I'm working with ARCore in Android Studio using java and am trying to implement ray intersection with an object.
I started with Google's provided sample (as found here: https://developers.google.com/ar/develop/java/getting-started).
Upon touching the screen, a ray gets projected and when this ray touches a Plane, a PlaneAttachment (with an Anchor/a Pose) is created in the intersection point.
I would then like to put a 3D triangle in the world attached to this Pose.
At the moment I create my Triangle based on the Pose's translation, like this:
In HelloArActivity, during onDrawFrame(...)
//Code from sample, determining the hits on planes
MotionEvent tap = mQueuedSingleTaps.poll();
if (tap != null && frame.getTrackingState() == TrackingState.TRACKING) {
for (HitResult hit : frame.hitTest(tap)) {
// Check if any plane was hit, and if it was hit inside the plane polygon.
if (hit instanceof PlaneHitResult && ((PlaneHitResult) hit).isHitInPolygon()) {
mTouches.add(new PlaneAttachment(
((PlaneHitResult) hit).getPlane(),
mSession.addAnchor(hit.getHitPose())));
//creating a triangle in the world
Pose hitPose = hit.getHitPose();
float[] poseCoords = new float[3];
hitPose.getTranslation(poseCoords, 0);
mTriangle = new Triangle(poseCoords);
}
}
}
Note: I am aware that the triangle's coordinates should be updated every time the Pose's coordinates get updated. I left this out as it is not part of my issue.
Triangle class
public class Triangle {
public float[] v0;
public float[] v1;
public float[] v2;
//create triangle around a given coordinate
public Triangle(float[] poseCoords){
float x = poseCoords[0], y = poseCoords[1], z = poseCoords[2];
this.v0 = new float[]{x+0.0001f, y-0.0001f, z};
this.v1 = new float[]{x, y+ 0.0001f, z-0.0001f};
this.v2 = new float[]{x-0.0001f, y, z+ 0.0001f};
}
After this, upon tapping the screen again I create a ray projected from the tapped (x,y) part of the screen, using Ian M his code sample provided in the answer to this question: how to check ray intersection with object in ARCore
Ray Creation, in HelloArActivity
/**
* Returns a world coordinate frame ray for a screen point. The ray is
* defined using a 6-element float array containing the head location
* followed by a normalized direction vector.
*/
float[] screenPointToWorldRay(float xPx, float yPx, Frame frame) {
float[] points = new float[12]; // {clip query, camera query, camera origin}
// Set up the clip-space coordinates of our query point
// +x is right:
points[0] = 2.0f * xPx / mSurfaceView.getMeasuredWidth() - 1.0f;
// +y is up (android UI Y is down):
points[1] = 1.0f - 2.0f * yPx / mSurfaceView.getMeasuredHeight();
points[2] = 1.0f; // +z is forwards (remember clip, not camera)
points[3] = 1.0f; // w (homogenous coordinates)
float[] matrices = new float[32]; // {proj, inverse proj}
// If you'll be calling this several times per frame factor out
// the next two lines to run when Frame.isDisplayRotationChanged().
mSession.getProjectionMatrix(matrices, 0, 1.0f, 100.0f);
Matrix.invertM(matrices, 16, matrices, 0);
// Transform clip-space point to camera-space.
Matrix.multiplyMV(points, 4, matrices, 16, points, 0);
// points[4,5,6] is now a camera-space vector. Transform to world space to get a point
// along the ray.
float[] out = new float[6];
frame.getPose().transformPoint(points, 4, out, 3);
// use points[8,9,10] as a zero vector to get the ray head position in world space.
frame.getPose().transformPoint(points, 8, out, 0);
// normalize the direction vector:
float dx = out[3] - out[0];
float dy = out[4] - out[1];
float dz = out[5] - out[2];
float scale = 1.0f / (float) Math.sqrt(dx*dx + dy*dy + dz*dz);
out[3] = dx * scale;
out[4] = dy * scale;
out[5] = dz * scale;
return out;
}
The result of this however is that, no matter where I tap the screen, it always counts as a hit (regardless of how much distance I add between the points, in Triangle's constructor).
I suspect this has to do with how a Pose is located in the world, and using the Pose's translation coordinates as a reference point for my triangle is not the way to go, so I'm looking for the correct way to do this, but any remarks regarding other parts of my method are welcome!
Also I have tested my method for ray-triangle intersection and I don't think it is the problem, but I'll include it here for completeness:
public Point3f intersectRayTriangle(CustomRay R, Triangle T) {
Point3f I = new Point3f();
Vector3f u, v, n;
Vector3f dir, w0, w;
float r, a, b;
u = new Vector3f(T.V1);
u.sub(new Point3f(T.V0));
v = new Vector3f(T.V2);
v.sub(new Point3f(T.V0));
n = new Vector3f(); // cross product
n.cross(u, v);
if (n.length() == 0) {
return null;
}
dir = new Vector3f(R.direction);
w0 = new Vector3f(R.origin);
w0.sub(new Point3f(T.V0));
a = -(new Vector3f(n).dot(w0));
b = new Vector3f(n).dot(dir);
if ((float)Math.abs(b) < SMALL_NUM) {
return null;
}
r = a / b;
if (r < 0.0) {
return null;
}
I = new Point3f(R.origin);
I.x += r * dir.x;
I.y += r * dir.y;
I.z += r * dir.z;
return I;
}
Thanks in advance!
I was looking Cropper and image crooper open source App by Edmodo, it does a pretty good job except instead of Image cropping I want to use it to scale my images, my Logic Was everytime the cropper Window/View changes in size I would change the height and width of my imageview to match the Crop view but everytime I do this, nothing happens, but looking at LogCat it seems my height and width do change except the imageview still looks the same even after changes below is the Class, my changes are commented in the onSizeChanged()
/*
* Copyright 2013, Edmodo, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this work except in compliance with the License.
* You may obtain a copy of the License in the LICENSE file, or at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS"
* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language
* governing permissions and limitations under the License.
*/
package com.theartofdev.edmodo.cropper.cropwindow;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Region;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.Pair;
import android.util.TypedValue;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Toast;
import com.theartofdev.edmodo.cropper.CropImageView;
import com.theartofdev.edmodo.cropper.cropwindow.edge.Edge;
import com.theartofdev.edmodo.cropper.cropwindow.handle.Handle;
import com.theartofdev.edmodo.cropper.util.AspectRatioUtil;
import com.theartofdev.edmodo.cropper.util.HandleUtil;
import com.theartofdev.edmodo.cropper.util.PaintUtil;
/**
* A custom View representing the crop window and the shaded background outside the crop window.
*/
public class CropOverlayView extends View {
//region: Fields and Consts
private static final int SNAP_RADIUS_DP = 6;
private static final float DEFAULT_SHOW_GUIDELINES_LIMIT = 100;
// Gets default values from PaintUtil, sets a bunch of values such that the
// corners will draw correctly
private static final float DEFAULT_CORNER_THICKNESS_DP = PaintUtil.getCornerThickness();
private static final float DEFAULT_LINE_THICKNESS_DP = PaintUtil.getLineThickness();
private static final float DEFAULT_CORNER_OFFSET_DP = (DEFAULT_CORNER_THICKNESS_DP / 2) - (DEFAULT_LINE_THICKNESS_DP / 2);
private static final float DEFAULT_CORNER_EXTENSION_DP = DEFAULT_CORNER_THICKNESS_DP / 2
+ DEFAULT_CORNER_OFFSET_DP;
private static final float DEFAULT_CORNER_LENGTH_DP = 20;
private static final int GUIDELINES_ON_TOUCH = 1;
private static final int GUIDELINES_ON = 2;
private static RectF mRectF = new RectF();
/**
* The Paint used to draw the white rectangle around the crop area.
*/
private Paint mBorderPaint;
/**
* The Paint used to draw the guidelines within the crop area when pressed.
*/
private Paint mGuidelinePaint;
/**
* The Paint used to draw the corners of the Border
*/
private Paint mCornerPaint;
/**
* The Paint used to darken the surrounding areas outside the crop area.
*/
private Paint mBackgroundPaint;
/**
* The bounding box around the Bitmap that we are cropping.
*/
private Rect mBitmapRect;
// The radius of the touch zone (in pixels) around a given Handle.
private float mHandleRadius;
// An edge of the crop window will snap to the corresponding edge of a
// specified bounding box when the crop window edge is less than or equal to
// this distance (in pixels) away from the bounding box edge.
private float mSnapRadius;
// Holds the x and y offset between the exact touch location and the exact
// handle location that is activated. There may be an offset because we
// allow for some leeway (specified by mHandleRadius) in activating a
// handle. However, we want to maintain these offset values while the handle
// is being dragged so that the handle doesn't jump.
private Pair<Float, Float> mTouchOffset;
// The Handle that is currently pressed; null if no Handle is pressed.
private Handle mPressedHandle;
// Flag indicating if the crop area should always be a certain aspect ratio
// (indicated by mTargetAspectRatio).
private boolean mFixAspectRatio = CropImageView.DEFAULT_FIXED_ASPECT_RATIO;
// Floats to save the current aspect ratio of the image
private int mAspectRatioX = CropImageView.DEFAULT_ASPECT_RATIO_X;
private int mAspectRatioY = CropImageView.DEFAULT_ASPECT_RATIO_Y;
// The aspect ratio that the crop area should maintain; this variable is
// only used when mMaintainAspectRatio is true.
private float mTargetAspectRatio = ((float) mAspectRatioX) / mAspectRatioY;
/**
* Instance variables for customizable attributes
*/
private int mGuidelines;
/**
* The shape of the cropping area - rectangle/circular.
*/
private CropImageView.CropShape mCropShape;
// Whether the Crop View has been initialized for the first time
private boolean initializedCropWindow = false;
// Instance variables for the corner values
private float mCornerExtension;
private float mCornerOffset;
private float mCornerLength;
//endregion
public CropOverlayView(Context context) {
super(context);
init(context);
}
public CropOverlayView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
/**
* Informs the CropOverlayView of the image's position relative to the
* ImageView. This is necessary to call in order to draw the crop window.
*
* #param bitmapRect the image's bounding box
*/
public void setBitmapRect(Rect bitmapRect) {
mBitmapRect = bitmapRect;
initCropWindow(mBitmapRect);
}
/**
* Resets the crop overlay view.
*/
public void resetCropOverlayView() {
if (initializedCropWindow) {
initCropWindow(mBitmapRect);
invalidate();
}
}
/**
* The shape of the cropping area - rectangle/circular.
*/
public void setCropShape(CropImageView.CropShape cropShape) {
mCropShape = cropShape;
invalidate();
}
/**
* Sets the guidelines for the CropOverlayView to be either on, off, or to
* show when resizing the application.
*
* #param guidelines Integer that signals whether the guidelines should be
* on, off, or only showing when resizing.
*/
public void setGuidelines(int guidelines) {
if (guidelines < 0 || guidelines > 2)
throw new IllegalArgumentException("Guideline value must be set between 0 and 2. See documentation.");
else {
mGuidelines = guidelines;
if (initializedCropWindow) {
initCropWindow(mBitmapRect);
invalidate();
}
}
}
/**
* Sets whether the aspect ratio is fixed or not; true fixes the aspect
* ratio, while false allows it to be changed.
*
* #param fixAspectRatio Boolean that signals whether the aspect ratio
* should be maintained.
*/
public void setFixedAspectRatio(boolean fixAspectRatio) {
mFixAspectRatio = fixAspectRatio;
if (initializedCropWindow) {
initCropWindow(mBitmapRect);
invalidate();
}
}
/**
* Sets the X value of the aspect ratio; is defaulted to 1.
*
* #param aspectRatioX int that specifies the new X value of the aspect
* ratio
*/
public void setAspectRatioX(int aspectRatioX) {
if (aspectRatioX <= 0)
throw new IllegalArgumentException("Cannot set aspect ratio value to a number less than or equal to 0.");
else {
mAspectRatioX = aspectRatioX;
mTargetAspectRatio = ((float) mAspectRatioX) / mAspectRatioY;
if (initializedCropWindow) {
initCropWindow(mBitmapRect);
invalidate();
}
}
}
/**
* Sets the Y value of the aspect ratio; is defaulted to 1.
*
* #param aspectRatioY int that specifies the new Y value of the aspect
* ratio
*/
public void setAspectRatioY(int aspectRatioY) {
if (aspectRatioY <= 0)
throw new IllegalArgumentException("Cannot set aspect ratio value to a number less than or equal to 0.");
else {
mAspectRatioY = aspectRatioY;
mTargetAspectRatio = ((float) mAspectRatioX) / mAspectRatioY;
if (initializedCropWindow) {
initCropWindow(mBitmapRect);
invalidate();
}
}
}
/**
* Sets all initial values, but does not call initCropWindow to reset the
* views. Used once at the very start to initialize the attributes.
*
* #param guidelines Integer that signals whether the guidelines should be
* on, off, or only showing when resizing.
* #param fixAspectRatio Boolean that signals whether the aspect ratio
* should be maintained.
* #param aspectRatioX float that specifies the new X value of the aspect
* ratio
* #param aspectRatioY float that specifies the new Y value of the aspect
* ratio
*/
public void setInitialAttributeValues(int guidelines, boolean fixAspectRatio, int aspectRatioX, int aspectRatioY) {
if (guidelines < 0 || guidelines > 2)
throw new IllegalArgumentException("Guideline value must be set between 0 and 2. See documentation.");
else
mGuidelines = guidelines;
mFixAspectRatio = fixAspectRatio;
if (aspectRatioX <= 0)
throw new IllegalArgumentException("Cannot set aspect ratio value to a number less than or equal to 0.");
else {
mAspectRatioX = aspectRatioX;
mTargetAspectRatio = ((float) mAspectRatioX) / mAspectRatioY;
}
if (aspectRatioY <= 0)
throw new IllegalArgumentException("Cannot set aspect ratio value to a number less than or equal to 0.");
else {
mAspectRatioY = aspectRatioY;
mTargetAspectRatio = ((float) mAspectRatioX) / mAspectRatioY;
}
}
//region: Private methods
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
// Initialize the crop window here because we need the size of the view
// to have been determined.
//my changes to update imageview height and width
CropImageView.mImageView.getLayoutParams().height = h;
CropImageView.mImageView.getLayoutParams().width = w;
CropImageView.mImageView.requestLayout();
CropImageView.mImageView.invalidate();
initCropWindow(mBitmapRect);
// CropImageView.mImageView.invalidate();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// Draw translucent background for the cropped area.
drawBackground(canvas, mBitmapRect);
if (showGuidelines()) {
// Determines whether guidelines should be drawn or not
if (mGuidelines == GUIDELINES_ON) {
drawRuleOfThirdsGuidelines(canvas);
} else if (mGuidelines == GUIDELINES_ON_TOUCH) {
// Draw only when resizing
if (mPressedHandle != null)
drawRuleOfThirdsGuidelines(canvas);
}
}
float w = mBorderPaint.getStrokeWidth();
float l = Edge.LEFT.getCoordinate() + w;
float t = Edge.TOP.getCoordinate() + w;
float r = Edge.RIGHT.getCoordinate() - w;
float b = Edge.BOTTOM.getCoordinate() - w;
if (mCropShape == CropImageView.CropShape.RECTANGLE) {
// Draw rectangle crop window border.
canvas.drawRect(l, t, r, b, mBorderPaint);
drawCorners(canvas);
} else {
// Draw circular crop window border
mRectF.set(l, t, r, b);
canvas.drawOval(mRectF, mBorderPaint);
}
}
#Override
public boolean onTouchEvent(#SuppressWarnings("NullableProblems") MotionEvent event) {
// If this View is not enabled, don't allow for touch interactions.
if (!isEnabled()) {
return false;
}
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
onActionDown(event.getX(), event.getY());
return true;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
getParent().requestDisallowInterceptTouchEvent(false);
onActionUp();
return true;
case MotionEvent.ACTION_MOVE:
onActionMove(event.getX(), event.getY());
getParent().requestDisallowInterceptTouchEvent(true);
return true;
default:
return false;
}
}
private void init(Context context) {
DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
mHandleRadius = HandleUtil.getTargetRadius(context);
mSnapRadius = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
SNAP_RADIUS_DP,
displayMetrics);
mBorderPaint = PaintUtil.newBorderPaint(context);
mGuidelinePaint = PaintUtil.newGuidelinePaint();
mBackgroundPaint = PaintUtil.newBackgroundPaint(context);
mCornerPaint = PaintUtil.newCornerPaint(context);
// Sets the values for the corner sizes
mCornerOffset = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
DEFAULT_CORNER_OFFSET_DP,
displayMetrics);
mCornerExtension = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
DEFAULT_CORNER_EXTENSION_DP,
displayMetrics);
mCornerLength = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
DEFAULT_CORNER_LENGTH_DP,
displayMetrics);
// Sets guidelines to default until specified otherwise
mGuidelines = CropImageView.DEFAULT_GUIDELINES;
}
/**
* Set the initial crop window size and position. This is dependent on the
* size and position of the image being cropped.
*
* #param bitmapRect the bounding box around the image being cropped
*/
private void initCropWindow(Rect bitmapRect) {
if (bitmapRect.width() == 0 || bitmapRect.height() == 0) {
return;
}
// Tells the attribute functions the crop window has already been
// initialized
if (!initializedCropWindow) {
initializedCropWindow = true;
}
if (mFixAspectRatio
&& (bitmapRect.left != 0 || bitmapRect.right != 0
|| bitmapRect.top != 0 || bitmapRect.bottom != 0)) {
// If the image aspect ratio is wider than the crop aspect ratio,
// then the image height is the determining initial length. Else,
// vice-versa.
if (AspectRatioUtil.calculateAspectRatio(bitmapRect) > mTargetAspectRatio) {
Edge.TOP.setCoordinate(bitmapRect.top);
Edge.BOTTOM.setCoordinate(bitmapRect.bottom);
final float centerX = getWidth() / 2f;
//dirty fix for wrong crop overlay aspect ratio when using fixed aspect ratio
mTargetAspectRatio = (float) mAspectRatioX / mAspectRatioY;
// Limits the aspect ratio to no less than 40 wide or 40 tall
final float cropWidth = Math.max(Edge.MIN_CROP_LENGTH_PX,
AspectRatioUtil.calculateWidth(Edge.TOP.getCoordinate(),
Edge.BOTTOM.getCoordinate(),
mTargetAspectRatio));
// Create new TargetAspectRatio if the original one does not fit
// the screen
if (cropWidth == Edge.MIN_CROP_LENGTH_PX) {
mTargetAspectRatio = (Edge.MIN_CROP_LENGTH_PX) / (Edge.BOTTOM.getCoordinate() - Edge.TOP.getCoordinate());
}
final float halfCropWidth = cropWidth / 2f;
Edge.LEFT.setCoordinate(centerX - halfCropWidth);
Edge.RIGHT.setCoordinate(centerX + halfCropWidth);
} else {
Edge.LEFT.setCoordinate(bitmapRect.left);
Edge.RIGHT.setCoordinate(bitmapRect.right);
final float centerY = getHeight() / 2f;
// Limits the aspect ratio to no less than 40 wide or 40 tall
final float cropHeight = Math.max(Edge.MIN_CROP_LENGTH_PX,
AspectRatioUtil.calculateHeight(Edge.LEFT.getCoordinate(),
Edge.RIGHT.getCoordinate(),
mTargetAspectRatio));
// Create new TargetAspectRatio if the original one does not fit
// the screen
if (cropHeight == Edge.MIN_CROP_LENGTH_PX) {
mTargetAspectRatio = (Edge.RIGHT.getCoordinate() - Edge.LEFT.getCoordinate()) / Edge.MIN_CROP_LENGTH_PX;
}
final float halfCropHeight = cropHeight / 2f;
Edge.TOP.setCoordinate(centerY - halfCropHeight);
Edge.BOTTOM.setCoordinate(centerY + halfCropHeight);
}
} else { // ... do not fix aspect ratio...
// Initialize crop window to have 10% padding w/ respect to image.
final float horizontalPadding = 0.1f * bitmapRect.width();
final float verticalPadding = 0.1f * bitmapRect.height();
Edge.LEFT.setCoordinate(bitmapRect.left + horizontalPadding);
Edge.TOP.setCoordinate(bitmapRect.top + verticalPadding);
Edge.RIGHT.setCoordinate(bitmapRect.right - horizontalPadding);
Edge.BOTTOM.setCoordinate(bitmapRect.bottom - verticalPadding);
}
}
/**
* Indicates whether the crop window is small enough that the guidelines
* should be shown. Public because this function is also used to determine
* if the center handle should be focused.
*
* #return boolean Whether the guidelines should be shown or not
*/
public static boolean showGuidelines() {
if ((Math.abs(Edge.LEFT.getCoordinate() - Edge.RIGHT.getCoordinate()) < DEFAULT_SHOW_GUIDELINES_LIMIT)
|| (Math.abs(Edge.TOP.getCoordinate() - Edge.BOTTOM.getCoordinate()) < DEFAULT_SHOW_GUIDELINES_LIMIT)) {
return false;
} else {
return true;
}
}
private void drawRuleOfThirdsGuidelines(Canvas canvas) {
float w = mBorderPaint.getStrokeWidth();
float l = Edge.LEFT.getCoordinate() + w;
float t = Edge.TOP.getCoordinate() + w;
float r = Edge.RIGHT.getCoordinate() - w;
float b = Edge.BOTTOM.getCoordinate() - w;
if (mCropShape == CropImageView.CropShape.OVAL) {
l += 15 * mGuidelinePaint.getStrokeWidth();
t += 15 * mGuidelinePaint.getStrokeWidth();
r -= 15 * mGuidelinePaint.getStrokeWidth();
b -= 15 * mGuidelinePaint.getStrokeWidth();
}
// Draw vertical guidelines.
final float oneThirdCropWidth = Edge.getWidth() / 3;
final float x1 = l + oneThirdCropWidth;
canvas.drawLine(x1, t, x1, b, mGuidelinePaint);
final float x2 = r - oneThirdCropWidth;
canvas.drawLine(x2, t, x2, b, mGuidelinePaint);
// Draw horizontal guidelines.
final float oneThirdCropHeight = Edge.getHeight() / 3;
final float y1 = t + oneThirdCropHeight;
canvas.drawLine(l, y1, r, y1, mGuidelinePaint);
final float y2 = b - oneThirdCropHeight;
canvas.drawLine(l, y2, r, y2, mGuidelinePaint);
}
private void drawBackground(Canvas canvas, Rect bitmapRect) {
final float l = Edge.LEFT.getCoordinate();
final float t = Edge.TOP.getCoordinate();
final float r = Edge.RIGHT.getCoordinate();
final float b = Edge.BOTTOM.getCoordinate();
if (mCropShape == CropImageView.CropShape.RECTANGLE) {
canvas.drawRect(bitmapRect.left, bitmapRect.top, bitmapRect.right, t, mBackgroundPaint);
canvas.drawRect(bitmapRect.left, b, bitmapRect.right, bitmapRect.bottom, mBackgroundPaint);
canvas.drawRect(bitmapRect.left, t, l, b, mBackgroundPaint);
canvas.drawRect(r, t, bitmapRect.right, b, mBackgroundPaint);
} else {
Path circleSelectionPath = new Path();
mRectF.set(l, t, r, b);
circleSelectionPath.addOval(mRectF, Path.Direction.CW);
canvas.clipPath(circleSelectionPath, Region.Op.XOR);
canvas.drawRect(bitmapRect.left, bitmapRect.top, bitmapRect.right, bitmapRect.bottom, mBackgroundPaint);
canvas.restore();
}
}
private void drawCorners(Canvas canvas) {
float w = mBorderPaint.getStrokeWidth();
final float l = Edge.LEFT.getCoordinate() + w;
final float t = Edge.TOP.getCoordinate() + w;
final float r = Edge.RIGHT.getCoordinate() - w;
final float b = Edge.BOTTOM.getCoordinate() - w;
// Top left
canvas.drawLine(l - mCornerOffset, t - mCornerExtension, l - mCornerOffset, t + mCornerLength, mCornerPaint);
canvas.drawLine(l, t - mCornerOffset, l + mCornerLength, t - mCornerOffset, mCornerPaint);
// Top right
canvas.drawLine(r + mCornerOffset, t - mCornerExtension, r + mCornerOffset, t + mCornerLength, mCornerPaint);
canvas.drawLine(r, t - mCornerOffset, r - mCornerLength, t - mCornerOffset, mCornerPaint);
// Bottom left
canvas.drawLine(l - mCornerOffset, b + mCornerExtension, l - mCornerOffset, b - mCornerLength, mCornerPaint);
canvas.drawLine(l, b + mCornerOffset, l + mCornerLength, b + mCornerOffset, mCornerPaint);
// Bottom left
canvas.drawLine(r + mCornerOffset, b + mCornerExtension, r + mCornerOffset, b - mCornerLength, mCornerPaint);
canvas.drawLine(r, b + mCornerOffset, r - mCornerLength, b + mCornerOffset, mCornerPaint);
}
/**
* Handles a {#link android.view.MotionEvent#ACTION_DOWN} event.
*
* #param x the x-coordinate of the down action
* #param y the y-coordinate of the down action
*/
private void onActionDown(float x, float y) {
final float left = Edge.LEFT.getCoordinate();
final float top = Edge.TOP.getCoordinate();
final float right = Edge.RIGHT.getCoordinate();
final float bottom = Edge.BOTTOM.getCoordinate();
mPressedHandle = HandleUtil.getPressedHandle(x, y, left, top, right, bottom, mHandleRadius);
if (mPressedHandle == null) {
return;
}
// Calculate the offset of the touch point from the precise location
// of the handle. Save these values in a member variable since we want
// to maintain this offset as we drag the handle.
mTouchOffset = HandleUtil.getOffset(mPressedHandle, x, y, left, top, right, bottom);
invalidate();
}
/**
* Handles a {#link android.view.MotionEvent#ACTION_UP} or
* {#link android.view.MotionEvent#ACTION_CANCEL} event.
*/
private void onActionUp() {
if (mPressedHandle == null) {
return;
}
mPressedHandle = null;
invalidate();
}
/**
* Handles a {#link android.view.MotionEvent#ACTION_MOVE} event.
*
* #param x the x-coordinate of the move event
* #param y the y-coordinate of the move event
*/
private void onActionMove(float x, float y) {
if (mPressedHandle == null) {
return;
}
// Adjust the coordinates for the finger position's offset (i.e. the
// distance from the initial touch to the precise handle location).
// We want to maintain the initial touch's distance to the pressed
// handle so that the crop window size does not "jump".
x += mTouchOffset.first;
y += mTouchOffset.second;
// Calculate the new crop window size/position.
if (mFixAspectRatio) {
mPressedHandle.updateCropWindow(x, y, mTargetAspectRatio, mBitmapRect, mSnapRadius);
} else {
mPressedHandle.updateCropWindow(x, y, mBitmapRect, mSnapRadius);
}
invalidate();
}
//endregion
}
You could just try using Picasso. It does all the scaling for you in the background after you put it into your Gradle build. Picasso
I have tried implementing a smooth Camera zoom method in libgdx, in which he method zoom interpolates between two vlaues of zoom amount i.e initial * final.
The problem howevever is that the camera snaps fast into position when zoomed or moved. How can I be able to create a smooth camera class and implement zoom without having a jumpy scrren?
private void panZoom(Vector3 spanCord, TweenManager tweenManager, GameWorld world)
{
/*
* Example Tween-Sequence: Zoom to 120%, Pan to point of interest #1 (0, -50), Wait 1 second, Pan back to the
* starting position, Zoom back to the initial value
*/
Timeline.createSequence()
.beginParallel()
.push(Tween.to(this, OrthographicCameraAccessor.POSITION, 3.5f).target(spanCord.x,spanCord.y,spanCord.z).ease(Elastic.OUT))
.push(Tween.to(this, OrthographicCameraAccessor.ZOOM, 3.5f).target(1.20f).ease(Elastic.OUT))
.end()
.beginParallel()
.push(Tween.to(this, OrthographicCameraAccessor.POSITION, 2.8f).target(world.getYoyo().position.x,0,0).ease(Bounce.INOUT))
.push(Tween.to(this, OrthographicCameraAccessor.ZOOM, 3.0f).target(1).ease(Bounce.INOUT))
.end()
.start(tweenManager);
}
public float calcZoom(float initialDistance, float distance)
{
float nextZoom;
if(initialDistance < distance)
{
float ratio = (initialDistance/distance)/10;
nextZoom = zoomIn(ratio);
}
else
{
float ratio = (distance/initialDistance)/10;
nextZoom = zoomOut(ratio);
}
return nextZoom;
}
public class OrthographicCameraAccessor implements TweenAccessor<MyOrthographicCamera> {
/** Tween position */
public static final int POSITION = 1;
/** Tween zoom */
public static final int ZOOM = 2;
/**
* #param camera
* camera to get values from
* #param tweentype
* type of tween (Position or Zoom)
* #param returnValues
* out parameter with the requested values
*/
#Override
public int getValues(MyOrthographicCamera camera, int tweenType, float[] returnValues)
{
switch (tweenType)
{
case POSITION:
returnValues[0] = camera.position.x;
returnValues[1] = camera.position.y;
returnValues[2] = camera.position.z;
return 3;
case ZOOM:
returnValues[0] = camera.zoom;
return 1;
default:
return 0;
}
}
/**
* #param camera
* camera whose some values are going to be set
* #param tweenType
* Position or Zoom
* #param newValues
* array containing the new values to configure the camera
*/
#Override
public void setValues(MyOrthographicCamera camera, int tweenType, float[] newValues)
{
switch (tweenType)
{
case POSITION:
camera.setPosition(newValues[0], 0);
camera.update();
break;
case ZOOM:
camera.setZoom(newValues[0]);
camera.update();
Gdx.app.log("CAMERA", "Clamped Zoom" +camera.zoom);
break;
default:
break;
}
}
Solved, used this code:
if ( !isClockwise(TempVectArray) ) { Collections.reverse(TempVectArray); }
...
private boolean isClockwise(ArrayList<Vec2> arl){
Iterator<Vec2> it = arl.iterator();
Vec2 pt1 = (Vec2)it.next();
Vec2 firstPt = pt1;
Vec2 lastPt = null;
double area = 0.0;
while(it.hasNext()){
Vec2 pt2 = (Vec2) it.next();
area += (((pt2.x - pt1.x) * (pt2.y + pt1.y)) / 2);
pt1 = pt2;
lastPt = pt1;
}
area += (((firstPt.x - lastPt.x) * (firstPt.y + lastPt.y)) / 2);
return area < 0;
}
Suppose I get a vertex array from the user tapping on the screen, but need it to be clockwise.
Maybe you know of some standard methods to check if it is clockwise and if it's not, then make it clockwise?
Thanks!
One way to do it is to first calculate the average point, and then sort everything around it by angle. Should be something like this:
public static void sortPointsClockwise(ArrayList<PointF> points) {
float averageX = 0;
float averageY = 0;
for (PointF point : points) {
averageX += point.x;
averageY += point.y;
}
final float finalAverageX = averageX / points.size();
final float finalAverageY = averageY / points.size();
Comparator<PointF> comparator = new Comparator<PointF>() {
public int compare(PointF lhs, PointF rhs) {
double lhsAngle = Math.atan2(lhs.y - finalAverageY, lhs.x - finalAverageX);
double rhsAngle = Math.atan2(rhs.y - finalAverageY, rhs.x - finalAverageX);
// Depending on the coordinate system, you might need to reverse these two conditions
if (lhsAngle < rhsAngle) return -1;
if (lhsAngle > rhsAngle) return 1;
return 0;
}
};
Collections.sort(points, comparator);
}
public static void sortPointsCounterClockwise(ArrayList<PointF> points) {
sortPointsClockwise(points);
Collections.reverse(points);
}
You have the sequence numbers and positions of the nodes. Get the movements which hold x and y changes in the move. All left to do is define a control structure such as:
if(movement_before is "up")
movement should-be "up" or "up-right"
if(movement_before is "up-left")
movement should-be "up" or "up-left" or "up-right"
etc..
i am looking for an animation for a view flipper.
How would i go about animating so that the view basically goes back to front when a button is pressed. where there is a map view on one side and a listview on the other.
i have the above working except for the animation . could someone help or explain android animations to me
edit added here
here is some code for animation for rotation, how could i implment this in xml
public class Rotate3dAnimation extends Animation {
private final float mFromDegrees;
private final float mToDegrees;
private final float mCenterX;
private final float mCenterY;
private final float mDepthZ;
private final boolean mReverse;
private Camera mCamera;
/**
* Creates a new 3D rotation on the Y axis. The rotation is defined by its
* start angle and its end angle. Both angles are in degrees. The rotation
* is performed around a center point on the 2D space, definied by a pair
* of X and Y coordinates, called centerX and centerY. When the animation
* starts, a translation on the Z axis (depth) is performed. The length
* of the translation can be specified, as well as whether the translation
* should be reversed in time.
*
* #param fromDegrees the start angle of the 3D rotation
* #param toDegrees the end angle of the 3D rotation
* #param centerX the X center of the 3D rotation
* #param centerY the Y center of the 3D rotation
* #param reverse true if the translation should be reversed, false otherwise
*/
public Rotate3dAnimation(float fromDegrees, float toDegrees,
float centerX, float centerY, float depthZ, boolean reverse) {
mFromDegrees = fromDegrees;
mToDegrees = toDegrees;
mCenterX = centerX;
mCenterY = centerY;
mDepthZ = depthZ;
mReverse = reverse;
}
#Override
public void initialize(int width, int height, int parentWidth, int parentHeight) {
super.initialize(width, height, parentWidth, parentHeight);
mCamera = new Camera();
}
#Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
final float fromDegrees = mFromDegrees;
float degrees = fromDegrees + ((mToDegrees - fromDegrees) * interpolatedTime);
final float centerX = mCenterX;
final float centerY = mCenterY;
final Camera camera = mCamera;
final Matrix matrix = t.getMatrix();
camera.save();
if (mReverse) {
camera.translate(0.0f, 0.0f, mDepthZ * interpolatedTime);
} else {
camera.translate(0.0f, 0.0f, mDepthZ * (1.0f - interpolatedTime));
}
camera.rotateY(degrees);
camera.getMatrix(matrix);
camera.restore();
matrix.preTranslate(-centerX, -centerY);
matrix.postTranslate(centerX, centerY);
}
}
It depends on what you want to do but you can lookup wiEngine for Android SDK, at the transitions example... take a look at the code thought the documentation is in chinese, you can simply read the code.
Also take a look at Chet Haase blog for some tips, http://graphics-geek.blogspot.com/ he has a bunch of stuff related to animation. Targeting API level12 that would take just about one line of code using the method objectToAnimate.rotateYBy(360).setDuration(250f)