terminal/src/renderer/dx/CustomTextRenderer.h

// Copyright (c) Microsoft Corporation.
// Licensed under the MIT license.

#pragma once

#include <wrl/implements.h>

namespace Microsoft::Console::Render
{
    struct DrawingContext
    {
        DrawingContext(ID2D1RenderTarget* renderTarget,
                       ID2D1Brush* foregroundBrush,
                       ID2D1Brush* backgroundBrush,
                       IDWriteFactory* dwriteFactory,
                       const DWRITE_LINE_SPACING spacing,
                       const D2D_SIZE_F cellSize,
                       const D2D1_DRAW_TEXT_OPTIONS options = D2D1_DRAW_TEXT_OPTIONS_NONE)
        {
            this->renderTarget = renderTarget;
            this->foregroundBrush = foregroundBrush;
            this->backgroundBrush = backgroundBrush;
            this->dwriteFactory = dwriteFactory;
            this->spacing = spacing;
            this->cellSize = cellSize;
            this->options = options;
        }

        ID2D1RenderTarget* renderTarget;
        ID2D1Brush* foregroundBrush;
        ID2D1Brush* backgroundBrush;
        IDWriteFactory* dwriteFactory;
        DWRITE_LINE_SPACING spacing;
        D2D_SIZE_F cellSize;
        D2D1_DRAW_TEXT_OPTIONS options;
    };

    class CustomTextRenderer : public ::Microsoft::WRL::RuntimeClass<::Microsoft::WRL::RuntimeClassFlags<::Microsoft::WRL::ClassicCom |
        ::Microsoft::WRL::InhibitFtmBase>,
        IDWriteTextRenderer>
    {
    public:

        // http://www.charlespetzold.com/blog/2014/01/Character-Formatting-Extensions-with-DirectWrite.html
        // https://docs.microsoft.com/en-us/windows/desktop/DirectWrite/how-to-implement-a-custom-text-renderer

        // IDWritePixelSnapping methods
        [[nodiscard]]
        virtual HRESULT STDMETHODCALLTYPE IsPixelSnappingDisabled(void* clientDrawingContext,
                                                                  _Out_ BOOL* isDisabled) override;

        [[nodiscard]]
        virtual HRESULT STDMETHODCALLTYPE GetPixelsPerDip(void* clientDrawingContext,
                                                          _Out_ FLOAT* pixelsPerDip) override;

        [[nodiscard]]
        virtual HRESULT STDMETHODCALLTYPE GetCurrentTransform(void* clientDrawingContext,
                                                              _Out_ DWRITE_MATRIX* transform) override;

        // IDWriteTextRenderer methods
        [[nodiscard]]
        virtual HRESULT STDMETHODCALLTYPE DrawGlyphRun(void* clientDrawingContext,
                                                       FLOAT baselineOriginX,
                                                       FLOAT baselineOriginY,
                                                       DWRITE_MEASURING_MODE measuringMode,
                                                       _In_ const DWRITE_GLYPH_RUN* glyphRun,
                                                       _In_ const DWRITE_GLYPH_RUN_DESCRIPTION* glyphRunDescription,
                                                       IUnknown* clientDrawingEffect) override;

        [[nodiscard]]
        virtual HRESULT STDMETHODCALLTYPE DrawUnderline(void* clientDrawingContext,
                                                        FLOAT baselineOriginX,
                                                        FLOAT baselineOriginY,
                                                        _In_ const DWRITE_UNDERLINE* underline,
                                                        IUnknown* clientDrawingEffect) override;

        [[nodiscard]]
        virtual HRESULT STDMETHODCALLTYPE DrawStrikethrough(void* clientDrawingContext,
                                                            FLOAT baselineOriginX,
                                                            FLOAT baselineOriginY,
                                                            _In_ const DWRITE_STRIKETHROUGH * strikethrough,
                                                            IUnknown* clientDrawingEffect) override;

        [[nodiscard]]
        virtual HRESULT STDMETHODCALLTYPE DrawInlineObject(void* clientDrawingContext,
                                                           FLOAT originX,
                                                           FLOAT originY,
                                                           IDWriteInlineObject* inlineObject,
                                                           BOOL isSideways,
                                                           BOOL isRightToLeft,
                                                           IUnknown* clientDrawingEffect) override;
    private:
        void _FillRectangle(void* clientDrawingContext,
                            IUnknown* clientDrawingEffect,
                            float x, float y, float width, float thickness,
                            DWRITE_READING_DIRECTION readingDirection,
                            DWRITE_FLOW_DIRECTION flowDirection);

        [[nodiscard]]
        HRESULT _DrawBasicGlyphRun(DrawingContext* clientDrawingContext,
                                   D2D1_POINT_2F baselineOrigin,
                                   DWRITE_MEASURING_MODE measuringMode,
                                   _In_ const DWRITE_GLYPH_RUN* glyphRun,
                                   _In_ const DWRITE_GLYPH_RUN_DESCRIPTION* glyphRunDescription,
                                   ID2D1Brush* brush);

        [[nodiscard]]
        HRESULT _DrawBasicGlyphRunManually(DrawingContext*clientDrawingContext,
                                           D2D1_POINT_2F baselineOrigin,
                                           DWRITE_MEASURING_MODE measuringMode,
                                           _In_ const DWRITE_GLYPH_RUN* glyphRun,
                                           _In_ const DWRITE_GLYPH_RUN_DESCRIPTION* glyphRunDescription);

        [[nodiscard]]
        HRESULT _DrawGlowGlyphRun(DrawingContext* clientDrawingContext,
                                  D2D1_POINT_2F baselineOrigin,
                                  DWRITE_MEASURING_MODE measuringMode,
                                  _In_ const DWRITE_GLYPH_RUN* glyphRun,
                                  _In_ const DWRITE_GLYPH_RUN_DESCRIPTION* glyphRunDescription);
    };
}