GamePreview.h

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#pragma once
 
#if EDITOR
 
#include <cstdint>
#include <string>
#include <vector>
#include "imgui.h"
#include "EngineTypes.h"
 
class Image;
class Buffer;
class Camera3D;
 
struct ResolutionPreset
{
    std::string mName;
    uint32_t mWidth;
    uint32_t mHeight;
};
 
class GamePreview
{
public:
    void Enable();
    void Disable();
    void Render();
    void DrawPanel();
 
    // Called after a project loads. Picks the preferred preset (Project Settings
    // from EngineConfig, otherwise Build Target, otherwise built-in default) and
    // rebuilds the render targets so the panel matches immediately.
    void ApplyProjectDefaults();
 
    bool IsEnabled() const { return mEnabled; }
    uint32_t GetCurrentWidth() const { return mCurrentWidth; }
    uint32_t GetCurrentHeight() const { return mCurrentHeight; }
 
    // Selected preset resolution — persists across Disable() (unlike
    // GetCurrentWidth/Height, which track live render targets and reset to
    // 0 when the panel is closed). Returns the currently-selected preset,
    // or the current build profile's target platform, or a 640x480 default.
    uint32_t GetSelectedPresetWidth();
    uint32_t GetSelectedPresetHeight();
    std::string GetSelectedPresetName();
 
    // Capture the current color target into RGBA bytes (no disk write).
    // Returns false if the preview is not currently rendered (no color target).
    // Must be called from the main thread.
    bool CaptureScreenshotToMemory(std::vector<uint8_t>& outRgba,
                                   uint32_t& outWidth,
                                   uint32_t& outHeight);
 
    void BeginInputRemap();
    void EndInputRemap();
 
    // Hook support for addon resolution presets
    void AddResolutionPreset(const std::string& name, uint32_t w, uint32_t h);
    void RemoveResolutionPreset(const std::string& name);
    const std::vector<ResolutionPreset>& GetAddonPresets() const { return mAddonPresets; }
 
    // Returns the canonical preview resolution for a target platform.
    // Used by Game Preview's "Target Platform" preset and the Canvas inspector's
    // "Set Size To Build Profile Resolution" button.
    static void GetPlatformResolution(Platform platform, uint32_t& outWidth, uint32_t& outHeight, const char*& outName);
 
private:
    bool mEnabled = true;
    int32_t mSelectedPresetIndex = 0;
    // -1 is a reserved sentinel meaning "Active Camera" (follow whichever
    // camera is actually active, same as Viewport3D / fullscreen PIE),
    // rather than a pinned index into mCachedCameras.
    int32_t mSelectedCameraIndex = -1;
    bool mShowGizmos = false;
 
    // Render targets (recreated on resolution change)
    Image* mColorTarget = nullptr;
    Image* mDepthTarget = nullptr;
    ImTextureID mImGuiTexId = 0;
    uint32_t mCurrentWidth = 0;
    uint32_t mCurrentHeight = 0;
 
    // Screenshot
    bool mScreenshotRequested = false;
 
    // Built-in presets
    static const std::vector<ResolutionPreset> sBuiltInPresets;
 
    // Addon presets (populated by hooks)
    std::vector<ResolutionPreset> mAddonPresets;
 
    // Custom user presets (persisted to editor preferences)
    std::vector<ResolutionPreset> mCustomPresets;
    bool mCustomPresetsLoaded = false;
 
    // UI state for add-preset popup
    char mNewPresetName[128] = {};
    int32_t mNewPresetWidth = 1280;
    int32_t mNewPresetHeight = 720;
 
    // Cached camera list
    std::vector<Camera3D*> mCachedCameras;
 
    // Image display rect in window coords (captured by DrawPanel, used next frame)
    ImVec2 mImageMin = {0, 0};
    ImVec2 mImageMax = {0, 0};
 
    // Saved state for input remap
    int32_t mSavedMouseX = 0;
    int32_t mSavedMouseY = 0;
    uint32_t mSavedVpX = 0;
    uint32_t mSavedVpY = 0;
    uint32_t mSavedVpW = 0;
    uint32_t mSavedVpH = 0;
    bool mInputRemapActive = false;
 
    void CreateRenderTargets(uint32_t w, uint32_t h);
    void DestroyRenderTargets();
    void RefreshCameraList();
    void CaptureScreenshot();
    void LoadCustomPresets();
    void SaveCustomPresets();
    ResolutionPreset GetCurrentPreset();
    std::vector<ResolutionPreset> GetAllPresets();
};
 
GamePreview* GetGamePreview();
 
#endif