C# Cairo.Context.DrawLine方法代码示例

        /// <summary>
        /// Draws the text.
        /// </summary>
        /// <param name="showCursor">Whether or not to show the mouse cursor in the drawing.</param>
        /// <param name="useTextLayer">Whether or not to use the TextLayer (as opposed to the Userlayer).</param>
        private void RedrawText(bool showCursor, bool useTextLayer)
        {
            Rectangle r = CurrentTextEngine.GetLayoutBounds();
            r.Inflate(10 + OutlineWidth, 10 + OutlineWidth);
            CurrentTextBounds = r;

            Rectangle cursorBounds = Rectangle.Zero;

            Cairo.ImageSurface surf;

            if (!useTextLayer)
            {
                //Draw text on the current UserLayer's surface as finalized text.
                surf = PintaCore.Workspace.ActiveDocument.CurrentUserLayer.Surface;
            }
            else
            {
                //Draw text on the current UserLayer's TextLayer's surface as re-editable text.
                surf = PintaCore.Workspace.ActiveDocument.CurrentUserLayer.TextLayer.Surface;

                ClearTextLayer();
            }

            using (var g = new Cairo.Context (surf)) {
                g.Save ();

                // Show selection if on text layer
                if (useTextLayer) {
                    // Selected Text
                    Cairo.Color c = new Cairo.Color (0.7, 0.8, 0.9, 0.5);
                    foreach (Rectangle rect in CurrentTextEngine.SelectionRectangles)
                        g.FillRectangle (rect.ToCairoRectangle (), c);
                }
                g.AppendPath (PintaCore.Workspace.ActiveDocument.Selection.SelectionPath);
                g.FillRule = Cairo.FillRule.EvenOdd;
                g.Clip ();

                g.MoveTo (new Cairo.PointD (CurrentTextEngine.Origin.X, CurrentTextEngine.Origin.Y));

                g.Color = PintaCore.Palette.PrimaryColor;

                //Fill in background
                if (BackgroundFill) {
                    using (var g2 = new Cairo.Context (surf)) {
                        g2.FillRectangle(CurrentTextEngine.GetLayoutBounds().ToCairoRectangle(), PintaCore.Palette.SecondaryColor);
                    }
                }

                // Draw the text
                if (FillText)
                    Pango.CairoHelper.ShowLayout (g, CurrentTextEngine.Layout);

                if (FillText && StrokeText) {
                    g.Color = PintaCore.Palette.SecondaryColor;
                    g.LineWidth = OutlineWidth;

                    Pango.CairoHelper.LayoutPath (g, CurrentTextEngine.Layout);
                    g.Stroke ();
                } else if (StrokeText) {
                    g.Color = PintaCore.Palette.PrimaryColor;
                    g.LineWidth = OutlineWidth;

                    Pango.CairoHelper.LayoutPath (g, CurrentTextEngine.Layout);
                    g.Stroke ();
                }

                if (showCursor) {
                    var loc = CurrentTextEngine.GetCursorLocation ();

                    g.Antialias = Cairo.Antialias.None;
                    g.DrawLine (new Cairo.PointD (loc.X, loc.Y), new Cairo.PointD (loc.X, loc.Y + loc.Height), new Cairo.Color (0, 0, 0, 1), 1);

                    cursorBounds = Rectangle.Inflate (loc, 2, 10);
                }

                g.Restore ();

                if (useTextLayer && (is_editing || ctrlKey) && !CurrentTextEngine.IsEmpty())
                {
                    //Draw the text edit rectangle.

                    g.Save();

                    g.Translate(.5, .5);

                    using (Cairo.Path p = g.CreateRectanglePath(new Cairo.Rectangle(CurrentTextBounds.Left, CurrentTextBounds.Top,
                        CurrentTextBounds.Width, CurrentTextBounds.Height - FontSize)))
                    {
                        g.AppendPath(p);
                    }

                    g.LineWidth = 1;

                    g.Color = new Cairo.Color(1, 1, 1);
                    g.StrokePreserve();
//.........这里部分代码省略.........

        private unsafe void DrawText(Cairo.ImageSurface dst, string textFont, string text, Point pt, Size measuredSize, bool antiAliasing, Cairo.ImageSurface brush8x8)
        {
            Point pt2 = pt;
            Size measuredSize2 = measuredSize;
            int offset = FontHeight;
            pt.X -= offset;
            measuredSize.Width += 2 * offset;
            Rectangle dstRect = new Rectangle (pt, measuredSize);
            Rectangle dstRectClipped = Rectangle.Intersect (dstRect, PintaCore.Layers.ToolLayer.Surface.GetBounds ());
            PintaCore.Layers.ToolLayer.Clear ();

            if (dstRectClipped.Width == 0 || dstRectClipped.Height == 0) {
                return;
            }

            // We only use the first 8,8 of brush
            using (Cairo.Context toolctx = new Cairo.Context (PintaCore.Layers.ToolLayer.Surface)) {
                //toolctx.FillRectangle (new Cairo.Rectangle(0, 0, 800, 600), new Cairo.Color (0, 0, 0));
                toolctx.FillRectangle (dstRect.ToCairoRectangle (), new Cairo.Color (1, 1, 1));
                Cairo.ImageSurface surf = PintaCore.Layers.ToolLayer.Surface;
                //TODO find how create a surface a of a particular area of a bigger surface!
                //for moment work with the whole surface!
                if (measuredSize.Width > 0 && measuredSize.Height > 0) {
                    //dstRectClipped
                    using (Cairo.Context ctx = new Cairo.Context (PintaCore.Layers.ToolLayer.Surface)) {
                        Cairo.TextExtents te = TextExtents (ctx, text);
                        //new Cairo.PointD(dstRect.X - dstRectClipped.X + offset, dstRect.Y - dstRectClipped.Y),
                        ctx.DrawText (new Cairo.PointD (dstRect.X + offset - te.XBearing, dstRect.Y - te.YBearing), textFont, FontSlant, FontWeight, FontSize, PintaCore.Palette.PrimaryColor, text);

                        if (underscore_btn.Active) {
                            int lineSize = 1;
                            Cairo.FontExtents fe = FontExtents (ctx, text);
                            ctx.DrawLine (new Cairo.PointD (pt2.X, dstRect.Bottom + fe.Descent), new Cairo.PointD (dstRect.Right - offset, dstRect.Bottom + fe.Descent), PintaCore.Palette.PrimaryColor, lineSize);
                        }
                    }
                    PintaCore.Workspace.Invalidate (dstRectClipped);
                }

                // Mask out anything that isn't within the user's clip region (selected region)
                using (Region clip = Region.Rectangle (PintaCore.Layers.SelectionPath.GetBounds ())) {
                    clip.Xor (Region.Rectangle (dstRectClipped));
                    // invert
                    clip.Intersect (Region.Rectangle (new Rectangle (pt, measuredSize)));
                    toolctx.FillRegion (clip, new Cairo.Color (1, 1, 1, 1));
                }

                int skipX;

                if (pt.X < 0) {
                    skipX = -pt.X;
                } else {
                    skipX = 0;
                }

                int xEnd = Math.Min (dst.Width, pt.X + measuredSize.Width);

                bool blending = false;
                //AppEnvironment.AlphaBlending;
                //if (dst.IsColumnVisible(pt.X + skipX))
                //{
                for (int y = pt.Y; y < pt.Y + measuredSize.Height; ++y) {
                    //if (!dst.IsRowVisible(y))
                    //{
                    //    continue;
                    //}

                    ColorBgra* dstPtr = dst.GetPointAddressUnchecked (pt.X + skipX, y);
                    ColorBgra* srcPtr = PintaCore.Layers.ToolLayer.Surface.GetPointAddress (pt.X + skipX, y);
                    ColorBgra* brushPtr = brush8x8.GetRowAddressUnchecked (y & 7);

                    for (int x = pt.X + skipX; x < xEnd; ++x) {
                        ColorBgra srcPixel = *srcPtr;
                        ColorBgra dstPixel = *dstPtr;
                        ColorBgra brushPixel = brushPtr[x & 7];

                        int alpha = ((255 - srcPixel.R) * brushPixel.A) / 255;
                        // we could use srcPixel.R, .G, or .B -- the choice here is arbitrary
                        brushPixel.A = (byte)alpha;

                        // could use R, G, or B -- arbitrary choice
                        if (srcPtr->R == 255) {
                            // do nothing -- leave dst alone
                        } else if (alpha == 255 || !blending) {
                            // copy it straight over
                            *dstPtr = brushPixel;
                        } else {
                            // do expensive blending
                            *dstPtr = UserBlendOps.NormalBlendOp.ApplyStatic (dstPixel, brushPixel);
                        }

                        ++dstPtr;
                        ++srcPtr;
                    }
                }
                //}

            }
        }

        private void RedrawText(bool showCursor, bool useToolLayer)
        {
            Cairo.ImageSurface surf;
            var invalidate_cursor = old_cursor_bounds;

            if (!useToolLayer)
                surf = PintaCore.Workspace.ActiveDocument.CurrentLayer.Surface;
            else {
                surf = PintaCore.Workspace.ActiveDocument.ToolLayer.Surface;
                surf.Clear ();
            }

            using (var g = new Cairo.Context (surf)) {
                g.Save ();

                // Show selection if on tool layer
                if (useToolLayer) {
                    // Selected Text
                    Cairo.Color c = new Cairo.Color (0.7, 0.8, 0.9, 0.5);
                    foreach (Rectangle rect in engine.SelectionRectangles)
                        g.FillRectangle (rect.ToCairoRectangle (), c);
                }
                g.AppendPath (PintaCore.Workspace.ActiveDocument.SelectionPath);
                g.FillRule = Cairo.FillRule.EvenOdd;
                g.Clip ();
                g.MoveTo (new Cairo.PointD (engine.Origin.X, engine.Origin.Y));
                g.Color = PintaCore.Palette.PrimaryColor;

                if (BackgroundFill)	{

                    using (var g2 = new Cairo.Context (surf)) {

                        g2.FillRectangle (engine.GetLayoutBounds ().ToCairoRectangle (),PintaCore.Palette.SecondaryColor);

                    }
            }

                if (FillText) {
                    Pango.CairoHelper.ShowLayout (g, engine.Layout);
            }

                if (FillText && StrokeText) {
                    g.Color = PintaCore.Palette.SecondaryColor;
                    g.LineWidth = OutlineWidth;

                    Pango.CairoHelper.LayoutPath (g, engine.Layout);
                    g.Stroke ();
                } else if (StrokeText) {
                    g.Color = PintaCore.Palette.PrimaryColor;
                    g.LineWidth = OutlineWidth;

                    Pango.CairoHelper.LayoutPath (g, engine.Layout);
                    g.Stroke ();
                }

                if (showCursor) {
                    var loc = engine.GetCursorLocation ();

                    g.Antialias = Cairo.Antialias.None;
                    g.DrawLine (new Cairo.PointD (loc.X, loc.Y), new Cairo.PointD (loc.X, loc.Y + loc.Height), new Cairo.Color (0, 0, 0, 1), 1);

                    loc.Inflate (2, 10);
                    old_cursor_bounds = loc;
                }

                g.Restore ();
            }

            Rectangle r = engine.GetLayoutBounds ();
            r.Inflate (10 + OutlineWidth, 10 + OutlineWidth);

            PintaCore.Workspace.Invalidate (old_bounds);
            PintaCore.Workspace.Invalidate (invalidate_cursor);
            PintaCore.Workspace.Invalidate (r);

            old_bounds = r;
        }

        /// <summary>
        /// Redraws the Text on the screen
        /// </summary>
        /// <remarks>
        /// assumes that the <b>font</b> and the <b>alignment</b> are already set
        /// </remarks>
        /// <param name="cursorOn"></param>
        private void RedrawText(bool cursorOn)
        {
            Cairo.ImageSurface surf = PintaCore.Layers.CurrentLayer.Surface;
            using (Cairo.Context context = new Cairo.Context (surf)) {
                if (this.ignoreRedraw > 0) {
                    return;
                }

                if (saved != null) {
                    saved.Draw (surf);
                    PintaCore.Workspace.Invalidate (saved.Region.Clipbox);
                    saved.Dispose ();
                    saved = null;
                }

                // Save the Space behind the lines
                Rectangle[] rects = new Rectangle[lines.Count + 1];
                Point[] localUls = new Point[lines.Count];

                // All Lines
                bool recalcSizes = false;

                if (this.sizes == null) {
                    recalcSizes = true;
                    this.sizes = new Size[lines.Count + 1];
                }

                if (recalcSizes) {
                    for (int i = 0; i < lines.Count; ++i) {
                        this.MeasureText (i);
                    }
                }

                for (int i = 0; i < lines.Count; ++i) {
                    Point upperLeft = GetUpperLeft (sizes[i], i);
                    localUls[i] = upperLeft;
                    Rectangle rect = new Rectangle (upperLeft, sizes[i]);
                    rects[i] = rect;
                }

                // The Cursor Line
                string cursorLine = ((string)lines[linePos]).Substring (0, textPos);
                Size cursorLineSize;
                Point cursorUL;
                Rectangle cursorRect;
                bool emptyCursorLineFlag;

                if (cursorLine.Length == 0) {
                    emptyCursorLineFlag = true;
                    Size fullLineSize = sizes[linePos];
                    cursorLineSize = new Size (2, FontHeight);
                    cursorUL = GetUpperLeft (fullLineSize, linePos);
                    cursorRect = new Rectangle (cursorUL, cursorLineSize);
                } else if (cursorLine.Length == ((string)lines[linePos]).Length) {
                    emptyCursorLineFlag = false;
                    cursorLineSize = sizes[linePos];
                    cursorUL = localUls[linePos];
                    cursorRect = new Rectangle (cursorUL, cursorLineSize);
                } else {
                    emptyCursorLineFlag = false;
                    cursorLineSize = StringSize (cursorLine);
                    cursorUL = localUls[linePos];
                    cursorRect = new Rectangle (cursorUL, cursorLineSize);
                }

                rects[lines.Count] = cursorRect;

                // Account for overhang on italic or fancy fonts
                int offset = FontHeight;
                for (int i = 0; i < rects.Length; ++i) {
                    rects[i].X -= offset;
                    rects[i].Width += 2 * offset;
                }

                // Set the saved region
                saved = new IrregularSurface (surf, Utility.InflateRectangles (rects, 3));

                // Draw the Lines
                this.uls = localUls;

                for (int i = 0; i < lines.Count; i++)
                    this.RenderText (surf, i);

                // Draw the Cursor
                if (cursorOn) {
                    using (Cairo.Context toolctx = new Cairo.Context (PintaCore.Layers.ToolLayer.Surface)) {
                        if (emptyCursorLineFlag) {
                            toolctx.FillRectangle (cursorRect.ToCairoRectangle (), PintaCore.Palette.PrimaryColor);
                        } else {
                            toolctx.DrawLine (new Cairo.PointD (cursorRect.Right, cursorRect.Top), new Cairo.PointD (cursorRect.Right, cursorRect.Bottom), PintaCore.Palette.PrimaryColor, 1);
                        }
                    }
                }
//.........这里部分代码省略.........