPI void APIENTRY glDeleteBuffers (GLsizei n, const GLuint *buffers);
GLAPI void APIENTRY glGenBuffers (GLsizei n, GLuint *buffers);
GLAPI void APIENTRY glBufferData (GLenum target, GLsizeiptr size, const void *data, GLenum usage);
GLAPI void APIENTRY glBufferSubData (GLenum target, GLintptr offset, GLsizeiptr size, const void *data);
#endif
#endif /* GL_VERSION_1_5 */
#ifndef GL_VERSION_2_0
Expand Down Expand Up @@ -447,6 +449,7 @@ union GL3WProcs {
PFNGLBLENDEQUATIONSEPARATEPROC BlendEquationSeparate;
PFNGLBLENDFUNCSEPARATEPROC BlendFuncSeparate;
PFNGLBUFFERDATAPROC BufferData;
PFNGLBUFFERSUBDATAPROC BufferSubData;
PFNGLCLEARPROC Clear;
PFNGLCLEARCOLORPROC ClearColor;
PFNGLCOMPILESHADERPROC CompileShader;
Expand Down Expand Up @@ -506,6 +509,7 @@ GL3W_API extern union GL3WProcs imgl3wProcs;
#define glBlendEquationSeparate imgl3wProcs.gl.BlendEquationSeparate
#define glBlendFuncSeparate imgl3wProcs.gl.BlendFuncSeparate
#define glBufferData imgl3wProcs.gl.BufferData
#define glBufferSubData imgl3wProcs.gl.BufferSubData
#define glClear imgl3wProcs.gl.Clear
#define glClearColor imgl3wProcs.gl.ClearColor
#define glCompileShader imgl3wProcs.gl.CompileShader
Expand Down Expand Up @@ -692,6 +696,7 @@ static const char *proc_names[] = {
"glBlendEquationSeparate",
"glBlendFuncSeparate",
"glBufferData",
"glBufferSubData",
"glClear",
"glClearColor",
"glCompileShader",
Expand Down
2 changes: 2 additions & 0 deletions docs/CHANGELOG.txt
Original file line number Diff line number Diff line change
Expand Up @@ -105,6 +105,8 @@ Other Changes:
- Backends: Vulkan: Call vkCmdSetScissor() at the end of render with a full-viewport to reduce
likehood of issues with people using VK_DYNAMIC_STATE_SCISSOR in their app without calling
vkCmdSetScissor() explicitly every frame. (#4644)
- Backends: OpenGL3: Using buffer orphaning + glBufferSubData(), seems to fix leaks with multi-viewports
with some Intel HD drivers, and perhaps improve performances. (#4468, #4504, #2981, #3381) [@parbo]
- Backends: OpenGL2, Allegro5, Marmalade: Fixed mishandling of the ImDrawCmd::IdxOffset field.
This is an old bug, but due to the way we created drawlists, it never had any visible side-effect before.
The new code for handling Modal and CTRL+Tab dimming/whitening recently made the bug surface. (#4790)
Expand Down
2 changes: 1 addition & 1 deletion imgui_widgets.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -6882,7 +6882,7 @@ static bool IsRootOfOpenMenuSet()
// Instead we don't treat Popup specifically (in order to consistently support menu features in them), maybe the first child menu of a Popup
// doesn't have the _ChildWindow flag, and we rely on this IsRootOfOpenMenuSet() check to allow hovering between root window/popup and first chilld menu.
const ImGuiPopupData* upper_popup = &g.OpenPopupStack[g.BeginPopupStack.Size];
return (upper_popup && /*upper_popup->OpenParentId == window->IDStack.back() &&*/ upper_popup->Window && (upper_popup->Window->Flags & ImGuiWindowFlags_ChildMenu));
return (/*upper_popup->OpenParentId == window->IDStack.back() &&*/ upper_popup->Window && (upper_popup->Window->Flags & ImGuiWindowFlags_ChildMenu));
}

bool ImGui::BeginMenuEx(const char* label, const char* icon, bool enabled)
Expand Down

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