Initial support for turning Skia draws into a JSON document and vice versa.

tools/json/SkJSONCanvas.cpp

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkJSONCanvas.h"
+#include "SkPath.h"
+#include "SkRRect.h"
+#include "stdio.h"
+#include "stdlib.h"
+
+SkJSONCanvas::SkJSONCanvas(int width, int height, SkWStream& out) 
+        : INHERITED(width, height)
+        , fOut(out)
+        , fFirstCommand(true) {
+        fOut.writeText("{\"" SKJSONCANVAS_VERSION "\":1, \"" SKJSONCANVAS_COMMANDS 
+                   "\":[");
+}
+
+void SkJSONCanvas::finish() {
+        fOut.writeText("]}");
+}
+
+void SkJSONCanvas::writef(const char* format, ...) {
+    va_list args;
+    va_start(args, format);
+    SkString s;
+    s.appendVAList(format, args);
+    fOut.writeText(s.c_str());
+}
+
+void SkJSONCanvas::open(const char* name) {
+        if (fFirstCommand) {
+                fFirstCommand = false;
+        }
+        else {
+                fOut.writeText(",");
+        }
+        this->writef("{\"" SKJSONCANVAS_COMMAND "\":\"%s\"", name);
+}
+
+void SkJSONCanvas::close() {
+        fOut.writeText("}");
+}
+
+void SkJSONCanvas::writeString(const char* name, const char* text) {
+    this->writeString(name, text, strlen(text));
+}
+
+void SkJSONCanvas::writeString(const char* name, const void* text, size_t length) {
+        // TODO: escaping
+        this->writef(",\"%s\":\"", name);
+        fOut.write(text, length);
+        fOut.writeText("\"");
+}
+
+void SkJSONCanvas::writePoint(const char* name, const SkPoint& point) {
+        this->writef(",\"%s\":[%f, %f]", name, point.x(), point.y());
+}
+
+void SkJSONCanvas::writeRect(const char* name, const SkRect& rect) {
+        this->writef(",\"%s\":[%f, %f, %f, %f]", name, rect.left(), rect.top(), rect.right(), 
+                                 rect.bottom());
+}
+
+void SkJSONCanvas::writeRRect(const char* name, const SkRRect& rrect) {
+        SkRect rect = rrect.rect();
+        SkVector corner1 = rrect.radii(SkRRect::kUpperLeft_Corner);
+        SkVector corner2 = rrect.radii(SkRRect::kUpperRight_Corner);
+        SkVector corner3 = rrect.radii(SkRRect::kLowerLeft_Corner);
+        SkVector corner4 = rrect.radii(SkRRect::kLowerRight_Corner);
+        this->writef(",\"%s\":[[%f, %f, %f, %f],[%f, %f],[%f, %f],[%f, %f],[%f, %f]]", name, 
+                                 rect.left(), rect.top(), rect.right(), rect.bottom(), corner1.x(), corner1.y(), 
+                                 corner2.x(), corner2.y(), corner3.x(), corner3.y(), corner4.x(), corner4.y());
+}
+
+void SkJSONCanvas::writePath(const char* name, const SkPath& path) {
+        SkString text("[");
+    SkPath::Iter iter(path, false);
+    SkPoint pts[4];
+    bool first = true;
+    SkPath::Verb verb;
+    while ((verb = iter.next(pts)) != SkPath::kDone_Verb) {
+        if (first) {
+                first = false;
+        }
+        else {
+                        text.append(",");
+        }
+        switch (verb) {
+            case SkPath::kLine_Verb:
+                text.appendf("{\"" SKJSONCANVAS_VERB_LINE "\":[%f,%f]}", pts[1].x(), pts[1].y());
+                break;
+            case SkPath::kQuad_Verb:
+                text.appendf("{\"" SKJSONCANVAS_VERB_QUAD "\":[[%f,%f],[%f,%f]]}", pts[1].x(), 
+                             pts[1].y(), pts[2].x(), pts[2].y());
+                break;
+            case SkPath::kCubic_Verb:
+                text.appendf("{\"" SKJSONCANVAS_VERB_CUBIC "\":[[%f,%f],[%f,%f],[%f,%f]]}", 
+                             pts[1].x(), pts[1].y(), pts[2].x(), pts[2].y(), pts[3].x(), 
+                             pts[3].y());
+                break;
+            case SkPath::kConic_Verb:
+                text.appendf("{\"" SKJSONCANVAS_VERB_CONIC "\":[[%f,%f],[%f,%f],%f]}", pts[1].x(), 
+                             pts[1].y(), pts[2].x(), pts[2].y(), iter.conicWeight());
+                break;
+            case SkPath::kMove_Verb:
+                text.appendf("{\"" SKJSONCANVAS_VERB_MOVE "\":[%f,%f]}", pts[0].x(), pts[0].y());
+                break;
+            case SkPath::kClose_Verb:
+                text.appendf("\"" SKJSONCANVAS_VERB_CLOSE "\"");
+                break;
+            case SkPath::kDone_Verb:
+                break;
+        }
+    }
+    text.appendf("]");
+        this->writef(",\"" SKJSONCANVAS_ATTRIBUTE_PATH "\":%s", text.c_str());
+}
+
+void SkJSONCanvas::writeRegion(const char* name, const SkRegion& region) {
+        this->writef(",\"%s\":\"<unimplemented>\"", name);
+}
+
+void SkJSONCanvas::writePaint(const SkPaint& paint) {
+        this->writef(",\"" SKJSONCANVAS_ATTRIBUTE_PAINT "\":{");
+        SkColor color = paint.getColor();
+        bool first = true;
+        if (color != SK_ColorBLACK) {
+                this->writef("\"" SKJSONCANVAS_ATTRIBUTE_COLOR "\":[%d,%d,%d,%d]", SkColorGetA(color), 
+                     SkColorGetR(color), SkColorGetG(color), SkColorGetB(color));
+                first = false;
+        }
+    SkPaint::Style style = paint.getStyle();
+    if (style != SkPaint::kFill_Style) {
+        if (first) {
+            first = false;
+        }
+        else {
+            fOut.writeText(",");
+        }
+        switch (style) {
+            case SkPaint::kStroke_Style:        
+                fOut.writeText("\"" SKJSONCANVAS_ATTRIBUTE_STYLE "\":\""
+                               SKJSONCANVAS_STYLE_STROKE "\"");
+                break;
+            case SkPaint::kStrokeAndFill_Style: 
+                fOut.writeText("\"" SKJSONCANVAS_ATTRIBUTE_STYLE "\":\""
+                               SKJSONCANVAS_STYLE_STROKEANDFILL "\""); 
+                break;
+            default: SkASSERT(false);
+        }
+    }
+    SkScalar strokeWidth = paint.getStrokeWidth();
+    if (strokeWidth != 0.0f) {
+        if (first) {
+            first = false;
+        }
+        else {
+            fOut.writeText(",");
+        }
+        this->writef("\"" SKJSONCANVAS_ATTRIBUTE_STROKEWIDTH "\":%f", strokeWidth);
+    }
+    if (paint.isAntiAlias()) {
+        if (first) {
+            first = false;
+        }
+        else {
+            fOut.writeText(",");
+        }
+        fOut.writeText("\"" SKJSONCANVAS_ATTRIBUTE_ANTIALIAS "\":true");
+    }
+        fOut.writeText("}");
+}
+
+void SkJSONCanvas::writeMatrix(const char* name, const SkMatrix& matrix) {
+        this->writef(",\"%s\":[[%f,%f,%f],[%f,%f,%f],[%f,%f,%f]]", name,
+                                 matrix[0], matrix[1], matrix[2],
+                                 matrix[3], matrix[4], matrix[5],
+                                 matrix[6], matrix[7], matrix[8]);
+}
+
+void SkJSONCanvas::writeRegionOp(const char* name, SkRegion::Op op) {
+        this->writef(",\"%s\":\"", name);
+        switch (op) {
+        case SkRegion::kDifference_Op:
+            fOut.writeText(SKJSONCANVAS_REGIONOP_DIFFERENCE);
+            break;
+        case SkRegion::kIntersect_Op:
+            fOut.writeText(SKJSONCANVAS_REGIONOP_INTERSECT);
+            break;
+        case SkRegion::kUnion_Op:
+            fOut.writeText(SKJSONCANVAS_REGIONOP_UNION);
+            break;
+        case SkRegion::kXOR_Op:
+            fOut.writeText(SKJSONCANVAS_REGIONOP_XOR);
+            break;
+        case SkRegion::kReverseDifference_Op:
+            fOut.writeText(SKJSONCANVAS_REGIONOP_REVERSE_DIFFERENCE);
+            break;
+        case SkRegion::kReplace_Op:
+            fOut.writeText(SKJSONCANVAS_REGIONOP_REPLACE);
+            break;
+        default:
+            SkASSERT(false);
+    };
+    fOut.writeText("\"");
+}
+
+void SkJSONCanvas::writeEdgeStyle(const char* name, SkCanvas::ClipEdgeStyle edgeStyle) {
+        this->writef(",\"%s\":\"", name);
+        switch (edgeStyle) {
+        case SkCanvas::kHard_ClipEdgeStyle: fOut.writeText(SKJSONCANVAS_EDGESTYLE_HARD); break;
+        case SkCanvas::kSoft_ClipEdgeStyle: fOut.writeText(SKJSONCANVAS_EDGESTYLE_SOFT); break;
+        default:                            SkASSERT(false);
+    };
+    fOut.writeText("\"");
+}
+
+void SkJSONCanvas::writePointMode(const char* name, SkCanvas::PointMode mode) {
+    this->writef(",\"%s\":\"", name);
+    switch (mode) {
+        case SkCanvas::kPoints_PointMode:  fOut.writeText(SKJSONCANVAS_POINTMODE_POINTS);  break;
+        case SkCanvas::kLines_PointMode:   fOut.writeText(SKJSONCANVAS_POINTMODE_LINES);   break;
+        case SkCanvas::kPolygon_PointMode: fOut.writeText(SKJSONCANVAS_POINTMODE_POLYGON); break;
+        default:                           SkASSERT(false);
+    };
+    fOut.writeText("\"");
+}
+
+void SkJSONCanvas::updateMatrix() {
+        const SkMatrix& matrix = this->getTotalMatrix();
+        if (matrix != fLastMatrix) {
+                this->open(SKJSONCANVAS_COMMAND_MATRIX);
+                this->writeMatrix(SKJSONCANVAS_ATTRIBUTE_MATRIX, matrix);
+                fLastMatrix = matrix;
+                this->close();
+        }
+}
+
+void SkJSONCanvas::onDrawPaint(const SkPaint& paint) {
+        this->open(SKJSONCANVAS_COMMAND_PAINT);
+        this->writePaint(paint);
+        this->close();
+}
+
+void SkJSONCanvas::onDrawRect(const SkRect& rect, const SkPaint& paint) {
+        this->updateMatrix();
+        this->open(SKJSONCANVAS_COMMAND_RECT);
+        this->writeRect(SKJSONCANVAS_ATTRIBUTE_COORDS, rect);
+        this->writePaint(paint);
+        this->close();
+}
+
+void SkJSONCanvas::onDrawOval(const SkRect& rect, const SkPaint& paint) {
+        this->updateMatrix();
+        this->open(SKJSONCANVAS_COMMAND_OVAL);
+        this->writeRect(SKJSONCANVAS_ATTRIBUTE_COORDS, rect);
+        this->writePaint(paint);
+        this->close();
+}
+
+void SkJSONCanvas::onDrawRRect(const SkRRect& rrect, const SkPaint& paint) {
+        this->updateMatrix();
+        this->open(SKJSONCANVAS_COMMAND_RRECT);
+        this->writeRRect(SKJSONCANVAS_ATTRIBUTE_COORDS, rrect);
+        this->writePaint(paint);
+        this->close();}
+
+void SkJSONCanvas::onDrawDRRect(const SkRRect& outer, const SkRRect& inner, const SkPaint& paint) {
+    this->updateMatrix();
+    this->open(SKJSONCANVAS_COMMAND_DRRECT);
+    this->writeRRect(SKJSONCANVAS_ATTRIBUTE_OUTER, outer);
+    this->writeRRect(SKJSONCANVAS_ATTRIBUTE_INNER, inner);
+    this->writePaint(paint);
+    this->close();
+}
+
+void SkJSONCanvas::onDrawPoints(SkCanvas::PointMode mode, size_t count, const SkPoint pts[], 
+                                                                const SkPaint& paint) {
+    this->updateMatrix();
+    this->open(SKJSONCANVAS_COMMAND_POINTS);
+    this->writePointMode(SKJSONCANVAS_ATTRIBUTE_MODE, mode);
+    fOut.writeText(",\"" SKJSONCANVAS_ATTRIBUTE_POINTS "\":[");
+    for (size_t i = 0; i < count; i++) {
+        if (i != 0) {
+            fOut.writeText(",");
+        }
+        this->writef("[%f,%f]", pts[i].x(), pts[i].y());
+    }
+    fOut.writeText("]");
+    this->writePaint(paint);
+    this->close();
+}
+
+void SkJSONCanvas::onDrawVertices(SkCanvas::VertexMode, int vertexCount, const SkPoint vertices[],
+                                  const SkPoint texs[], const SkColor colors[], SkXfermode*,
+                                  const uint16_t indices[], int indexCount, const SkPaint&) {
+    SkDebugf("unsupported: drawVertices\n");
+}
+
+void SkJSONCanvas::onDrawAtlas(const SkImage*, const SkRSXform[], const SkRect[], const SkColor[],
+                               int count, SkXfermode::Mode, const SkRect* cull, const SkPaint*) {
+    SkDebugf("unsupported: drawAtlas\n");
+}
+
+void SkJSONCanvas::onDrawPath(const SkPath& path, const SkPaint& paint) {
+        this->updateMatrix();
+        this->open(SKJSONCANVAS_COMMAND_PATH);
+        this->writePath(SKJSONCANVAS_ATTRIBUTE_PATH, path);
+        this->writePaint(paint);
+        this->close();}
+
+void SkJSONCanvas::onDrawImage(const SkImage*, SkScalar dx, SkScalar dy, const SkPaint*) {
+    SkDebugf("unsupported: drawImage\n");
+}
+
+void SkJSONCanvas::onDrawImageRect(const SkImage*, const SkRect*, const SkRect&, const SkPaint*,
+                                   SkCanvas::SrcRectConstraint) {
+    SkDebugf("unsupported: drawImageRect\n");
+}
+
+void SkJSONCanvas::onDrawImageNine(const SkImage*, const SkIRect& center, const SkRect& dst,
+                                   const SkPaint*) {
+    SkDebugf("unsupported: drawImageNine\n");
+}
+
+void SkJSONCanvas::onDrawBitmap(const SkBitmap&, SkScalar dx, SkScalar dy, const SkPaint*) {
+    SkDebugf("unsupported: drawBitmap\n");
+}
+
+void SkJSONCanvas::onDrawBitmapRect(const SkBitmap&, const SkRect*, const SkRect&, const SkPaint*,
+                                    SkCanvas::SrcRectConstraint) {
+    SkDebugf("unsupported: drawBitmapRect\n");
+}
+
+void SkJSONCanvas::onDrawBitmapNine(const SkBitmap&, const SkIRect& center, const SkRect& dst,
+                                    const SkPaint*) {
+    SkDebugf("unsupported: drawBitmapNine\n");
+}
+
+void SkJSONCanvas::onDrawText(const void* text, size_t byteLength, SkScalar x,
+                              SkScalar y, const SkPaint& paint) {
+    this->updateMatrix();
+    this->open(SKJSONCANVAS_COMMAND_TEXT);
+    this->writeString(SKJSONCANVAS_ATTRIBUTE_TEXT, text, byteLength);
+    this->writePoint(SKJSONCANVAS_ATTRIBUTE_COORDS, { x, y });
+    this->writePaint(paint);
+    this->close();
+}
+
+void SkJSONCanvas::onDrawPosText(const void* text, size_t byteLength,
+                                 const SkPoint pos[], const SkPaint& paint) {
+    SkDebugf("unsupported: drawPosText\n");
+}
+
+void SkJSONCanvas::onDrawPosTextH(const void* text, size_t byteLength,
+                                  const SkScalar xpos[], SkScalar constY,
+                                  const SkPaint& paint) {
+    SkDebugf("unsupported: drawPosTextH\n");
+}
+
+void SkJSONCanvas::onDrawTextOnPath(const void* text, size_t byteLength,
+                                    const SkPath& path, const SkMatrix* matrix,
+                                    const SkPaint& paint) {
+    SkDebugf("unsupported: drawTextOnPath\n");
+}
+
+void SkJSONCanvas::onDrawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y,
+                                  const SkPaint& paint) {
+    SkDebugf("unsupported: drawTextBlob\n");
+}
+
+void SkJSONCanvas::onDrawPatch(const SkPoint cubics[12], const SkColor colors[4],
+                               const SkPoint texCoords[4], SkXfermode* xmode, 
+                               const SkPaint& paint) {
+    SkDebugf("unsupported: drawPatch\n");
+}
+
+void SkJSONCanvas::onDrawDrawable(SkDrawable*, const SkMatrix*) {
+    SkDebugf("unsupported: drawDrawable\n");
+}
+
+void SkJSONCanvas::onClipRect(const SkRect& rect, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
+        this->updateMatrix();
+        this->open(SKJSONCANVAS_COMMAND_CLIPRECT);
+        this->writeRect(SKJSONCANVAS_ATTRIBUTE_COORDS, rect);
+        this->writeRegionOp(SKJSONCANVAS_ATTRIBUTE_REGIONOP, op);
+        this->writeEdgeStyle(SKJSONCANVAS_ATTRIBUTE_EDGESTYLE, edgeStyle);
+        this->close();
+}
+
+void SkJSONCanvas::onClipRRect(const SkRRect& rrect, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
+        this->updateMatrix();
+        this->open(SKJSONCANVAS_COMMAND_CLIPRRECT);
+        this->writeRRect(SKJSONCANVAS_ATTRIBUTE_COORDS, rrect);
+        this->writeRegionOp(SKJSONCANVAS_ATTRIBUTE_REGIONOP, op);
+        this->writeEdgeStyle(SKJSONCANVAS_ATTRIBUTE_EDGESTYLE, edgeStyle);
+        this->close();
+}
+
+void SkJSONCanvas::onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
+        updateMatrix();
+        this->open(SKJSONCANVAS_COMMAND_CLIPPATH);
+        this->writePath(SKJSONCANVAS_ATTRIBUTE_PATH, path);
+        this->writeRegionOp(SKJSONCANVAS_ATTRIBUTE_REGIONOP, op);
+        this->writeEdgeStyle(SKJSONCANVAS_ATTRIBUTE_EDGESTYLE, edgeStyle);
+        this->close();
+}
+
+void SkJSONCanvas::onClipRegion(const SkRegion& deviceRgn, SkRegion::Op op) {
+        this->open(SKJSONCANVAS_COMMAND_CLIPREGION);
+        this->writeRegion(SKJSONCANVAS_ATTRIBUTE_DEVICEREGION, deviceRgn);
+        this->writeRegionOp(SKJSONCANVAS_ATTRIBUTE_REGIONOP, op);
+        this->close();
+}
+
+void SkJSONCanvas::willSave() {
+        this->open(SKJSONCANVAS_COMMAND_SAVE);
+        this->close();
+}
+
+void SkJSONCanvas::willRestore() {
+        this->open(SKJSONCANVAS_COMMAND_RESTORE);
+        this->close();
+}