How to draw hexagons in android?

Question

I used the hexagon code in this tutorial and created the createHex class (should I post the code?). The linked webpage used the following code to actually draw hexagons using math in createHex:

@Override public void paint(Graphics g){ for(int j = 0; int j < BOARD_HEIGHT; j++){ for(int i = 0; i < BOARD_HEIGHT; I++){ mCellMetrics.setCellIndex(i, j); if(mCells[j][i] != 0){ mCellMetrics.computeCorners(mCornersX, mCornersY); g.setColor((mCells[j][i] == L_ON) ? COLOR.ORANGE):COLOR.GRAY; g.fillPolygon(mCornersX, mCornersY, NUM_HEX_CORNERS); g.setColor(COLOR.BLACK) g.drawPolygon(mCornersX, mCornersY, NUM_HEX_CORNERS); } } } } 

The problem I am facing is that Android does not have a Graphics class that contains all the necessary methods. I spent about an hour and a half fishing around the android documentation, and the closest I found was the Path class, but it is not the methods I need. I want to use the hexagon code in the related article at the top, but I cannot find the equivalent of the graphics class. If there is no equivalent, can someone show me how to get the results that I want to use related code?

My question is: how can I port the code in a related article to android?

EDIT:

I decided that this could be useful to others (and potential respondents) if I included a hexagon code that calculates sides and something else like a hexagon, so here is createHex.java:

  package com.rush; /** * Uniform hexagonal grid cell metrics utility class. */ public class HexGridCell { private static final int[] NEIGHBORS_DI = { 0, 1, 1, 0, -1, -1 }; private static final int[][] NEIGHBORS_DJ = { { -1, -1, 0, 1, 0, -1 }, { -1, 0, 1, 1, 1, 0 } }; private final int[] CORNERS_DX; // array of horizontal offsets of the cell corners private final int[] CORNERS_DY; // array of vertical offsets of the cell corners private final int SIDE; private int mX = 0; // cell left coordinate private int mY = 0; // cell top coordinate private int mI = 0; // cell horizontal grid coordinate private int mJ = 0; // cell vertical grid coordinate /** * Cell radius (distance from center to one of the corners) */ public final int RADIUS; /** * Cell height */ public final int HEIGHT; /** * Cell width */ public final int WIDTH; public static final int NUM_NEIGHBORS = 6; /** * @param radius Cell radius (distance from the center to one of the corners) */ public HexGridCell(int radius) { RADIUS = radius; WIDTH = radius * 2; HEIGHT = (int) (((float) radius) * Math.sqrt(3)); SIDE = radius * 3 / 2; int cdx[] = { RADIUS / 2, SIDE, WIDTH, SIDE, RADIUS / 2, 0 }; CORNERS_DX = cdx; int cdy[] = { 0, 0, HEIGHT / 2, HEIGHT, HEIGHT, HEIGHT / 2 }; CORNERS_DY = cdy; } /** * @return X coordinate of the cell top left corner. */ public int getLeft() { return mX; } /** * @return Y coordinate of the cell top left corner. */ public int getTop() { return mY; } /** * @return X coordinate of the cell center */ public int getCenterX() { return mX + RADIUS; } /** * @return Y coordinate of the cell center */ public int getCenterY() { return mY + HEIGHT / 2; } /** * @return Horizontal grid coordinate for the cell. */ public int getIndexI() { return mI; } /** * @return Vertical grid coordinate for the cell. */ public int getIndexJ() { return mJ; } /** * @return Horizontal grid coordinate for the given neighbor. */ public int getNeighborI(int neighborIdx) { return mI + NEIGHBORS_DI[neighborIdx]; } /** * @return Vertical grid coordinate for the given neighbor. */ public int getNeighborJ(int neighborIdx) { return mJ + NEIGHBORS_DJ[mI % 2][neighborIdx]; } /** * Computes X and Y coordinates for all of the cell 6 corners, clockwise, * starting from the top left. * * @param cornersX Array to fill in with X coordinates of the cell corners * @param cornersX Array to fill in with Y coordinates of the cell corners */ public void computeCorners(int[] cornersX, int[] cornersY) { for (int k = 0; k < NUM_NEIGHBORS; k++) { cornersX[k] = mX + CORNERS_DX[k]; cornersY[k] = mY + CORNERS_DY[k]; } } /** * Sets the cell horizontal and vertical grid coordinates. */ public void setCellIndex(int i, int j) { mI = i; mJ = j; mX = i * SIDE; mY = HEIGHT * (2 * j + (i % 2)) / 2; } /** * Sets the cell as corresponding to some point inside it (can be used for * eg mouse picking). */ public void setCellByPoint(int x, int y) { int ci = (int)Math.floor((float)x/(float)SIDE); int cx = x - SIDE*ci; int ty = y - (ci % 2) * HEIGHT / 2; int cj = (int)Math.floor((float)ty/(float)HEIGHT); int cy = ty - HEIGHT*cj; if (cx > Math.abs(RADIUS / 2 - RADIUS * cy / HEIGHT)) { setCellIndex(ci, cj); } else { setCellIndex(ci - 1, cj + (ci % 2) - ((cy < HEIGHT / 2) ? 1 : 0)); } } } 

For an explanation of how the code works, see the related article.

Answer 1

Try the following:

 import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Path; import android.graphics.Region; import android.util.AttributeSet; import android.view.View; public class HexagonMaskView extends View { private Path hexagonPath; private Path hexagonBorderPath; private float radius; private float width, height; private int maskColor; public HexagonMaskView(Context context) { super(context); init(); } public HexagonMaskView(Context context, AttributeSet attrs) { super(context, attrs); init(); } public HexagonMaskView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(); } private void init() { hexagonPath = new Path(); hexagonBorderPath = new Path(); maskColor = 0xFF01FF77; } public void setRadius(float r) { this.radius = r; calculatePath(); } public void setMaskColor(int color) { this.maskColor = color; invalidate(); } private void calculatePath() { float triangleHeight = (float) (Math.sqrt(3) * radius / 2); float centerX = width/2; float centerY = height/2; hexagonPath.moveTo(centerX, centerY + radius); hexagonPath.lineTo(centerX - triangleHeight, centerY + radius/2); hexagonPath.lineTo(centerX - triangleHeight, centerY - radius/2); hexagonPath.lineTo(centerX, centerY - radius); hexagonPath.lineTo(centerX + triangleHeight, centerY - radius/2); hexagonPath.lineTo(centerX + triangleHeight, centerY + radius/2); hexagonPath.moveTo(centerX, centerY + radius); float radiusBorder = radius - 5; float triangleBorderHeight = (float) (Math.sqrt(3) * radiusBorder / 2); hexagonBorderPath.moveTo(centerX, centerY + radiusBorder); hexagonBorderPath.lineTo(centerX - triangleBorderHeight, centerY + radiusBorder/2); hexagonBorderPath.lineTo(centerX - triangleBorderHeight, centerY - radiusBorder/2); hexagonBorderPath.lineTo(centerX, centerY - radiusBorder); hexagonBorderPath.lineTo(centerX + triangleBorderHeight, centerY - radiusBorder/2); hexagonBorderPath.lineTo(centerX + triangleBorderHeight, centerY + radiusBorder/2); hexagonBorderPath.moveTo(centerX, centerY + radiusBorder); invalidate(); } @Override public void onDraw(Canvas c){ super.onDraw(c); c.clipPath(hexagonBorderPath, Region.Op.DIFFERENCE); c.drawColor(Color.WHITE); c.save(); c.clipPath(hexagonPath, Region.Op.DIFFERENCE); c.drawColor(maskColor); c.save(); } // getting the view size and default radius @Override public void onMeasure(int widthMeasureSpec, int heightMeasureSpec){ super.onMeasure(widthMeasureSpec, heightMeasureSpec); width = MeasureSpec.getSize(widthMeasureSpec); height = MeasureSpec.getSize(heightMeasureSpec); radius = height / 2 - 10; calculatePath(); } } 

Answer 2

Try this or download a demo .

 public static Bitmap getHexagonalCroppedBitmap(Bitmap bitmap, int radius) { Bitmap finalBitmap; if (bitmap.getWidth() != radius || bitmap.getHeight() != radius) finalBitmap = Bitmap.createScaledBitmap(bitmap, radius, radius, false); else finalBitmap = bitmap; Bitmap output = Bitmap.createBitmap(finalBitmap.getWidth(), finalBitmap.getHeight(), Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(output); Paint paint = new Paint(); final Rect rect = new Rect(0, 0, finalBitmap.getWidth(), finalBitmap.getHeight()); Point point1_draw = new Point(75, 0); Point point2_draw = new Point(0, 50); Point point3_draw = new Point(0, 100); Point point4_draw = new Point(75, 150); Point point5_draw = new Point(150, 100); Point point6_draw = new Point(150, 50); Path path = new Path(); path.moveTo(point1_draw.x, point1_draw.y); path.lineTo(point2_draw.x, point2_draw.y); path.lineTo(point3_draw.x, point3_draw.y); path.lineTo(point4_draw.x, point4_draw.y); path.lineTo(point5_draw.x, point5_draw.y); path.lineTo(point6_draw.x, point6_draw.y); path.close(); canvas.drawARGB(0, 0, 0, 0); paint.setColor(Color.parseColor("#BAB399")); canvas.drawPath(path, paint); paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN)); canvas.drawBitmap(finalBitmap, rect, rect, paint); return output; } 

pass the image to be cropped into a hexagon as a bitmap for this function

 Bitmap myhexagon = getHexagonalCroppedBitmap(Myimage, yourHexagonalRadius);