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cup_edit/ios/include/filagui/ImGuiHelper.h
2022-12-05 17:51:44 +08:00

103 lines
4.1 KiB
C++

/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef FILAGUI_IMGUIHELPER_H_
#define FILAGUI_IMGUIHELPER_H_
#include <vector>
#include <functional>
#include <filament/Engine.h>
#include <filament/IndexBuffer.h>
#include <filament/Material.h>
#include <filament/MaterialInstance.h>
#include <filament/Texture.h>
#include <filament/TextureSampler.h>
#include <filament/VertexBuffer.h>
#include <filament/View.h>
#include <utils/Entity.h>
#include <utils/Path.h>
struct ImDrawData;
struct ImGuiIO;
struct ImGuiContext;
namespace filagui {
// Translates ImGui's draw commands into Filament primitives, textures, vertex buffers, etc.
// Creates a UI-specific Scene object and populates it with a Renderable. Does not handle
// event processing; clients can simply call ImGui::GetIO() directly and set the mouse state.
class UTILS_PUBLIC ImGuiHelper {
public:
// Using std::function instead of a vanilla C callback to make it easy for clients to pass in
// lambdas that have captures.
using Callback = std::function<void(filament::Engine*, filament::View*)>;
// The constructor creates its own Scene and places it in the given View.
ImGuiHelper(filament::Engine* engine, filament::View* view, const utils::Path& fontPath,
ImGuiContext* imGuiContext = nullptr);
~ImGuiHelper();
// Informs ImGui of the current display size, as well as a scaling factor when scissoring.
void setDisplaySize(int width, int height, float scaleX = 1.0f,
float scaleY = 1.0f, bool flipVertical = false);
// High-level utility method that takes a callback for creating all ImGui windows and widgets.
// Clients are responsible for rendering the View. This should be called on every frame,
// regardless of whether the Renderer wants to skip or not.
void render(float timeStepInSeconds, Callback imguiCommands);
// Low-level alternative to render() that consumes an ImGui command list and translates it into
// various Filament calls. This includes updating the vertex buffer, setting up material
// instances, and rebuilding the Renderable component that encompasses the entire UI. Since this
// makes Filament calls, it must be called from the main thread.
void processImGuiCommands(ImDrawData* commands, const ImGuiIO& io);
// Helper method called after resolving fontPath; public so fonts can be added by caller.
void createAtlasTexture(filament::Engine* engine);
// Returns the client-owned view, useful for drawing 2D overlays.
filament::View* getView() const { return mView; }
private:
void createBuffers(int numRequiredBuffers);
void populateVertexData(size_t bufferIndex, size_t vbSizeInBytes, void* vbData,
size_t ibSizeInBytes, void* ibData);
void createVertexBuffer(size_t bufferIndex, size_t capacity);
void createIndexBuffer(size_t bufferIndex, size_t capacity);
void syncThreads();
filament::Engine* mEngine;
filament::View* mView; // The view is owned by the client.
filament::Scene* mScene;
filament::Material* mMaterial = nullptr;
filament::Camera* mCamera = nullptr;
std::vector<filament::VertexBuffer*> mVertexBuffers;
std::vector<filament::IndexBuffer*> mIndexBuffers;
std::vector<filament::MaterialInstance*> mMaterialInstances;
utils::Entity mRenderable;
utils::Entity mCameraEntity;
filament::Texture* mTexture = nullptr;
bool mHasSynced = false;
ImGuiContext* mImGuiContext;
filament::TextureSampler mSampler;
bool mFlipVertical = false;
};
} // namespace filagui
#endif /* FILAGUI_IMGUIHELPER_H_ */