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Backends: OpenGL: Add ability to #define IMGUI_IMPL_OPENGL_DEBUG. (#4468
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, #4825, #4832, #5127, #5655, #5709)

# Conflicts:
#	backends/imgui_impl_opengl3.cpp
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@ocornut
ocornut committed Sep 27, 2022
1 parent 8f43487 commit 11f5be0
Showing 1 changed file with 43 additions and 30 deletions.
73 changes: 43 additions & 30 deletions backends/imgui_impl_opengl3.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,7 @@
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2022-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
// 2022-09-27: OpenGL: Added ability to '#define IMGUI_IMPL_OPENGL_DEBUG'.
// 2022-05-23: OpenGL: Reworking 2021-12-15 "Using buffer orphaning" so it only happens on Intel GPU, seems to cause problems otherwise. (#4468, #4825, #4832, #5127).
// 2022-05-13: OpenGL: Fix state corruption on OpenGL ES 2.0 due to not preserving GL_ELEMENT_ARRAY_BUFFER_BINDING and vertex attribute states.
// 2021-12-15: OpenGL: Using buffer orphaning + glBufferSubData(), seems to fix leaks with multi-viewports with some Intel HD drivers.
Expand Down Expand Up @@ -180,6 +181,15 @@
#define IMGUI_IMPL_OPENGL_MAY_HAVE_EXTENSIONS
#endif

// [Debugging]
//#define IMGUI_IMPL_OPENGL_DEBUG
#ifdef IMGUI_IMPL_OPENGL_DEBUG
#include <stdio.h>
#define GL_CALL(_CALL) do { _CALL; GLenum gl_err = glGetError(); if (gl_err != 0) fprintf(stderr, "GL error 0x%x returned from '%s'.\n", gl_err, #_CALL); } while (0) // Call with error check
#else
#define GL_CALL(_CALL) _CALL // Call without error check
#endif

// OpenGL Data
struct ImGui_ImplOpenGL3_Data
{
Expand Down Expand Up @@ -276,11 +286,14 @@ bool ImGui_ImplOpenGL3_Init(const char* glsl_version)
if (strncmp(vendor, "Intel", 5) == 0)
bd->UseBufferSubData = true;
#endif
//printf("GL_MAJOR_VERSION = %d\nGL_MINOR_VERSION = %d\nGL_VENDOR = '%s'\nGL_RENDERER = '%s'\n", major, minor, (const char*)glGetString(GL_VENDOR), (const char*)glGetString(GL_RENDERER)); // [DEBUG]
#else
bd->GlVersion = 200; // GLES 2
#endif

#ifdef IMGUI_IMPL_OPENGL_DEBUG
printf("GL_MAJOR_VERSION = %d\nGL_MINOR_VERSION = %d\nGL_VENDOR = '%s'\nGL_RENDERER = '%s'\n", major, minor, (const char*)glGetString(GL_VENDOR), (const char*)glGetString(GL_RENDERER)); // [DEBUG]
#endif

#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
if (bd->GlVersion >= 320)
io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset; // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
Expand Down Expand Up @@ -384,7 +397,7 @@ static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_wid

// 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);
GL_CALL(glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height));
float L = draw_data->DisplayPos.x;
float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
float T = draw_data->DisplayPos.y;
Expand Down Expand Up @@ -414,14 +427,14 @@ static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_wid
#endif

// Bind vertex/index buffers and setup attributes for ImDrawVert
glBindBuffer(GL_ARRAY_BUFFER, bd->VboHandle);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bd->ElementsHandle);
glEnableVertexAttribArray(bd->AttribLocationVtxPos);
glEnableVertexAttribArray(bd->AttribLocationVtxUV);
glEnableVertexAttribArray(bd->AttribLocationVtxColor);
glVertexAttribPointer(bd->AttribLocationVtxPos, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos));
glVertexAttribPointer(bd->AttribLocationVtxUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv));
glVertexAttribPointer(bd->AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col));
GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, bd->VboHandle));
GL_CALL(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bd->ElementsHandle));
GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxPos));
GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxUV));
GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxColor));
GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxPos, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos)));
GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv)));
GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col)));
}

// OpenGL3 Render function.
Expand Down Expand Up @@ -481,7 +494,7 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
// The renderer would actually work without any VAO bound, but then our VertexAttrib calls would overwrite the default one currently bound.
GLuint vertex_array_object = 0;
#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
glGenVertexArrays(1, &vertex_array_object);
GL_CALL(glGenVertexArrays(1, &vertex_array_object));
#endif
ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);

Expand All @@ -505,20 +518,20 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
if (bd->VertexBufferSize < vtx_buffer_size)
{
bd->VertexBufferSize = vtx_buffer_size;
glBufferData(GL_ARRAY_BUFFER, bd->VertexBufferSize, NULL, GL_STREAM_DRAW);
GL_CALL(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);
GL_CALL(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);
GL_CALL(glBufferSubData(GL_ARRAY_BUFFER, 0, vtx_buffer_size, (const GLvoid*)cmd_list->VtxBuffer.Data));
GL_CALL(glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, idx_buffer_size, (const GLvoid*)cmd_list->IdxBuffer.Data));
}
else
{
glBufferData(GL_ARRAY_BUFFER, vtx_buffer_size, (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, idx_buffer_size, (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW);
GL_CALL(glBufferData(GL_ARRAY_BUFFER, vtx_buffer_size, (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW));
GL_CALL(glBufferData(GL_ELEMENT_ARRAY_BUFFER, idx_buffer_size, (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW));
}

for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
Expand All @@ -542,23 +555,23 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
continue;

// Apply scissor/clipping rectangle (Y is inverted in OpenGL)
glScissor((int)clip_min.x, (int)((float)fb_height - clip_max.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y));
GL_CALL(glScissor((int)clip_min.x, (int)((float)fb_height - clip_max.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y)));

// Bind texture, Draw
glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->GetTexID());
GL_CALL(glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->GetTexID()));
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
if (bd->GlVersion >= 320)
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);
GL_CALL(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
#endif
glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx)));
GL_CALL(glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx))));
}
}
}

// Destroy the temporary VAO
#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
glDeleteVertexArrays(1, &vertex_array_object);
GL_CALL(glDeleteVertexArrays(1, &vertex_array_object));
#endif

// Restore modified GL state
Expand Down Expand Up @@ -611,21 +624,21 @@ bool ImGui_ImplOpenGL3_CreateFontsTexture()
// Upload texture to graphics system
// (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
GLint last_texture;
glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
glGenTextures(1, &bd->FontTexture);
glBindTexture(GL_TEXTURE_2D, bd->FontTexture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
GL_CALL(glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture));
GL_CALL(glGenTextures(1, &bd->FontTexture));
GL_CALL(glBindTexture(GL_TEXTURE_2D, bd->FontTexture));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
#ifdef GL_UNPACK_ROW_LENGTH // Not on WebGL/ES
glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, 0));
#endif
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels));

// Store our identifier
io.Fonts->SetTexID((ImTextureID)(intptr_t)bd->FontTexture);

// Restore state
glBindTexture(GL_TEXTURE_2D, last_texture);
GL_CALL(glBindTexture(GL_TEXTURE_2D, last_texture));

return true;
}
Expand Down

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