PowerToys/src/modules/MeasureTool/MeasureToolCore/MeasureToolOverlayUI.cpp

#include "pch.h"

#include "BGRATextureView.h"
#include "Clipboard.h"
#include "CoordinateSystemConversion.h"
#include "constants.h"
#include "MeasureToolOverlayUI.h"

#include <common/utils/window.h>

namespace
{
    inline std::pair<D2D_POINT_2F, D2D_POINT_2F> ComputeCrossFeetLine(D2D_POINT_2F center, const bool horizontal)
    {
        D2D_POINT_2F start = center, end = center;
        // Computing in this way to achieve pixel-perfect axial symmetry of aliased D2D lines 
        if (horizontal)
        {
            start.x -= consts::FEET_HALF_LENGTH + 1.f;
            end.x += consts::FEET_HALF_LENGTH;

            start.y += 1.f;
            end.y += 1.f;
        }
        else
        {
            start.y -= consts::FEET_HALF_LENGTH + 1.f;
            end.y += consts::FEET_HALF_LENGTH;

            start.x += 1.f;
            end.x += 1.f;
        }

        return { start, end };
    }
}

winrt::com_ptr<ID2D1Bitmap> ConvertID3D11Texture2DToD2D1Bitmap(wil::com_ptr<ID2D1HwndRenderTarget> rt,
                                                               winrt::com_ptr<ID3D11Texture2D> texture)
{
    std::lock_guard guard{ gpuAccessLock };

    auto dxgiSurface = texture.try_as<IDXGISurface>();
    if (!dxgiSurface)
        return nullptr;

    DXGI_MAPPED_RECT bitmap2Dmap = {};
    HRESULT hr = dxgiSurface->Map(&bitmap2Dmap, DXGI_MAP_READ);
    if (FAILED(hr))
    {
        return nullptr;
    }

    D2D1_BITMAP_PROPERTIES props = { .pixelFormat = rt->GetPixelFormat() };
    rt->GetDpi(&props.dpiX, &props.dpiY);
    const auto sizeF = rt->GetSize();
    winrt::com_ptr<ID2D1Bitmap> bitmap;
    if (FAILED(rt->CreateBitmap(D2D1::SizeU(static_cast<uint32_t>(sizeF.width),
                                            static_cast<uint32_t>(sizeF.height)),
                                bitmap2Dmap.pBits,
                                bitmap2Dmap.Pitch,
                                props,
                                bitmap.put())))
        return nullptr;
    if (FAILED(dxgiSurface->Unmap()))
        return nullptr;

    return bitmap;
}

LRESULT CALLBACK MeasureToolWndProc(HWND window, UINT message, WPARAM wparam, LPARAM lparam) noexcept
{
    switch (message)
    {
    case WM_CURSOR_LEFT_MONITOR:
    {
        if (auto state = GetWindowParam<Serialized<MeasureToolState>*>(window))
        {
            state->Access([&](MeasureToolState& s) {
                s.perScreen[window].measuredEdges = {};
            });
        }
        break;
    }
    case WM_NCHITTEST:
        return HTCLIENT;
    case WM_CREATE:
    {
        auto state = GetWindowCreateParam<Serialized<MeasureToolState>*>(lparam);
        StoreWindowParam(window, state);

#if !defined(DEBUG_OVERLAY)
        for (; ShowCursor(false) > 0;)
            ;
#endif
        break;
    }
    case WM_ERASEBKGND:
        return 1;
    case WM_KEYUP:
        if (wparam == VK_ESCAPE)
        {
            PostMessageW(window, WM_CLOSE, {}, {});
        }
        break;
    case WM_RBUTTONUP:
        PostMessageW(window, WM_CLOSE, {}, {});
        break;
    case WM_LBUTTONUP:
        if (auto state = GetWindowParam<Serialized<MeasureToolState>*>(window))
        {
            state->Read([](const MeasureToolState& s) { s.commonState->overlayBoxText.Read([](const OverlayBoxText& text) {
                                                            SetClipBoardToText(text.buffer);
                                                        }); });
        }
        break;
    case WM_MOUSEWHEEL:
        if (auto state = GetWindowParam<Serialized<MeasureToolState>*>(window))
        {
            const int8_t step = static_cast<short>(HIWORD(wparam)) < 0 ? -consts::MOUSE_WHEEL_TOLERANCE_STEP : consts::MOUSE_WHEEL_TOLERANCE_STEP;
            state->Access([step](MeasureToolState& s) {
                int wideVal = s.global.pixelTolerance;
                wideVal += step;
                s.global.pixelTolerance = static_cast<uint8_t>(std::clamp(wideVal, 0, 255));
            });
        }
        break;
    }

    return DefWindowProcW(window, message, wparam, lparam);
}

void DrawMeasureToolTick(const CommonState& commonState,
                         Serialized<MeasureToolState>& toolState,
                         HWND window,
                         D2DState& d2dState)
{
    bool continuousCapture = {};
    bool drawFeetOnCross = {};
    bool drawHorizontalCrossLine = true;
    bool drawVerticalCrossLine = true;
    RECT measuredEdges{};
    MeasureToolState::Mode mode = {};
    winrt::com_ptr<ID2D1Bitmap> backgroundBitmap;
    winrt::com_ptr<ID3D11Texture2D> backgroundTextureToConvert;

    toolState.Read([&](const MeasureToolState& state) {
        continuousCapture = state.global.continuousCapture;
        drawFeetOnCross = state.global.drawFeetOnCross;
        mode = state.global.mode;

        if (auto it = state.perScreen.find(window); it != end(state.perScreen))
        {
            const auto& perScreen = it->second;
            measuredEdges = perScreen.measuredEdges;

            if (continuousCapture)
                return;

            if (perScreen.capturedScreenBitmap)
            {
                backgroundBitmap = perScreen.capturedScreenBitmap;
            }
            else if (perScreen.capturedScreenTexture)
            {
                backgroundTextureToConvert = perScreen.capturedScreenTexture;
            }
        }
    });
    switch (mode)
    {
    case MeasureToolState::Mode::Cross:
        drawHorizontalCrossLine = true;
        drawVerticalCrossLine = true;
        break;
    case MeasureToolState::Mode::Vertical:
        drawHorizontalCrossLine = false;
        drawVerticalCrossLine = true;
        break;
    case MeasureToolState::Mode::Horizontal:
        drawHorizontalCrossLine = true;
        drawVerticalCrossLine = false;
        break;
    }

    if (!continuousCapture && !backgroundBitmap && backgroundTextureToConvert)
    {
        backgroundBitmap = ConvertID3D11Texture2DToD2D1Bitmap(d2dState.rt, backgroundTextureToConvert);
        if (backgroundBitmap)
        {
            toolState.Access([&](MeasureToolState& state) {
                state.perScreen[window].capturedScreenTexture = {};
                state.perScreen[window].capturedScreenBitmap = backgroundBitmap;
            });
        }
    }

    if (continuousCapture || !backgroundBitmap)
        d2dState.rt->Clear();

    // Add 1px to each dim, since the range we obtain from measuredEdges is inclusive.
    const float hMeasure = static_cast<float>(measuredEdges.right - measuredEdges.left + 1);
    const float vMeasure = static_cast<float>(measuredEdges.bottom - measuredEdges.top + 1);

    // Prevent drawing until we get the first capture
    const bool hasMeasure = (measuredEdges.right != measuredEdges.left) && (measuredEdges.bottom != measuredEdges.top);
    if (!hasMeasure)
    {
        return;
    }

    if (!continuousCapture && backgroundBitmap)
    {
        d2dState.rt->DrawBitmap(backgroundBitmap.get());
    }

    const auto previousAliasingMode = d2dState.rt->GetAntialiasMode();
    // Anti-aliasing is creating artifacts. Aliasing is for drawing straight lines.
    d2dState.rt->SetAntialiasMode(D2D1_ANTIALIAS_MODE_ALIASED);

    const auto cursorPos = convert::FromSystemToRelativeForDirect2D(window, commonState.cursorPosSystemSpace);

    if (drawHorizontalCrossLine)
    {
        const D2D_POINT_2F hLineStart{ .x = static_cast<float>(measuredEdges.left), .y = static_cast<float>(cursorPos.y) };
        D2D_POINT_2F hLineEnd{ .x = hLineStart.x + hMeasure, .y = hLineStart.y };
        d2dState.rt->DrawLine(hLineStart, hLineEnd, d2dState.solidBrushes[Brush::line].get());

        if (drawFeetOnCross && !continuousCapture)
        {
            // To fill all pixels which are close, we call DrawLine with end point one pixel too far, since
            // it doesn't get filled, i.e. end point of the range is excluded. However, we want to draw cross
            // feet *on* the last pixel row, so we must subtract 1px from the corresponding axis.
            hLineEnd.x -= 1.f;
            auto [left_start, left_end] = ComputeCrossFeetLine(hLineStart, false);
            auto [right_start, right_end] = ComputeCrossFeetLine(hLineEnd, false);
            d2dState.rt->DrawLine(left_start, left_end, d2dState.solidBrushes[Brush::line].get());
            d2dState.rt->DrawLine(right_start, right_end, d2dState.solidBrushes[Brush::line].get());
        }
    }

    if (drawVerticalCrossLine)
    {
        const D2D_POINT_2F vLineStart{ .x = static_cast<float>(cursorPos.x), .y = static_cast<float>(measuredEdges.top) };
        D2D_POINT_2F vLineEnd{ .x = vLineStart.x, .y = vLineStart.y + vMeasure };
        d2dState.rt->DrawLine(vLineStart, vLineEnd, d2dState.solidBrushes[Brush::line].get());

        if (drawFeetOnCross && !continuousCapture)
        {
            vLineEnd.y -= 1.f;
            auto [top_start, top_end] = ComputeCrossFeetLine(vLineStart, true);
            auto [bottom_start, bottom_end] = ComputeCrossFeetLine(vLineEnd, true);
            d2dState.rt->DrawLine(top_start, top_end, d2dState.solidBrushes[Brush::line].get());
            d2dState.rt->DrawLine(bottom_start, bottom_end, d2dState.solidBrushes[Brush::line].get());
        }
    }

    // After drawing the lines, restore anti aliasing to draw the measurement tooltip.
    d2dState.rt->SetAntialiasMode(previousAliasingMode);

    uint32_t measureStringBufLen = 0;

    OverlayBoxText text;
    std::optional<size_t> crossSymbolPos;
    switch (mode)
    {
    case MeasureToolState::Mode::Cross:
        measureStringBufLen = swprintf_s(text.buffer.data(),
                                         text.buffer.size(),
                                         L"%.0f × %.0f",
                                         hMeasure,
                                         vMeasure);
        crossSymbolPos = wcschr(text.buffer.data(), L' ') - text.buffer.data() + 1;
        break;
    case MeasureToolState::Mode::Vertical:
        measureStringBufLen = swprintf_s(text.buffer.data(),
                                         text.buffer.size(),
                                         L"%.0f",
                                         vMeasure);
        break;
    case MeasureToolState::Mode::Horizontal:
        measureStringBufLen = swprintf_s(text.buffer.data(),
                                         text.buffer.size(),
                                         L"%.0f",
                                         hMeasure);
        break;
    }

    commonState.overlayBoxText.Access([&](OverlayBoxText& v) {
        v = text;
    });

    d2dState.DrawTextBox(text.buffer.data(),
                         measureStringBufLen,
                         crossSymbolPos,
                         static_cast<float>(cursorPos.x),
                         static_cast<float>(cursorPos.y),
                         true,
                         window);
}