library/src/main/java/com/github/siyamed/shapeimageview/path/parser/PathParser.java
public static Path doPath(String s) {
        int n = s.length();
        ParserHelper ph = new ParserHelper(s);
        ph.skipWhitespace();
        Path p = new Path();
        float lastX = 0;
        float lastY = 0;
        float lastX1 = 0;
        float lastY1 = 0;
        float contourInitialX = 0;
        float contourInitialY = 0;
        RectF r = new RectF();
        char cmd = 'x';
        while (ph.pos < n) {
            char next = s.charAt(ph.pos);
            if (!Character.isDigit(next) && !(next == '.') && !(next == '-')) {
                cmd = next;
                ph.advance();
            } else if (cmd == 'M') { // implied command
                cmd = 'L';
            } else if (cmd == 'm') { // implied command
                cmd = 'l';
            } else { // implied command
                //ignore
            }
            p.computeBounds(r, true);
            // Log.d(TAG, "  " + cmd + " " + r);
            // Util.debug("* Commands remaining: '" + path + "'.");
            boolean wasCurve = false;
            switch (cmd) {
                case 'M':
                case 'm': {
                    float x = ph.nextFloat();
                    float y = ph.nextFloat();
                    if (cmd == 'm') {
                        p.rMoveTo(x, y);
                        lastX += x;
                        lastY += y;
                    } else {
                        p.moveTo(x, y);
                        lastX = x;
                        lastY = y;
                    }
                    contourInitialX = lastX;
                    contourInitialY = lastY;
                    break;
                }
                case 'Z':
                case 'z': {
                    /// p.lineTo(contourInitialX, contourInitialY);
                    p.close();
                    lastX = contourInitialX;
                    lastY = contourInitialY;
                    break;
                }
                case 'L':
                case 'l': {
                    float x = ph.nextFloat();
                    float y = ph.nextFloat();
                    if (cmd == 'l') {
                        p.rLineTo(x, y);
                        lastX += x;
                        lastY += y;
                    } else {
                        p.lineTo(x, y);
                        lastX = x;
                        lastY = y;
                    }
                    break;
                }
                case 'H':
                case 'h': {
                    float x = ph.nextFloat();
                    if (cmd == 'h') {
                        p.rLineTo(x, 0);
                        lastX += x;
                    } else {
                        p.lineTo(x, lastY);
                        lastX = x;
                    }
                    break;
                }
                case 'V':
                case 'v': {
                    float y = ph.nextFloat();
                    if (cmd == 'v') {
                        p.rLineTo(0, y);
                        lastY += y;
                    } else {
                        p.lineTo(lastX, y);
                        lastY = y;
                    }
                    break;
                }
                case 'C':
                case 'c': {
                    wasCurve = true;
                    float x1 = ph.nextFloat();
                    float y1 = ph.nextFloat();
                    float x2 = ph.nextFloat();
                    float y2 = ph.nextFloat();
                    float x = ph.nextFloat();
                    float y = ph.nextFloat();
                    if (cmd == 'c') {
                        x1 += lastX;
                        x2 += lastX;
                        x += lastX;
                        y1 += lastY;
                        y2 += lastY;
                        y += lastY;
                    }
                    p.cubicTo(x1, y1, x2, y2, x, y);
                    lastX1 = x2;
                    lastY1 = y2;
                    lastX = x;
                    lastY = y;
                    break;
                }
                case 'S':
                case 's': {
                    wasCurve = true;
                    float x2 = ph.nextFloat();
                    float y2 = ph.nextFloat();
                    float x = ph.nextFloat();
                    float y = ph.nextFloat();
                    if (cmd == 's') {
                        x2 += lastX;
                        x += lastX;
                        y2 += lastY;
                        y += lastY;
                    }
                    float x1 = 2 * lastX - lastX1;
                    float y1 = 2 * lastY - lastY1;
                    p.cubicTo(x1, y1, x2, y2, x, y);
                    lastX1 = x2;
                    lastY1 = y2;
                    lastX = x;
                    lastY = y;
                    break;
                }
                case 'A':
                case 'a': {
                    float rx = ph.nextFloat();
                    float ry = ph.nextFloat();
                    float theta = ph.nextFloat();
                    int largeArc = (int) ph.nextFloat();
                    int sweepArc = (int) ph.nextFloat();
                    float x = ph.nextFloat();
                    float y = ph.nextFloat();
                    if (cmd == 'a') {
                        x += lastX;
                        y += lastY;
                    }
                    drawArc(p, lastX, lastY, x, y, rx, ry, theta, largeArc == 1, sweepArc == 1);
                    lastX = x;
                    lastY = y;
                    break;
                }
                case 'T':
                case 't': {
                    wasCurve = true;
                    float x = ph.nextFloat();
                    float y = ph.nextFloat();
                    if (cmd == 't') {
                        x += lastX;
                        y += lastY;
                    }
                    float x1 = 2 * lastX - lastX1;
                    float y1 = 2 * lastY - lastY1;
                    p.cubicTo( lastX, lastY, x1, y1, x, y );
                    lastX = x;
                    lastY = y;
                    lastX1 = x1;
                    lastY1 = y1;
                    break;
                }
                case 'Q':
                case 'q': {
                    wasCurve = true;
                    float x1 = ph.nextFloat();
                    float y1 = ph.nextFloat();
                    float x = ph.nextFloat();
                    float y = ph.nextFloat();
                    if (cmd == 'q') {
                        x += lastX;
                        y += lastY;
                        x1 += lastX;
                        y1 += lastY;
                    }
                    p.cubicTo( lastX, lastY, x1, y1, x, y );
                    lastX1 = x1;
                    lastY1 = y1;
                    lastX = x;
                    lastY = y;
                    break;
                }
                default:
                    Log.w(TAG, "Invalid path command: " + cmd);
                    ph.advance();
            }
            if (!wasCurve) {
                lastX1 = lastX;
                lastY1 = lastY;
            }
            ph.skipWhitespace();
        }
        return p;
    }
public static Path doPath(String s) {
        int n = s.length();
        ParserHelper ph = new ParserHelper(s);
        ph.skipWhitespace();
        Path p = new Path();
        float lastX = 0;
        float lastY = 0;
        float lastX1 = 0;
        float lastY1 = 0;
        float contourInitialX = 0;
        float contourInitialY = 0;
        RectF r = new RectF();
        char cmd = 'x';
        while (ph.pos < n) {
            char next = s.charAt(ph.pos);
            if (!Character.isDigit(next) && !(next == '.') && !(next == '-')) {
                cmd = next;
                ph.advance();
            } else if (cmd == 'M') { // implied command
                cmd = 'L';
            } else if (cmd == 'm') { // implied command
                cmd = 'l';
            } else { // implied command
                //ignore
            }
            p.computeBounds(r, true);
            // Log.d(TAG, "  " + cmd + " " + r);
            // Util.debug("* Commands remaining: '" + path + "'.");
            boolean wasCurve = false;
            switch (cmd) {
                case 'M':
                case 'm': {
                    float x = ph.nextFloat();
                    float y = ph.nextFloat();
                    if (cmd == 'm') {
                        p.rMoveTo(x, y);
                        lastX += x;
                        lastY += y;
                    } else {
                        p.moveTo(x, y);
                        lastX = x;
                        lastY = y;
                    }
                    contourInitialX = lastX;
                    contourInitialY = lastY;
                    break;
                }
                case 'Z':
                case 'z': {
                    /// p.lineTo(contourInitialX, contourInitialY);
                    p.close();
                    lastX = contourInitialX;
                    lastY = contourInitialY;
                    break;
                }
                case 'L':
                case 'l': {
                    float x = ph.nextFloat();
                    float y = ph.nextFloat();
                    if (cmd == 'l') {
                        p.rLineTo(x, y);
                        lastX += x;
                        lastY += y;
                    } else {
                        p.lineTo(x, y);
                        lastX = x;
                        lastY = y;
                    }
                    break;
                }
                case 'H':
                case 'h': {
                    float x = ph.nextFloat();
                    if (cmd == 'h') {
                        p.rLineTo(x, 0);
                        lastX += x;
                    } else {
                        p.lineTo(x, lastY);
                        lastX = x;
                    }
                    break;
                }
                case 'V':
                case 'v': {
                    float y = ph.nextFloat();
                    if (cmd == 'v') {
                        p.rLineTo(0, y);
                        lastY += y;
                    } else {
                        p.lineTo(lastX, y);
                        lastY = y;
                    }
                    break;
                }
                case 'C':
                case 'c': {
                    wasCurve = true;
                    float x1 = ph.nextFloat();
                    float y1 = ph.nextFloat();
                    float x2 = ph.nextFloat();
                    float y2 = ph.nextFloat();
                    float x = ph.nextFloat();
                    float y = ph.nextFloat();
                    if (cmd == 'c') {
                        x1 += lastX;
                        x2 += lastX;
                        x += lastX;
                        y1 += lastY;
                        y2 += lastY;
                        y += lastY;
                    }
                    p.cubicTo(x1, y1, x2, y2, x, y);
                    lastX1 = x2;
                    lastY1 = y2;
                    lastX = x;
                    lastY = y;
                    break;
                }
                case 'S':
                case 's': {
                    wasCurve = true;
                    float x2 = ph.nextFloat();
                    float y2 = ph.nextFloat();
                    float x = ph.nextFloat();
                    float y = ph.nextFloat();
                    if (cmd == 's') {
                        x2 += lastX;
                        x += lastX;
                        y2 += lastY;
                        y += lastY;
                    }
                    float x1 = 2 * lastX - lastX1;
                    float y1 = 2 * lastY - lastY1;
                    p.cubicTo(x1, y1, x2, y2, x, y);
                    lastX1 = x2;
                    lastY1 = y2;
                    lastX = x;
                    lastY = y;
                    break;
                }
                case 'A':
                case 'a': {
                    float rx = ph.nextFloat();
                    float ry = ph.nextFloat();
                    float theta = ph.nextFloat();
                    int largeArc = (int) ph.nextFloat();
                    int sweepArc = (int) ph.nextFloat();
                    float x = ph.nextFloat();
                    float y = ph.nextFloat();
                    if (cmd == 'a') {
                        x += lastX;
                        y += lastY;
                    }
                    drawArc(p, lastX, lastY, x, y, rx, ry, theta, largeArc == 1, sweepArc == 1);
                    lastX = x;
                    lastY = y;
                    break;
                }
                case 'T':
                case 't': {
                    wasCurve = true;
                    float x = ph.nextFloat();
                    float y = ph.nextFloat();
                    if (cmd == 't') {
                        x += lastX;
                        y += lastY;
                    }
                    float x1 = 2 * lastX - lastX1;
                    float y1 = 2 * lastY - lastY1;
                    p.cubicTo( lastX, lastY, x1, y1, x, y );
                    lastX = x;
                    lastY = y;
                    lastX1 = x1;
                    lastY1 = y1;
                    break;
                }
                case 'Q':
                case 'q': {
                    wasCurve = true;
                    float x1 = ph.nextFloat();
                    float y1 = ph.nextFloat();
                    float x = ph.nextFloat();
                    float y = ph.nextFloat();
                    if (cmd == 'q') {
                        x += lastX;
                        y += lastY;
                        x1 += lastX;
                        y1 += lastY;
                    }
                    p.cubicTo( lastX, lastY, x1, y1, x, y );
                    lastX1 = x1;
                    lastY1 = y1;
                    lastX = x;
                    lastY = y;
                    break;
                }
                default:
                    Log.w(TAG, "Invalid path command: " + cmd);
                    ph.advance();
            }
            if (!wasCurve) {
                lastX1 = lastX;
                lastY1 = lastY;
            }
            ph.skipWhitespace();
        }
        return p;
    }
/*
This is where the hard-to-parse paths are handled.
Uppercase rules are absolute positions, lowercase are relative.
Types of path rules:
<p/>
<ol>
<li>M/m - (x y)+ - Move to (without drawing)
<li>Z/z - (no params) - Close path (back to starting point)
<li>L/l - (x y)+ - Line to
<li>H/h - x+ - Horizontal ine to
<li>V/v - y+ - Vertical line to
<li>C/c - (x1 y1 x2 y2 x y)+ - Cubic bezier to
<li>S/s - (x2 y2 x y)+ - Smooth cubic bezier to (shorthand that assumes the x2, y2 from previous C/S is the x1, y1 of this bezier)
<li>Q/q - (x1 y1 x y)+ - Quadratic bezier to
<li>T/t - (x y)+ - Smooth quadratic bezier to (assumes previous control point is "reflection" of last one w.r.t. to current point)
</ol>
<p/>
Numbers are separate by whitespace, comma or nothing at all (!) if they are self-delimiting, (ie. begin with a - sign)