272 lines
11 KiB
C++
272 lines
11 KiB
C++
// dear imgui: Renderer Backend with shaders / programmatic pipeline
|
|
|
|
#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
|
|
#define _CRT_SECURE_NO_WARNINGS
|
|
#endif
|
|
|
|
#include "imgui.h"
|
|
|
|
#ifndef IMGUI_DISABLE
|
|
#include <stdio.h>
|
|
#include <stdint.h> // intptr_t
|
|
|
|
#include "imgui_impl_engine.h"
|
|
#include "render_shared.h"
|
|
#include "texture2d.h"
|
|
#include "gpu_buffer.h"
|
|
#include "shader.h"
|
|
#include "shadersystem.h"
|
|
#include "texturesmanager.h"
|
|
#include "renderdevice.h"
|
|
|
|
#define MAX_VB_SIZE sizeof(ImDrawVert) * 8192
|
|
#define MAX_IB_SIZE sizeof(ImDrawIdx) * 8192
|
|
|
|
InputLayoutDesc_t g_uiBaseInputLayout[] =
|
|
{
|
|
{ VERTEXATTR_VEC2, SHADERSEMANTIC_POSITION },
|
|
{ VERTEXATTR_VEC2, SHADERSEMANTIC_TEXCOORD },
|
|
{ VERTEXATTR_UINT, SHADERSEMANTIC_COLOR },
|
|
};
|
|
|
|
// Render Data
|
|
struct ImGui_Impl_IRender_Data
|
|
{
|
|
Texture2D *FontTexture;
|
|
Shader *ShaderHandle;
|
|
GPUBuffer *VboHandle, *ElementsHandle;
|
|
size_t VertexBufferSize;
|
|
size_t IndexBufferSize;
|
|
|
|
ImGui_Impl_IRender_Data() { memset((void*)this, 0, sizeof(*this)); }
|
|
};
|
|
|
|
// Backend data stored in io.BackendRendererUserData to allow support for multiple Dear ImGui contexts
|
|
// It is STRONGLY preferred that you use docking branch with multi-viewports (== single Dear ImGui context + multiple windows) instead of multiple Dear ImGui contexts.
|
|
static ImGui_Impl_IRender_Data* ImGui_GetBackendData()
|
|
{
|
|
return ImGui::GetCurrentContext() ? (ImGui_Impl_IRender_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
|
|
}
|
|
|
|
// Functions
|
|
bool ImGui_ImplEngine_Init(const char* glsl_version)
|
|
{
|
|
ImGuiIO& io = ImGui::GetIO();
|
|
IMGUI_CHECKVERSION();
|
|
IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");
|
|
|
|
// Setup backend capabilities flags
|
|
ImGui_Impl_IRender_Data* bd = IM_NEW(ImGui_Impl_IRender_Data)();
|
|
io.BackendRendererUserData = (void*)bd;
|
|
io.BackendRendererName = "imgui_impl_engine";
|
|
|
|
return true;
|
|
}
|
|
|
|
void ImGui_ImplEngine_Shutdown()
|
|
{
|
|
ImGui_Impl_IRender_Data* bd = ImGui_GetBackendData();
|
|
IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
|
|
ImGuiIO& io = ImGui::GetIO();
|
|
|
|
ImGui_ImplEngine_DestroyDeviceObjects();
|
|
io.BackendRendererName = nullptr;
|
|
io.BackendRendererUserData = nullptr;
|
|
io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
|
|
IM_DELETE(bd);
|
|
}
|
|
|
|
void ImGui_ImplEngine_NewFrame()
|
|
{
|
|
ImGui_Impl_IRender_Data* bd = ImGui_GetBackendData();
|
|
IM_ASSERT(bd != nullptr && "Context or backend not initialized! Did you call ImGui_ImplEngine_Init()?");
|
|
|
|
if (!bd->ShaderHandle)
|
|
ImGui_ImplEngine_CreateDeviceObjects();
|
|
if (!bd->FontTexture)
|
|
ImGui_ImplEngine_CreateFontsTexture();
|
|
}
|
|
|
|
static void ImGui_ImplEngine_SetupRenderState(ImDrawData* draw_data, int fb_width, int fb_height)
|
|
{
|
|
ImGui_Impl_IRender_Data* bd = ImGui_GetBackendData();
|
|
|
|
// Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, polygon fill
|
|
g_renderDevice->SetBlending(true);
|
|
g_renderDevice->SetBlendEquation(BE_FUNC_ADD);
|
|
g_renderDevice->SetBlendFuncSeparate(BF_SRC_ALPHA, BF_ONE_MINUS_SRC_ALPHA, BF_ONE, BF_ONE_MINUS_SRC_ALPHA);
|
|
|
|
// Rende states
|
|
g_renderDevice->SetCullFace(false);
|
|
g_renderDevice->SetDepthTest(false);
|
|
g_renderDevice->SetStencilTest(false);
|
|
g_renderDevice->SetScissorTest(true);
|
|
|
|
#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_POLYGON_MODE
|
|
if (bd->HasPolygonMode)
|
|
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
|
|
#endif
|
|
|
|
// Bind vertex/index buffers and setup attributes for ImDrawVert
|
|
g_renderDevice->SetVerticesBuffer(bd->VboHandle);
|
|
g_renderDevice->SetIndicesBuffer(bd->ElementsHandle);
|
|
|
|
// 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.
|
|
g_renderDevice->SetViewport(0, 0, (int)fb_width, (int)fb_height);
|
|
float L = draw_data->DisplayPos.x;
|
|
float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
|
|
float T = draw_data->DisplayPos.y;
|
|
float B = draw_data->DisplayPos.y + draw_data->DisplaySize.y;
|
|
const float ortho_projection[4][4] =
|
|
{
|
|
{ 2.0f/(R-L), 0.0f, 0.0f, 0.0f },
|
|
{ 0.0f, 2.0f/(T-B), 0.0f, 0.0f },
|
|
{ 0.0f, 0.0f, -1.0f, 0.0f },
|
|
{ (R+L)/(L-R), (T+B)/(B-T), 0.0f, 1.0f },
|
|
};
|
|
g_shaderSystem->SetShader(bd->ShaderHandle);
|
|
g_shaderSystem->SetUniformSampler(bd->ShaderHandle, SAMPLER_ALBEDO, 0);
|
|
g_shaderSystem->SetUniformMatrix(bd->ShaderHandle, UNIFORM_PROJ_MATRIX, &ortho_projection[0][0]);
|
|
}
|
|
|
|
// OpenGL3 Render function.
|
|
// Note that this implementation is little overcomplicated because we are saving/setting up/restoring every OpenGL state explicitly.
|
|
// This is in order to be able to run within an OpenGL engine that doesn't do so.
|
|
void ImGui_ImplEngine_RenderDrawData(ImDrawData* draw_data)
|
|
{
|
|
// Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
|
|
int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
|
|
int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
|
|
if (fb_width <= 0 || fb_height <= 0)
|
|
return;
|
|
|
|
ImGui_Impl_IRender_Data* bd = ImGui_GetBackendData();
|
|
|
|
ImGui_ImplEngine_SetupRenderState(draw_data, fb_width, fb_height);
|
|
|
|
// Will project scissor/clipping rectangles into framebuffer space
|
|
ImVec2 clip_off = draw_data->DisplayPos; // (0,0) unless using multi-viewports
|
|
ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
|
|
|
|
// Render command lists
|
|
for (int n = 0; n < draw_data->CmdListsCount; n++)
|
|
{
|
|
const ImDrawList* draw_list = draw_data->CmdLists[n];
|
|
|
|
// Upload vertex/index buffers
|
|
const size_t vtx_buffer_size = (size_t)draw_list->VtxBuffer.Size * (int)sizeof(ImDrawVert);
|
|
const size_t idx_buffer_size = (size_t)draw_list->IdxBuffer.Size * (int)sizeof(ImDrawIdx);
|
|
//if (bd->UseBufferSubData)
|
|
//{
|
|
// if (bd->VertexBufferSize < vtx_buffer_size)
|
|
// {
|
|
// bd->VertexBufferSize = vtx_buffer_size;
|
|
// GL_CALL(glBufferData(GL_ARRAY_BUFFER, bd->VertexBufferSize, nullptr, GL_STREAM_DRAW));
|
|
// }
|
|
// if (bd->IndexBufferSize < idx_buffer_size)
|
|
// {
|
|
// bd->IndexBufferSize = idx_buffer_size;
|
|
// GL_CALL(glBufferData(GL_ELEMENT_ARRAY_BUFFER, bd->IndexBufferSize, nullptr, GL_STREAM_DRAW));
|
|
// }
|
|
// GL_CALL(glBufferSubData(GL_ARRAY_BUFFER, 0, vtx_buffer_size, (const GLvoid*)draw_list->VtxBuffer.Data));
|
|
// GL_CALL(glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, idx_buffer_size, (const GLvoid*)draw_list->IdxBuffer.Data));
|
|
//}
|
|
//else
|
|
{
|
|
bd->VboHandle->UpdateBuffer(draw_list->VtxBuffer.Data, vtx_buffer_size);
|
|
bd->ElementsHandle->UpdateBuffer(draw_list->IdxBuffer.Data, idx_buffer_size);
|
|
}
|
|
|
|
for (int cmd_i = 0; cmd_i < draw_list->CmdBuffer.Size; cmd_i++)
|
|
{
|
|
const ImDrawCmd* pcmd = &draw_list->CmdBuffer[cmd_i];
|
|
if (pcmd->UserCallback != nullptr)
|
|
{
|
|
// User callback, registered via ImDrawList::AddCallback()
|
|
// (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
|
|
if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
|
|
ImGui_ImplEngine_SetupRenderState(draw_data, fb_width, fb_height);
|
|
else
|
|
pcmd->UserCallback(draw_list, pcmd);
|
|
}
|
|
else
|
|
{
|
|
// Project scissor/clipping rectangles into framebuffer space
|
|
ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
|
|
ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
|
|
if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)
|
|
continue;
|
|
|
|
// Apply scissor/clipping rectangle (Y is inverted in OpenGL)
|
|
g_renderDevice->SetScissor((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
|
|
g_texturesManager->SetTexture(0, (Texture2D*)(intptr_t)pcmd->GetTexID());
|
|
|
|
g_renderDevice->DrawElements(PT_TRIANGLES, (uint32_t)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? true : false, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx)));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
bool ImGui_ImplEngine_CreateFontsTexture()
|
|
{
|
|
ImGuiIO& io = ImGui::GetIO();
|
|
ImGui_Impl_IRender_Data* bd = ImGui_GetBackendData();
|
|
|
|
// Build texture atlas
|
|
unsigned char* pixels;
|
|
int width, height;
|
|
io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height); // Load as RGBA 32-bit (75% of the memory is wasted, but default font is so small) because it is more likely to be compatible with user's existing shaders. If your ImTextureId represent a higher-level concept than just a GL texture id, consider calling GetTexDataAsAlpha8() instead to save on GPU memory.
|
|
|
|
// 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)
|
|
bd->FontTexture = g_texturesManager->CreateManual2D("ImGuiFontTexture", width, height, PF_R8G8B8A8, pixels, false);
|
|
|
|
// Store identifier
|
|
io.Fonts->SetTexID((ImTextureID)(intptr_t)bd->FontTexture);
|
|
|
|
return true;
|
|
}
|
|
|
|
void ImGui_ImplEngine_DestroyFontsTexture()
|
|
{
|
|
ImGuiIO& io = ImGui::GetIO();
|
|
ImGui_Impl_IRender_Data* bd = ImGui_GetBackendData();
|
|
if (bd->FontTexture)
|
|
{
|
|
io.Fonts->SetTexID(0);
|
|
bd->FontTexture = 0;
|
|
}
|
|
}
|
|
|
|
bool ImGui_ImplEngine_CreateDeviceObjects()
|
|
{
|
|
ImGui_Impl_IRender_Data* bd = ImGui_GetBackendData();
|
|
|
|
// Create shaders
|
|
bd->ShaderHandle = g_shaderSystem->CreateShader("ui_base", "data/shaders/ui_base.vs", "data/shaders/ui_base.ps",
|
|
g_uiBaseInputLayout, sizeof(g_uiBaseInputLayout) / sizeof(g_uiBaseInputLayout[0]));
|
|
|
|
// Create buffers
|
|
bd->VboHandle = g_renderDevice->CreateVertexBuffer(nullptr, MAX_VB_SIZE, true);
|
|
bd->ElementsHandle = g_renderDevice->CreateIndexBuffer(nullptr, MAX_IB_SIZE, true);
|
|
|
|
ImGui_ImplEngine_CreateFontsTexture();
|
|
|
|
return true;
|
|
}
|
|
|
|
void ImGui_ImplEngine_DestroyDeviceObjects()
|
|
{
|
|
ImGui_Impl_IRender_Data* bd = ImGui_GetBackendData();
|
|
if (bd->VboHandle) { delete bd->VboHandle; bd->VboHandle = 0; }
|
|
if (bd->ElementsHandle) { delete bd->ElementsHandle; bd->ElementsHandle = 0; }
|
|
ImGui_ImplEngine_DestroyFontsTexture();
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
|
|
#endif // #ifndef IMGUI_DISABLE
|