Develop Reference

How to infinitely repeat background in Libgdx?

I am using this class :
import com.badlogic.gdx.graphics.g2d.TextureRegion;
public class ParallaxLayer {
// the Texture sitting on this layer
public TextureRegion region;
/**
* how much shall this layer (in percent) be moved if the whole background is moved
* 0.5f is half as fast as the speed
* 2.0f is twice the speed
*/
float ratioX, ratioY;
/**
* current position
*/
float positionX, positionY;
/**
*
* #param pRegion
* #param pRatioX
* #param pRatioY
*/
public ParallaxLayer(TextureRegion pRegion, float pRatioX, float pRatioY) {
region = pRegion;
ratioX = pRatioX;
ratioY = pRatioY;
}
/**
* move this layer
* #param pDelta
*/
protected void moveX(float pDelta) {
positionX += pDelta * ratioX;
}
/**
* move this layer
* #param pDelta
*/
protected void moveY(float pDelta) {
positionY += pDelta * ratioY;
}
}
and this class :
import com.badlogic.gdx.graphics.g2d.TextureRegion;
public class ParallaxLayer {
/**
* the Texture sitting on this layer
*/
public TextureRegion region;
/**
* how much shall this layer (in percent) be moved if the whole background is moved
* 0.5f is half as fast as the speed
* 2.0f is twice the speed
*/
float ratioX, ratioY;
/**
* current position
*/
float positionX, positionY;
/**
*
* #param pRegion
* #param pRatioX
* #param pRatioY
*/
public ParallaxLayer(TextureRegion pRegion, float pRatioX, float pRatioY) {
region = pRegion;
ratioX = pRatioX;
ratioY = pRatioY;
}
/**
* move this layer
* #param pDelta
*/
protected void moveX(float pDelta) {
positionX += pDelta * ratioX;
}
/**
* move this layer
* #param pDelta
*/
protected void moveY(float pDelta) {
positionY += pDelta * ratioY;
}
}
And in main class :
camera=new OrthographicCamera(400,240);
camera.position.x=200;
camera.position.y=120;
camera.update();
batch=new SpriteBatch();
layer1=atlas.findRegion("layer1");
layer2=atlas.findRegion("layer2");
layer3=atlas.findRegion("layer3");
ParallaxLayer l1=new ParallaxLayer(layer1,0,0);
ParallaxLayer l2=new ParallaxLayer(layer2,0.5f,0);
ParallaxLayer l3=new ParallaxLayer(layer3,1,0);
ParallaxLayer[] layers={l1,l2,l3};
background=new ParallaxBackground(layers, camera,batch);
// [...] in render
background.moveX(30*delta); // move to the right to show the effect
background.render();
to achieve parallax scrolling effect but i want infinite scrolling but unable to get it. I tried doing this in ParallaxBackground class under for loop but repeats only three time.
posXbg1L1 = layer.positionX;
posXbg2L1 = posXbg1L1 - layer.region.getRegionWidth();
if (camera.position.x <= posXbg2L1 - camera.viewportWidth / 2) {
// Gdx.app.log("TAG", camera.position.x + ":" + posXbg2L1 + camera.viewportWidth / 2);
posXbg1L1 = posXbg2L1;
}
batch.draw(layer.region, -camera.viewportWidth / 2
- posXbg1L1, -camera.viewportHeight / 2
- layer.positionY);
batch.draw(layer.region, -camera.viewportWidth / 2
- posXbg2L1, -camera.viewportHeight / 2
- layer.positionY);
}
Any psuedocode/code will be helpful.

You could try something like this:
TextureRegion[] backgrounds = [...your array of background textures...];
float[] parallax = {...your parallax coefficients...}; //For example {0.2f, 0.1f}
public void drawLayers(Batch batch, OrthographicCamera camera) {
batch.setColor(Color.WHITE);
for(int b = backgrounds.length - 1; b >= 0; b--) {
TextureRegion background = backgrounds[b];
if(background != null) {
float x = (camera.position.x - camera.viewportWidth / 2f * camera.zoom);
float y = camera.position.y - camera.viewportHeight / 2f * camera.zoom + camera.viewportHeight / 15f * camera.zoom;
float rWidth = camera.viewportWidth * 1.5f * camera.zoom;
float rHeight = (rWidth / background.getRegionWidth()) * background.getRegionHeight();
drawParallaxLayer(batch, background, parallax[b], x, y, rWidth, rHeight);
}
}
}
public static void drawParallaxLayer(Batch batch, TextureRegion region, float parallax, float x, float y, float width, float height) {
for(int j = 0; j < 3; j++) {
batch.draw(region, x + (j * width) - ((x * parallax) % width) - (width / 2f), y, width, height);
}
}
You might have to adjust some of the position/width/height values in the drawLayers function, but the real magic happens in drawParallaxLayer - which should be able to stay the same.

textView getting null exception in customView

this is page-curl view , i want when nextView() is called my TextView get the next string
but I can't use TextView from xml layout it gives me null ,
how I can but buttons and TextView in customView ?
can any one help me to solve this with code ?
I have searched with many tutorials but I get this understanding
activity class :
public class StandaloneExample extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(R.layout.standalone_example);
}
#Override
public void onDestroy(){
super.onDestroy();
System.gc();
finish();
}
/**
* Set the current orientation to landscape. This will prevent the OS from changing
* the app's orientation.
*/
public void lockOrientationLandscape() {
lockOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
}
/**
* Set the current orientation to portrait. This will prevent the OS from changing
* the app's orientation.
*/
public void lockOrientationPortrait() {
lockOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
}
public void lockOrientation( int orientation ) {
setRequestedOrientation(orientation);
}
}
pageCurlView :
public class PageCurlView extends View {
private class Vector2D {
public float x, y;
public Vector2D(float x, float y) {
this.x = x;
this.y = y;
}
#Override
public String toString() {
// TODO Auto-generated method stub
return "(" + this.x + "," + this.y + ")";
}
public float length() {
return (float) Math.sqrt(x * x + y * y);
}
public float lengthSquared() {
return (x * x) + (y * y);
}
public boolean equals(Object o) {
if (o instanceof Vector2D) {
Vector2D p = (Vector2D) o;
return p.x == x && p.y == y;
}
return false;
}
public Vector2D reverse() {
return new Vector2D(-x, -y);
}
public Vector2D sum(Vector2D b) {
return new Vector2D(x + b.x, y + b.y);
}
public Vector2D sub(Vector2D b) {
return new Vector2D(x - b.x, y - b.y);
}
public float dot(Vector2D vec) {
return (x * vec.x) + (y * vec.y);
}
public float cross(Vector2D a, Vector2D b) {
return a.cross(b);
}
public float cross(Vector2D vec) {
return x * vec.y - y * vec.x;
}
public float distanceSquared(Vector2D other) {
float dx = other.x - x;
float dy = other.y - y;
return (dx * dx) + (dy * dy);
}
public float distance(Vector2D other) {
return (float) Math.sqrt(distanceSquared(other));
}
public float dotProduct(Vector2D other) {
return other.x * x + other.y * y;
}
public Vector2D normalize() {
float magnitude = (float) Math.sqrt(dotProduct(this));
return new Vector2D(x / magnitude, y / magnitude);
}
public Vector2D mult(float scalar) {
return new Vector2D(x * scalar, y * scalar);
}
}
/**
* Inner class used to make a fixed timed animation of the curl effect.
*/
class FlipAnimationHandler extends Handler {
#Override
public void handleMessage(Message msg) {
PageCurlView.this.FlipAnimationStep();
}
public void sleep(long millis) {
this.removeMessages(0);
sendMessageDelayed(obtainMessage(0), millis);
}
}
/**
* Base
*
* #param context
*/
public PageCurlView(Context context) {
super(context);
init(context);
ResetClipEdge();
}
/**
* Construct the object from an XML file. Valid Attributes:
*
* #see android.view.View#View(android.content.Context,
* android.util.AttributeSet)
*/
public PageCurlView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
// Get the data from the XML AttributeSet
{
TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.PageCurlView);
// Get data
bEnableDebugMode = a.getBoolean(
R.styleable.PageCurlView_enableDebugMode, bEnableDebugMode);
mCurlSpeed = a.getInt(R.styleable.PageCurlView_curlSpeed,
mCurlSpeed);
mUpdateRate = a.getInt(R.styleable.PageCurlView_updateRate,
mUpdateRate);
mInitialEdgeOffset = a.getInt(
R.styleable.PageCurlView_initialEdgeOffset,
mInitialEdgeOffset);
mCurlMode = a.getInt(R.styleable.PageCurlView_curlMode, mCurlMode);
Log.i(TAG, "mCurlSpeed: " + mCurlSpeed);
Log.i(TAG, "mUpdateRate: " + mUpdateRate);
Log.i(TAG, "mInitialEdgeOffset: " + mInitialEdgeOffset);
Log.i(TAG, "mCurlMode: " + mCurlMode);
// recycle object (so it can be used by others)
a.recycle();
}
ResetClipEdge();
}
/**
* Initialize the view
*/
private final void init(Context context) {
LayoutInflater.from(context).inflate(R.layout.standalone_example, null,
true);
// left text view
textViewContent = (TextView) this.findViewById(R.id.textView);
// Foreground text paint
mTextPaint = new Paint();
mTextPaint.setAntiAlias(true);
mTextPaint.setTextSize(16);
mTextPaint.setColor(0xFF000000);
// The shadow
mTextPaintShadow = new TextPaint();
mTextPaintShadow.setAntiAlias(true);
mTextPaintShadow.setTextSize(16);
mTextPaintShadow.setColor(0x00000000);
// Cache the context
mContext = new WeakReference<Context>(context);
hesham = context;
// Base padding
setPadding(3, 3, 3, 3);
// The focus flags are needed
setFocusable(true);
setFocusableInTouchMode(true);
mMovement = new Vector2D(0, 0);
mFinger = new Vector2D(0, 0);
mOldMovement = new Vector2D(0, 0);
// Create our curl animation handler
mAnimationHandler = new FlipAnimationHandler();
// Create our edge paint
mCurlEdgePaint = new Paint();
mCurlEdgePaint.setColor(Color.WHITE);
mCurlEdgePaint.setAntiAlias(true);
mCurlEdgePaint.setStyle(Paint.Style.FILL);
mCurlEdgePaint.setShadowLayer(10, -5, 5, 0x99000000);
// Set the default props, those come from an XML :D
mCurlSpeed = 120;
mUpdateRate = 66;
mInitialEdgeOffset = 30;
mCurlMode = 2;
// LEGACY PAGE HANDLING!
// Create pages
mPages = new ArrayList<Bitmap>();
mPages.add(BitmapFactory.decodeResource(getResources(),
R.drawable.page1));
mPages.add(BitmapFactory.decodeResource(getResources(),
R.drawable.page2));
// Create some sample images
mForeground = mPages.get(0);
mBackground = mPages.get(1);
}
/**
* Reset points to it's initial clip edge state
*/
public void ResetClipEdge() {
// Set our base movement
mMovement.x = mInitialEdgeOffset;
mMovement.y = mInitialEdgeOffset;
mOldMovement.x = 0;
mOldMovement.y = 0;
// Now set the points
// TODO: OK, those points MUST come from our measures and
// the actual bounds of the view!
mA = new Vector2D(mInitialEdgeOffset, 0);
mB = new Vector2D(this.getWidth(), this.getHeight());
mC = new Vector2D(this.getWidth(), 0);
mD = new Vector2D(0, 0);
mE = new Vector2D(0, 0);
mF = new Vector2D(0, 0);
mOldF = new Vector2D(0, 0);
// The movement origin point
mOrigin = new Vector2D(this.getWidth(), 0);
}
/**
* Return the context which created use. Can return null if the context has
* been erased.
*/
private Context GetContext() {
return mContext.get();
}
/**
* See if the current curl mode is dynamic
*
* #return TRUE if the mode is CURLMODE_DYNAMIC, FALSE otherwise
*/
public boolean IsCurlModeDynamic() {
return mCurlMode == CURLMODE_DYNAMIC;
}
/**
* Set the curl speed.
*
* #param curlSpeed
* - New speed in px/frame
* #throws IllegalArgumentException
* if curlspeed < 1
*/
public void SetCurlSpeed(int curlSpeed) {
if (curlSpeed < 1)
throw new IllegalArgumentException(
"curlSpeed must be greated than 0");
mCurlSpeed = curlSpeed;
}
/**
* Get the current curl speed
*
* #return int - Curl speed in px/frame
*/
public int GetCurlSpeed() {
return mCurlSpeed;
}
/**
* Set the update rate for the curl animation
*
* #param updateRate
* - Fixed animation update rate in fps
* #throws IllegalArgumentException
* if updateRate < 1
*/
public void SetUpdateRate(int updateRate) {
if (updateRate < 1)
throw new IllegalArgumentException(
"updateRate must be greated than 0");
mUpdateRate = updateRate;
}
/**
* Get the current animation update rate
*
* #return int - Fixed animation update rate in fps
*/
public int GetUpdateRate() {
return mUpdateRate;
}
/**
* Set the initial pixel offset for the curl edge
*
* #param initialEdgeOffset
* - px offset for curl edge
* #throws IllegalArgumentException
* if initialEdgeOffset < 0
*/
public void SetInitialEdgeOffset(int initialEdgeOffset) {
if (initialEdgeOffset < 0)
throw new IllegalArgumentException(
"initialEdgeOffset can not negative");
mInitialEdgeOffset = initialEdgeOffset;
}
/**
* Get the initial pixel offset for the curl edge
*
* #return int - px
*/
public int GetInitialEdgeOffset() {
return mInitialEdgeOffset;
}
/**
* Set the curl mode.
* <p>
* Can be one of the following values:
* </p>
* <table>
* <colgroup align="left" /> <colgroup align="left" />
* <tr>
* <th>Value</th>
* <th>Description</th>
* </tr>
* <tr>
* <td>
* <code>{#link #CURLMODE_SIMPLE com.dcg.pagecurl:CURLMODE_SIMPLE}</code></td>
* <td>Curl target will move only in one axis.</td>
* </tr>
* <tr>
* <td>
* <code>{#link #CURLMODE_DYNAMIC com.dcg.pagecurl:CURLMODE_DYNAMIC}</code></td>
* <td>Curl target will move on both X and Y axis.</td>
* </tr>
* </table>
*
* #see #CURLMODE_SIMPLE
* #see #CURLMODE_DYNAMIC
* #param curlMode
* #throws IllegalArgumentException
* if curlMode is invalid
*/
public void SetCurlMode(int curlMode) {
if (curlMode != CURLMODE_SIMPLE && curlMode != CURLMODE_DYNAMIC)
throw new IllegalArgumentException("Invalid curlMode");
mCurlMode = curlMode;
}
/**
* Return an integer that represents the current curl mode.
* <p>
* Can be one of the following values:
* </p>
* <table>
* <colgroup align="left" /> <colgroup align="left" />
* <tr>
* <th>Value</th>
* <th>Description</th>
* </tr>
* <tr>
* <td>
* <code>{#link #CURLMODE_SIMPLE com.dcg.pagecurl:CURLMODE_SIMPLE}</code></td>
* <td>Curl target will move only in one axis.</td>
* </tr>
* <tr>
* <td>
* <code>{#link #CURLMODE_DYNAMIC com.dcg.pagecurl:CURLMODE_DYNAMIC}</code></td>
* <td>Curl target will move on both X and Y axis.</td>
* </tr>
* </table>
*
* #see #CURLMODE_SIMPLE
* #see #CURLMODE_DYNAMIC
* #return int - current curl mode
*/
public int GetCurlMode() {
return mCurlMode;
}
/**
* Enable debug mode. This will draw a lot of data in the view so you can
* track what is happening
*
* #param bFlag
* - boolean flag
*/
public void SetEnableDebugMode(boolean bFlag) {
bEnableDebugMode = bFlag;
}
/**
* Check if we are currently in debug mode.
*
* #return boolean - If TRUE debug mode is on, FALSE otherwise.
*/
public boolean IsDebugModeEnabled() {
return bEnableDebugMode;
}
/**
* #see android.view.View#measure(int, int)
*/
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int finalWidth, finalHeight;
finalWidth = measureWidth(widthMeasureSpec);
finalHeight = measureHeight(heightMeasureSpec);
setMeasuredDimension(finalWidth, finalHeight);
}
/**
* Determines the width of this view
*
* #param measureSpec
* A measureSpec packed into an int
* #return The width of the view, honoring constraints from measureSpec
*/
private int measureWidth(int measureSpec) {
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if (specMode == MeasureSpec.EXACTLY) {
// We were told how big to be
result = specSize;
} else {
// Measure the text
result = specSize;
}
return result;
}
/**
* Determines the height of this view
*
* #param measureSpec
* A measureSpec packed into an int
* #return The height of the view, honoring constraints from measureSpec
*/
private int measureHeight(int measureSpec) {
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if (specMode == MeasureSpec.EXACTLY) {
// We were told how big to be
result = specSize;
} else {
// Measure the text (beware: ascent is a negative number)
result = specSize;
}
return result;
}
/**
* Render the text
*
* #see android.view.View#onDraw(android.graphics.Canvas)
*/
// #Override
// protected void onDraw(Canvas canvas) {
// super.onDraw(canvas);
// canvas.drawText(mText, getPaddingLeft(), getPaddingTop() - mAscent,
// mTextPaint);
// }
// ---------------------------------------------------------------
// Curling. This handles touch events, the actual curling
// implementations and so on.
// ---------------------------------------------------------------
#Override
public boolean onTouchEvent(MotionEvent event) {
if (!bBlockTouchInput) {
// Get our finger position
mFinger.x = event.getX();
mFinger.y = event.getY();
int width = getWidth();
// Depending on the action do what we need to
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mOldMovement.x = mFinger.x;
mOldMovement.y = mFinger.y;
// If we moved over the half of the display flip to next
if (mOldMovement.x > (width >> 1)) {
mMovement.x = mInitialEdgeOffset;
mMovement.y = mInitialEdgeOffset;
// Set the right movement flag
bFlipRight = true;
} else {
// Set the left movement flag
bFlipRight = false;
// go to next previous page
previousView();
// Set new movement
mMovement.x = IsCurlModeDynamic() ? width << 1 : width;
mMovement.y = mInitialEdgeOffset;
}
break;
case MotionEvent.ACTION_UP:
bUserMoves = false;
bFlipping = true;
FlipAnimationStep();
break;
case MotionEvent.ACTION_MOVE:
bUserMoves = true;
// Get movement
mMovement.x -= mFinger.x - mOldMovement.x;
mMovement.y -= mFinger.y - mOldMovement.y;
mMovement = CapMovement(mMovement, true);
// Make sure the y value get's locked at a nice level
if (mMovement.y <= 1)
mMovement.y = 1;
// Get movement direction
if (mFinger.x < mOldMovement.x) {
bFlipRight = true;
} else {
bFlipRight = false;
}
// Save old movement values
mOldMovement.x = mFinger.x;
mOldMovement.y = mFinger.y;
// Force a new draw call
DoPageCurl();
this.invalidate();
break;
}
}
// TODO: Only consume event if we need to.
return true;
}
/**
* Make sure we never move too much, and make sure that if we move too much
* to add a displacement so that the movement will be still in our radius.
*
* #paramradius - radius form the flip origin
* #param bMaintainMoveDir
* - Cap movement but do not change the current movement
* direction
* #return Corrected point
*/
private Vector2D CapMovement(Vector2D point, boolean bMaintainMoveDir) {
// Make sure we never ever move too much
if (point.distance(mOrigin) > mFlipRadius) {
if (bMaintainMoveDir) {
// Maintain the direction
point = mOrigin.sum(point.sub(mOrigin).normalize()
.mult(mFlipRadius));
} else {
// Change direction
if (point.x > (mOrigin.x + mFlipRadius))
point.x = (mOrigin.x + mFlipRadius);
else if (point.x < (mOrigin.x - mFlipRadius))
point.x = (mOrigin.x - mFlipRadius);
point.y = (float) (Math.sin(Math.acos(Math.abs(point.x
- mOrigin.x)
/ mFlipRadius)) * mFlipRadius);
}
}
return point;
}
/**
* Execute a step of the flip animation
*/
public void FlipAnimationStep() {
if (!bFlipping)
return;
int width = getWidth();
// No input when flipping
bBlockTouchInput = true;
// Handle speed
float curlSpeed = mCurlSpeed;
if (!bFlipRight)
curlSpeed *= -1;
// Move us
mMovement.x += curlSpeed;
mMovement = CapMovement(mMovement, false);
// Create values
DoPageCurl();
// Check for endings :D
if (mA.x < 1 || mA.x > width - 1) {
bFlipping = false;
if (bFlipRight) {
// SwapViews();
nextView();
}
ResetClipEdge();
// Create values
DoPageCurl();
// Enable touch input after the next draw event
bEnableInputAfterDraw = true;
} else {
mAnimationHandler.sleep(mUpdateRate);
}
// Force a new draw call
this.invalidate();
}
/**
* Do the page curl depending on the methods we are using
*/
private void DoPageCurl() {
if (bFlipping) {
if (IsCurlModeDynamic())
doDynamicCurl();
else
doSimpleCurl();
} else {
if (IsCurlModeDynamic())
doDynamicCurl();
else
doSimpleCurl();
}
}
/**
* Do a simple page curl effect
*/
private void doSimpleCurl() {
int width = getWidth();
int height = getHeight();
// Calculate point A
mA.x = width - mMovement.x;
mA.y = height;
// Calculate point D
mD.x = 0;
mD.y = 0;
if (mA.x > width / 2) {
mD.x = width;
mD.y = height - (width - mA.x) * height / mA.x;
} else {
mD.x = 2 * mA.x;
mD.y = 0;
}
// Now calculate E and F taking into account that the line
// AD is perpendicular to FB and EC. B and C are fixed points.
double angle = Math
.atan((height - mD.y) / (mD.x + mMovement.x - width));
double _cos = Math.cos(2 * angle);
double _sin = Math.sin(2 * angle);
// And get F
mF.x = (float) (width - mMovement.x + _cos * mMovement.x);
mF.y = (float) (height - _sin * mMovement.x);
// If the x position of A is above half of the page we are still not
// folding the upper-right edge and so E and D are equal.
if (mA.x > width / 2) {
mE.x = mD.x;
mE.y = mD.y;
} else {
// So get E
mE.x = (float) (mD.x + _cos * (width - mD.x));
mE.y = (float) -(_sin * (width - mD.x));
}
}
/**
* Calculate the dynamic effect, that one that follows the users finger
*/
private void doDynamicCurl() {
int width = getWidth();
int height = getHeight();
// F will follow the finger, we add a small displacement
// So that we can see the edge
mF.x = width - mMovement.x + 0.1f;
mF.y = height - mMovement.y + 0.1f;
// Set min points
if (mA.x == 0) {
mF.x = Math.min(mF.x, mOldF.x);
mF.y = Math.max(mF.y, mOldF.y);
}
// Get diffs
float deltaX = width - mF.x;
float deltaY = height - mF.y;
float BH = (float) (Math.sqrt(deltaX * deltaX + deltaY * deltaY) / 2);
double tangAlpha = deltaY / deltaX;
double alpha = Math.atan(deltaY / deltaX);
double _cos = Math.cos(alpha);
double _sin = Math.sin(alpha);
mA.x = (float) (width - (BH / _cos));
mA.y = height;
mD.y = (float) (height - (BH / _sin));
mD.x = width;
mA.x = Math.max(0, mA.x);
if (mA.x == 0) {
mOldF.x = mF.x;
mOldF.y = mF.y;
}
// Get W
mE.x = mD.x;
mE.y = mD.y;
// Correct
if (mD.y < 0) {
mD.x = width + (float) (tangAlpha * mD.y);
mE.y = 0;
mE.x = width + (float) (Math.tan(2 * alpha) * mD.y);
}
}
/**
* Swap between the fore and back-ground.
*/
#Deprecated
private void SwapViews() {
Bitmap temp = mForeground;
mForeground = mBackground;
mBackground = temp;
}
/**
* Swap to next view
*/
private void nextView() {
MySQLiteHelper SqlLiteInstance = new MySQLiteHelper(hesham);
SqlLiteInstance.insertForTest("تايتل", "لبلب", "ثثث");
SqlLiteInstance.insertForTest("تايتل التاني", "5555", "5555");
SqlLiteInstance.insertForTest("التالت", "66666", "66666");
int foreIndex = mIndex + 1;
Cursor myDataBase = SqlLiteInstance.getCurrentPageData(1);
if (myDataBase.moveToFirst() && myDataBase.getCount() >= 1) {
do {
textViewContent.setText(myDataBase.getString(0));
} while (myDataBase.moveToNext());
}
if (foreIndex >= mPages.size()) {
foreIndex = 0;
}
int backIndex = foreIndex + 1;
if (backIndex >= mPages.size()) {
backIndex = 0;
}
mIndex = foreIndex;
setViews(foreIndex, backIndex);
}
/**
* Swap to previous view
*/
private void previousView() {
int backIndex = mIndex;
int foreIndex = backIndex - 1;
if (foreIndex < 0) {
foreIndex = mPages.size() - 1;
}
mIndex = foreIndex;
setViews(foreIndex, backIndex);
}
/**
* Set current fore and background
*
* #param foreground
* - Foreground view index
* #param background
* - Background view index
*/
private void setViews(int foreground, int background) {
mForeground = mPages.get(foreground);
mBackground = mPages.get(background);
}
// ---------------------------------------------------------------
// Drawing methods
// ---------------------------------------------------------------
#Override
protected void onDraw(Canvas canvas) {
// Always refresh offsets
mCurrentLeft = getLeft();
mCurrentTop = getTop();
// Translate the whole canvas
// canvas.translate(mCurrentLeft, mCurrentTop);
// We need to initialize all size data when we first draw the view
if (!bViewDrawn) {
bViewDrawn = true;
onFirstDrawEvent(canvas);
}
canvas.drawColor(Color.WHITE);
// Curl pages
// DoPageCurl();
// TODO: This just scales the views to the current
// width and height. We should add some logic for:
// 1) Maintain aspect ratio
// 2) Uniform scale
// 3) ...
Rect rect = new Rect();
rect.left = 0;
rect.top = 0;
rect.bottom = getHeight();
rect.right = getWidth();
// First Page render
Paint paint = new Paint();
// Draw our elements
drawForeground(canvas, rect, paint);
drawBackground(canvas, rect, paint);
drawCurlEdge(canvas);
// Draw any debug info once we are done
if (bEnableDebugMode)
drawDebug(canvas);
// Check if we can re-enable input
if (bEnableInputAfterDraw) {
bBlockTouchInput = false;
bEnableInputAfterDraw = false;
}
// Restore canvas
// canvas.restore();
}
/**
* Called on the first draw event of the view
*
* #param canvas
*/
protected void onFirstDrawEvent(Canvas canvas) {
mFlipRadius = getWidth();
ResetClipEdge();
DoPageCurl();
}
/**
* Draw the foreground
*
* #param canvas
* #param rect
* #param paint
*/
private void drawForeground(Canvas canvas, Rect rect, Paint paint) {
canvas.drawBitmap(mForeground, null, rect, paint);
// Draw the page number (first page is 1 in real life :D
// there is no page number 0 hehe)
drawPageNum(canvas, mIndex);
}
/**
* Create a Path used as a mask to draw the background page
*
* #return
*/
private Path createBackgroundPath() {
Path path = new Path();
path.moveTo(mA.x, mA.y);
path.lineTo(mB.x, mB.y);
path.lineTo(mC.x, mC.y);
path.lineTo(mD.x, mD.y);
path.lineTo(mA.x, mA.y);
return path;
}
/**
* Draw the background image.
*
* #param canvas
* #param rect
* #param paint
*/
private void drawBackground(Canvas canvas, Rect rect, Paint paint) {
Path mask = createBackgroundPath();
// Save current canvas so we do not mess it up
canvas.save();
canvas.clipPath(mask);
canvas.drawBitmap(mBackground, null, rect, paint);
// Draw the page number (first page is 1 in real life :D
// there is no page number 0 hehe)
drawPageNum(canvas, mIndex);
canvas.restore();
}
/**
* Creates a path used to draw the curl edge in.
*
* #return
*/
private Path createCurlEdgePath() {
Path path = new Path();
path.moveTo(mA.x, mA.y);
path.lineTo(mD.x, mD.y);
path.lineTo(mE.x, mE.y);
path.lineTo(mF.x, mF.y);
path.lineTo(mA.x, mA.y);
return path;
}
/**
* Draw the curl page edge
*
* #param canvas
*/
private void drawCurlEdge(Canvas canvas) {
Path path = createCurlEdgePath();
canvas.drawPath(path, mCurlEdgePaint);
}
/**
* Draw page num (let this be a bit more custom)
*
* #param canvas
* #param pageNum
*/
private void drawPageNum(Canvas canvas, int pageNum) {
mTextPaint.setColor(Color.WHITE);
String pageNumText = "- " + pageNum + " -";
drawCentered(canvas, pageNumText,
canvas.getHeight() - mTextPaint.getTextSize() - 5, mTextPaint,
mTextPaintShadow);
}
// ---------------------------------------------------------------
// Debug draw methods
// ---------------------------------------------------------------
/**
* Draw a text with a nice shadow
*/
public static void drawTextShadowed(Canvas canvas, String text, float x,
float y, Paint textPain, Paint shadowPaint) {
canvas.drawText(text, x - 1, y, shadowPaint);
canvas.drawText(text, x, y + 1, shadowPaint);
canvas.drawText(text, x + 1, y, shadowPaint);
canvas.drawText(text, x, y - 1, shadowPaint);
canvas.drawText(text, x, y, textPain);
}
/**
* Draw a text with a nice shadow centered in the X axis
*
* #param canvas
* #param text
* #param y
* #param textPain
* #param shadowPaint
*/
public static void drawCentered(Canvas canvas, String text, float y,
Paint textPain, Paint shadowPaint) {
float posx = (canvas.getWidth() - textPain.measureText(text)) / 2;
drawTextShadowed(canvas, text, posx, y, textPain, shadowPaint);
}
/**
* Draw debug info
*
* #param canvas
*/
private void drawDebug(Canvas canvas) {
float posX = 10;
float posY = 20;
Paint paint = new Paint();
paint.setStrokeWidth(5);
paint.setStyle(Style.STROKE);
paint.setColor(Color.BLACK);
canvas.drawCircle(mOrigin.x, mOrigin.y, getWidth(), paint);
paint.setStrokeWidth(3);
paint.setColor(Color.RED);
canvas.drawCircle(mOrigin.x, mOrigin.y, getWidth(), paint);
paint.setStrokeWidth(5);
paint.setColor(Color.BLACK);
canvas.drawLine(mOrigin.x, mOrigin.y, mMovement.x, mMovement.y, paint);
paint.setStrokeWidth(3);
paint.setColor(Color.RED);
canvas.drawLine(mOrigin.x, mOrigin.y, mMovement.x, mMovement.y, paint);
posY = debugDrawPoint(canvas, "A", mA, Color.RED, posX, posY);
posY = debugDrawPoint(canvas, "B", mB, Color.GREEN, posX, posY);
posY = debugDrawPoint(canvas, "C", mC, Color.BLUE, posX, posY);
posY = debugDrawPoint(canvas, "D", mD, Color.CYAN, posX, posY);
posY = debugDrawPoint(canvas, "E", mE, Color.YELLOW, posX, posY);
posY = debugDrawPoint(canvas, "F", mF, Color.LTGRAY, posX, posY);
posY = debugDrawPoint(canvas, "Mov", mMovement, Color.DKGRAY, posX,
posY);
posY = debugDrawPoint(canvas, "Origin", mOrigin, Color.MAGENTA, posX,
posY);
posY = debugDrawPoint(canvas, "Finger", mFinger, Color.GREEN, posX,
posY);
// Draw some curl stuff (Just some test)
/*
* canvas.save(); Vector2D center = new
* Vector2D(getWidth()/2,getHeight()/2);
* //canvas.rotate(315,center.x,center.y);
*
* // Test each lines //float radius = mA.distance(mD)/2.f; //float
* radius = mA.distance(mE)/2.f; float radius = mA.distance(mF)/2.f;
* //float radius = 10; float reduction = 4.f; RectF oval = new RectF();
* oval.top = center.y-radius/reduction; oval.bottom =
* center.y+radius/reduction; oval.left = center.x-radius; oval.right =
* center.x+radius; canvas.drawArc(oval, 0, 360, false, paint);
* canvas.restore(); /*
*/
}
private float debugDrawPoint(Canvas canvas, String name, Vector2D point,
int color, float posX, float posY) {
return debugDrawPoint(canvas, name + " " + point.toString(), point.x,
point.y, color, posX, posY);
}
private float debugDrawPoint(Canvas canvas, String name, float X, float Y,
int color, float posX, float posY) {
mTextPaint.setColor(color);
drawTextShadowed(canvas, name, posX, posY, mTextPaint, mTextPaintShadow);
Paint paint = new Paint();
paint.setStrokeWidth(5);
paint.setColor(color);
canvas.drawPoint(X, Y, paint);
return posY + 15;
}
}
xml code :
<RelativeLayout
android:id="#+id/game_layout"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<com.mystictreegames.pagecurl.PageCurlView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/dcgpagecurlPageCurlView1"
android:background="#drawable/facebook">
</com.mystictreegames.pagecurl.PageCurlView>
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_centerVertical="true"
android:text="جوهر كون المرء انه انسان لا يسعى الى الكمال"/>
log error:
FATAL EXCEPTION: main
E/AndroidRuntime(2497): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mystictreegames.pagecurl/com.mystictreegames.pagecurl.StandaloneExample}: android.view.InflateException: Binary XML file line #13: Error inflating class com.mystictreegames.pagecurl.PageCurlView

In the init() of the PageCurlView class, you are inflating R.layout.standalone_example. Objects are added in a circular manner (R.layout.standalone_example has PageCurlView which has R.layout.standalone_example which has ...).

Printable prints BufferedImage with incorrect size

So yeah what I am trying here is printing a BufferedImage, all works just fine until you see the outcome. The outcome is to big, the print is to large and doesn't it scales up everything when printing for some reason.
I used ((MM * DPI)/25,4) to calculate the correct pixel length according to paper size from Millimeters but when I print it its to big.
This is the code I wrote for it:
package frik.main;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.awt.print.PageFormat;
import java.awt.print.Printable;
import java.awt.print.PrinterException;
import java.awt.print.PrinterJob;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.UIManager;
import java.awt.event.*;
import javax.swing.*;
import frik.data.Config;
import frik.utils.ImgUtil;
public class Previewer implements Config, Printable, ActionListener{
private JFrame Frame;
private JPanel ImagePanel;
private JLabel PicLabel;
private JButton PrintButton;
private static BufferedImage before;
private static boolean Scaled;
public Previewer(BufferedImage Image, boolean scaled){
this.before = Image;
this.Scaled = scaled;
loop();
}
public int print(Graphics g, PageFormat pf, int page) throws PrinterException{
if (page > 0) {
return Printable.NO_SUCH_PAGE;
}
Graphics2D g2d = (Graphics2D)g;
g2d.translate(pf.getImageableX(), pf.getImageableY());
g.drawImage(0, 0, null);
return Printable.PAGE_EXISTS;
}
public void actionPerformed(ActionEvent e){
PrinterJob job = PrinterJob.getPrinterJob();
job.setPrintable(this);
boolean ok = job.printDialog();
if (ok) {
try {
job.print();
} catch (PrinterException ex) {
JOptionPane.showMessageDialog(null, "The Printjob did not successfully complete.", "Print Failure.", JOptionPane.WARNING_MESSAGE);
}
}
}
public void loop(){
UIManager.put("swing.boldMetal", Boolean.FALSE);
Frame = new JFrame("Mold Preview");
ImagePanel = new JPanel();
PrintButton = new JButton("Print Mold");
Frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {System.exit(0);}
});
if(Scaled){
PicLabel = new JLabel(new ImageIcon(ImgUtil.scaleImage(PAPER_WIDTH / 3, PAPER_HEIGHT / 3, before)));
}else if (!Scaled){
PicLabel = new JLabel(new ImageIcon(before));
}
ImagePanel.setBackground(Color.orange);
ImagePanel.add(PicLabel);
Frame.add("Center", ImagePanel);
PrintButton.addActionListener(this);
Frame.add("North", PrintButton);
Frame.pack();
Frame.setVisible(true);
Frame.setResizable(false);
}
public static void main(String args[]){
new Previewer(before, Scaled);
//////////////////////////////
}
}
So if someone could help me scale the image before printing it according to the printers scale factor, because I am assuming the printers DPI is causing this, so that the image is the exact size in Millimeters when printed exact to the size input in pixels.
That would be great.

I'm not sure if this is an answer per se, but it solves one of the "niggly" issues I'm having.
I think the problem I have is you don't have a source DPI, so it's not possible to convert from one context to another. Let's say you have a image of 200x200, what does that actually mean?
Without the DPI it's meaningless. If the image is 300dpi, then we could use pixels / dpi = inches = 200 / 72 = 0.667 inches. Then we can convert that to pixels # 72dpi using inches * dpi = 0.667 * 72 = 48
Now, the question the becomes, how do I get the DPI of an image. That's not nearly as easy as it sounds...
import core.ui.UIUtilities;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.stream.ImageInputStream;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
public class TestDPI {
public static final float INCH_PER_MM = 25.4f;
public static void main(String[] args) {
File imageFile = new File("/path/to/your/image");
ImageInputStream iis = null;
try {
iis = ImageIO.createImageInputStream(imageFile);
Iterator<ImageReader> readers = ImageIO.getImageReaders(iis);
if (!readers.hasNext()) {
throw new IOException("Bad format, no readers");
}
ImageReader reader = readers.next();
reader.setInput(iis);
IIOMetadata meta = reader.getImageMetadata(0);
Node root = meta.getAsTree("javax_imageio_1.0");
NodeList nl = root.getChildNodes();
float horizontalPixelSize = 0;
float verticalPixelSize = 0;
for (int index = 0; index < nl.getLength(); index++) {
Node child = nl.item(index);
if ("Dimension".equals(child.getNodeName())) {
NodeList dnl = child.getChildNodes();
for (int inner = 0; inner < dnl.getLength(); inner++) {
child = dnl.item(inner);
if ("HorizontalPixelSize".equals(child.getNodeName())) {
horizontalPixelSize = Float.parseFloat(child.getAttributes().getNamedItem("value").getNodeValue());
} else if ("VerticalPixelSize".equals(child.getNodeName())) {
verticalPixelSize = Float.parseFloat(child.getAttributes().getNamedItem("value").getNodeValue());
}
}
}
}
// As "I" understand it. The horizontalPixelSize and verticalPixelSize
// are the number of millimeters per pixel that should be occupied...
System.out.println((INCH_PER_MM / horizontalPixelSize) + "x" + (INCH_PER_MM / verticalPixelSize));
} catch (IOException ex) {
ex.printStackTrace();
} finally {
try {
iis.close();
} catch (Exception e) {
}
}
}
}
Update with preview example
This example basically uses the images own DPI and a target DPI to produce a "print preview"
My test image is 1667x1609 # 300dpi
300dpi test...
Original size = 1667x1609
cmSize = 14.11396110802889x13.622893474996092
Target (pixel) size = 1667x1609
72dpi test...
Original size = 1667x1609
cmSize = 14.11396110802889x13.622893474996092
Target (pixel) size = 400x386
import static core.ui.ImageUtilities.getScaleFactor;
import static core.ui.ImageUtilities.getScaleFactorToFit;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Transparency;
import java.awt.geom.Line2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.stream.ImageInputStream;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
public class TestPrintPreview {
public static void main(String[] args) {
new TestPrintPreview();
}
public TestPrintPreview() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
File imageFile = new File("C:\\hold\\thumbnails\\RentAZilla-300dpi.png");
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new JScrollPane(new PreviewPane(imageFile, 300)));
frame.setSize(400, 400);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
// The size of an A4 sheet in CMs
public static final double[] A4_PAPER_SIZE = new double[]{21.0, 29.7};
// The number of CMs per Inch
public static final double CM_PER_INCH = 0.393700787d;
// The number of Inches per CMs
public static final double INCH_PER_CM = 2.545d;
// The numer of Inches per mm's
public static final double INCH_PER_MM = 25.45d;
public class PreviewPane extends JPanel {
private BufferedImage img;
private float targetDPI;
private BufferedImage gridBackground;
public PreviewPane(File imageFile, float outputDPI) {
// This determines the output DPI we want...
targetDPI = outputDPI;
try {
// Get the DPI from the image...
double[] imgDPI = getDPI(imageFile);
// Read the image
img = ImageIO.read(imageFile);
// Output the original size...
System.out.println("Original size = " + img.getWidth() + "x" + img.getHeight());
// Calculate the size of the image in cm's
double cmWidth = pixelsToCms(img.getWidth(), imgDPI[0]);
double cmHeight = pixelsToCms(img.getHeight(), imgDPI[1]);
System.out.println("cmSize = " + cmWidth + "x" + cmHeight);
// Calculate the new image size based on the target DPI and
// the cm size of the image...
int imgWidth = (int) Math.round(cmsToPixel(cmWidth, targetDPI));
int imgHeight = (int) Math.round(cmsToPixel(cmHeight, targetDPI));
System.out.println("Target size = " + imgWidth + "x" + imgHeight);
// Create a scaled instance of the image to fit within the
// target boundries
img = getScaledInstanceToFit(img, new Dimension(imgWidth, imgHeight));
} catch (IOException ex) {
Logger.getLogger(TestPrintPreview.class.getName()).log(Level.SEVERE, null, ex);
}
setBackground(Color.WHITE);
}
#Override
public Dimension getPreferredSize() {
// Return the size of the component based on the size of
// an A4 sheet of paper and the target DPI
return new Dimension(
(int) Math.round(cmsToPixel(A4_PAPER_SIZE[0], targetDPI)),
(int) Math.round(cmsToPixel(A4_PAPER_SIZE[1], targetDPI)));
}
/**
* Generates a grid of 1x1 cm cells. This is used to allow you
* to compare the differences of different DPI and ensure that the
* output is what you are expecting...
* #return
*/
protected BufferedImage getGridBackground() {
if (gridBackground == null) {
// Calculate the width and height we need...
int width = (int) Math.round(cmsToPixel(A4_PAPER_SIZE[0], targetDPI));
int height = (int) Math.round(cmsToPixel(A4_PAPER_SIZE[1], targetDPI));
// Create the grid...
gridBackground = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = gridBackground.createGraphics();
// Calculate the size of each cell (1cm square)
double cmAsPixel = cmsToPixel(1, targetDPI);
float xPos = 0;
float yPos = 0;
g2d.setColor(new Color(225, 0, 0, 128));
int count = 0;
Font font = g2d.getFont();
g2d.setFont(font.deriveFont(8f));
FontMetrics fm = g2d.getFontMetrics();
// Draw the horizontal lines
while (xPos < gridBackground.getWidth()) {
g2d.draw(new Line2D.Float(xPos, 0, xPos, gridBackground.getHeight()));
// Add the text markers...
String text = (count++) + "cm";
float x = xPos - fm.stringWidth(text);
g2d.drawString(text, x, fm.getAscent());
xPos += cmAsPixel;
}
// Draw the vertical lines
count = 0;
while (yPos < gridBackground.getHeight()) {
g2d.draw(new Line2D.Float(0, yPos, gridBackground.getWidth(), yPos));
// Add the text markers
String text = (count++) + "cm";
float y = (yPos - fm.getHeight()) + fm.getAscent();
g2d.drawString(text, 0, y);
yPos += cmAsPixel;
}
g2d.dispose();
}
return gridBackground;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
// Paint the image...
g2d.drawImage(img, 0, 0, this);
// Paint the grid...
g2d.drawImage(getGridBackground(), 0, 0, this);
g2d.dispose();
}
}
/**
* Converts the given pixels to cm's based on the supplied DPI
* #param pixels
* #param dpi
* #return
*/
public static double pixelsToCms(double pixels, double dpi) {
return inchesToCms(pixels / dpi);
}
/**
* Converts the given cm's to pixels based on the supplied DPI
* #param cms
* #param dpi
* #return
*/
public static double cmsToPixel(double cms, double dpi) {
return cmToInches(cms) * dpi;
}
/**
* Converts the given cm's to inches
* #param cms
* #return
*/
public static double cmToInches(double cms) {
return cms * CM_PER_INCH;
}
/**
* Converts the given inches to cm's
* #param inch
* #return
*/
public static double inchesToCms(double inch) {
return inch * INCH_PER_CM;
}
/**
* Gets the DPI for the specified image. This does return the horizontal
* and vertical DPI, but you could conceivably use just use one of the values
* #param imageFile
* #return
* #throws IOException
*/
public double[] getDPI(File imageFile) throws IOException {
double[] dpi = new double[]{72, 72};
ImageInputStream iis = null;
try {
iis = ImageIO.createImageInputStream(imageFile);
Iterator<ImageReader> readers = ImageIO.getImageReaders(iis);
if (!readers.hasNext()) {
throw new IOException("Bad format, no readers");
}
ImageReader reader = readers.next();
reader.setInput(iis);
IIOMetadata meta = reader.getImageMetadata(0);
Node root = meta.getAsTree("javax_imageio_1.0");
NodeList nl = root.getChildNodes();
float horizontalPixelSize = 0;
float verticalPixelSize = 0;
for (int index = 0; index < nl.getLength(); index++) {
Node child = nl.item(index);
if ("Dimension".equals(child.getNodeName())) {
NodeList dnl = child.getChildNodes();
for (int inner = 0; inner < dnl.getLength(); inner++) {
child = dnl.item(inner);
if ("HorizontalPixelSize".equals(child.getNodeName())) {
horizontalPixelSize = Float.parseFloat(child.getAttributes().getNamedItem("value").getNodeValue());
} else if ("VerticalPixelSize".equals(child.getNodeName())) {
verticalPixelSize = Float.parseFloat(child.getAttributes().getNamedItem("value").getNodeValue());
}
}
}
}
dpi = new double[]{(INCH_PER_MM / horizontalPixelSize), (INCH_PER_MM / verticalPixelSize)};
} finally {
try {
iis.close();
} catch (Exception e) {
}
}
return dpi;
}
/**
* Returns a scaled instance of the image to fit within the specified
* area. This means that the image is guaranteed to be <= size.width and
* <= size.height
* #param img
* #param size
* #return
*/
public static BufferedImage getScaledInstanceToFit(BufferedImage img, Dimension size) {
double scaleFactor = getScaleFactorToFit(img, size);
return getScaledInstance(img, scaleFactor);
}
public static double getScaleFactorToFit(BufferedImage img, Dimension size) {
double dScale = 1;
if (img != null) {
int imageWidth = img.getWidth();
int imageHeight = img.getHeight();
dScale = getScaleFactorToFit(new Dimension(imageWidth, imageHeight), size);
}
return dScale;
}
/**
* Returns the required scale factor to fit the original size into the toFit
* size.
* #param original
* #param toFit
* #return
*/
public static double getScaleFactorToFit(Dimension original, Dimension toFit) {
double dScale = 1d;
if (original != null && toFit != null) {
double dScaleWidth = getScaleFactor(original.width, toFit.width);
double dScaleHeight = getScaleFactor(original.height, toFit.height);
dScale = Math.min(dScaleHeight, dScaleWidth);
}
return dScale;
}
/**
* Returns the scale factor required to go from the master size to the
* target size
* #param iMasterSize
* #param iTargetSize
* #return
*/
public static double getScaleFactor(int iMasterSize, int iTargetSize) {
return (double) iTargetSize / (double) iMasterSize;
}
/**
* Returns a scaled instance of the image based on the supplied scale factor.
*
* The images width and height are multiplied by the supplied scale factor
* #param img
* #param dScaleFactor
* #return
*/
protected static BufferedImage getScaledInstance(BufferedImage img, double dScaleFactor) {
BufferedImage imgScale = img;
int iImageWidth = (int) Math.round(img.getWidth() * dScaleFactor);
int iImageHeight = (int) Math.round(img.getHeight() * dScaleFactor);
if (dScaleFactor <= 1.0d) {
imgScale = getScaledDownInstance(img, iImageWidth, iImageHeight);
} else {
imgScale = getScaledUpInstance(img, iImageWidth, iImageHeight);
}
return imgScale;
}
/**
* Scales the specified image down to be less then equal to the target width
* and height.
*
* The image is scaled using a divide an conquer approach to provide
* the best scaling possible
* #param img
* #param targetWidth
* #param targetHeight
* #return
*/
protected static BufferedImage getScaledDownInstance(BufferedImage img,
int targetWidth,
int targetHeight) {
int type = (img.getTransparency() == Transparency.OPAQUE)
? BufferedImage.TYPE_INT_RGB : BufferedImage.TYPE_INT_ARGB;
BufferedImage ret = (BufferedImage) img;
if (targetHeight > 0 || targetWidth > 0) {
int w, h;
w = img.getWidth();
h = img.getHeight();
do {
if (w > targetWidth) {
w /= 2;
if (w < targetWidth) {
w = targetWidth;
}
}
if (h > targetHeight) {
h /= 2;
if (h < targetHeight) {
h = targetHeight;
}
}
BufferedImage tmp = new BufferedImage(Math.max(w, 1), Math.max(h, 1), type);
Graphics2D g2 = tmp.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2.drawImage(ret, 0, 0, w, h, null);
g2.dispose();
ret = tmp;
} while (w != targetWidth || h != targetHeight);
} else {
ret = new BufferedImage(1, 1, type);
}
return ret;
}
/**
/**
* Scales the specified image up
*
* The image is scaled using a divide an conquer approach to provide
* the best scaling possible
* #param img
* #param targetWidth
* #param targetHeight
* #return
*/
protected static BufferedImage getScaledUpInstance(BufferedImage img,
int targetWidth,
int targetHeight) {
int type = BufferedImage.TYPE_INT_ARGB;
BufferedImage ret = (BufferedImage) img;
int w, h;
w = img.getWidth();
h = img.getHeight();
do {
if (w < targetWidth) {
w *= 2;
if (w > targetWidth) {
w = targetWidth;
}
}
if (h < targetHeight) {
h *= 2;
if (h > targetHeight) {
h = targetHeight;
}
}
BufferedImage tmp = new BufferedImage(w, h, type);
Graphics2D g2 = tmp.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2.drawImage(ret, 0, 0, w, h, null);
g2.dispose();
ret = tmp;
tmp = null;
} while (w != targetWidth || h != targetHeight);
return ret;
}
}

How to make a sprite spiral to the center (in Java but if you know a formula, it would help too)

I'm making a game in java where enemy sprites spiral to the center and damage the main tower. The only thing I'm having problems with is the formula to make the sprite spiral. All I found on the internet it this: http://scratch.mit.edu/projects/1439249/
That is sort of what I want to do but I want to make them spiral to a point from outside the JFrame, not from a point within the JFrame.
I am in Secondary 4 and I don't have to much knowledge about such formulas yet and sorry if I have problems understanding the formulas. Thanks in advance!

One simple way of making a sprite appear to spiral is to pretend that it is attached to an arm, like the hand of a clock, that rotates around the center of the spiral. As that arm rotates, slowly move the sprite down the arm towards the center. What you end up with is a classic Archimedan Spiral
I can mock up some code for you, but that's going to take a few minutes.
Okay, here's the code.
public static double getArmX(double length, double angle) {
return Math.cos(angle) * length;
}
public static double getArmY(double length, double angle) {
return Math.sin(angle) * length;
}
These are the core of the math. They return the x and y values of an entity that is at the specified distance from the center (length) and angle from the center (angle).
Now, I don't know how you have your code set up, but lets pretend we have a double named spiralProgress that represents how far into its spiral your entity is. At spiralProgress == 0, the entity is just starting, and at spiralProgress == 1, the entity is at the center.
Here is what the code to get the x and y for the entity would look like:
double startingRadius = 64;
double rotations = 10;
double x = getArmX(startingRadius * (1-t), t * rotations * Math.PI * 2);
double y = getArmY(startingRadius * (1-t), t * rotations * Math.PI * 2);
In that snippet, startingRadius is how many units (pixels, if thats what x and y means in your program), the entity should start away from the center, and rotations is how many times the entity should loop around the center before reaching it.
The coordinates this returns are for a spiral around {0, 0}, so if you want to spiral around some other point, say {screenWidth / 2, screenHeight / 2}, you'd add screenWidth / 2 to x and screenHeight / 2 to y.
Here is a full Java program that demonstrates this math. Click the mouse anywhere in the window to reset the spiral.
package net.eonz.stackoverflow.spiral;
import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.BufferStrategy;
import javax.swing.JFrame;
public class Game extends Canvas implements Runnable, MouseListener {
private static final long serialVersionUID = 1L;
public static final String NAME = "untitled";
public static final int HEIGHT = 600;
public static final int WIDTH = 600;
public static final int SCALE = 1;
private boolean running = false;
public void start() {
running = true;
new Thread(this).start();
this.addMouseListener(this);
}
public void stop() {
running = false;
}
public void run() {
long last = System.currentTimeMillis();
while (running) {
long now = System.currentTimeMillis();
double dt = (now - last) / 1000.0;
last = now;
update(dt);
render();
}
}
double t = 0;
public void update(double dt) {
t += dt / 16;
if (t > 1)
t = 1;
}
public void render() {
BufferStrategy bs = getBufferStrategy();
if (bs == null) {
createBufferStrategy(3);
return;
}
Graphics g = bs.getDrawGraphics();
g.setColor(Color.white);
g.fillRect(0, 0, this.getWidth(), this.getHeight());
/* SPIRAL MATH IS HERE */
double startingRadius = this.getHeight() * 0.40;
double rotations = 10;
double x = getArmX(startingRadius * (1 - t), t * rotations * Math.PI
* 2);
double y = getArmY(startingRadius * (1 - t), t * rotations * Math.PI
* 2);
g.setColor(Color.black);
g.fillRect((int) (x - 8) + this.getWidth() / 2,
(int) (y - 8) + this.getHeight() / 2, 16, 16);
/* END SPIRAL MATH */
g.dispose();
bs.show();
}
public static double getArmX(double length, double angle) {
return Math.cos(angle) * length;
}
public static double getArmY(double length, double angle) {
return Math.sin(angle) * length;
}
#Override
public void mouseClicked(MouseEvent e) {
this.t = 0;
}
#Override
public void mousePressed(MouseEvent e) {
}
#Override
public void mouseReleased(MouseEvent e) {
}
#Override
public void mouseEntered(MouseEvent e) {
}
#Override
public void mouseExited(MouseEvent e) {
}
public static void main(String[] args) {
Game game = new Game();
game.setMinimumSize(new Dimension(WIDTH * SCALE, HEIGHT * SCALE));
game.setMaximumSize(new Dimension(WIDTH * SCALE, HEIGHT * SCALE));
game.setPreferredSize(new Dimension(WIDTH * SCALE, HEIGHT * SCALE));
JFrame frame = new JFrame(Game.NAME);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(game, BorderLayout.CENTER);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setResizable(false);
frame.setVisible(true);
game.start();
}
}

I am new to java programming too and as part of my course I recently had to program a spiral.
Here is the solution file from my course.
This will draw a simple spiral.
I hope this helps you. It also has comments to help you understand what is happening.
enjoy
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JPanel;
public class DrawSpiral2 extends JPanel
{
// draws a square shape that continually spirals outward
public void paintComponent( Graphics g )
{
super.paintComponent( g );
g.setColor( Color.GREEN );
// draw a green spiral
int x = getWidth() / 2;
// x coordinate of upperleft corner
int y = getHeight() / 2;
// y coordinate of upperleft corner
int radiusStep = 20;
// distance the radius changes
int diameter = 0; // diameter of the arc
int arc = 180; // amount and direction of arc to sweep
// draws individual lines in to form a spiral
for ( int i = 0; i < 20; i++ )
{
if ( i % 2 == 1 ) // move the x position every other repetition
x -= 2 * radiusStep;
y -= radiusStep; // move the y position
diameter += 2 * radiusStep; // increase the diameter
g.drawArc( x, y, diameter, diameter, 0, arc );
// draw the arc
arc = -arc; // reverse the direction of the arc
} // end for
} // end method paintComponent
} // end class DrawSpiral2
Here is the test file.
public class DrawSpiralTest2
{
public static void main( String args[] )
{
DrawSpiral2 panel = new DrawSpiral2();
JFrame application = new JFrame();
application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
application.add( panel );
application.setSize( 300, 300 );
application.setVisible( true );
} // end main
} // end class DrawSpiralTest2

Java - Slick - Fill Rectangle on Click

I am trying to fill a rectangle on the nearest 10th pixel with a 50x50 size. Whenever this code executes, it shows me the numbers in the syso so I know the locations are being calculated correctly. However, the rectangle does not appear. I have a grid drawn but the squares aren't being drawn correctly. What am I doing wrong? I'm not getting any Stack Traces from errors or something like that...
if(gc.getInput().isMousePressed(0)){
float f1 = (float) Math.ceil(gc.getInput().getMouseX() / 16 * 10);
float f2 = (float) Math.ceil(gc.getInput().getMouseY() / 12 * 10);
gc.getGraphics().fillRect(f1, f2, 50, 50);
System.out.println("Filled: " + f1 + "x" + f2);
}

This is my solution, based on your code:
package game;
import entity.Block;
import org.newdawn.slick.Color;
import org.newdawn.slick.GameContainer;
import org.newdawn.slick.Graphics;
import org.newdawn.slick.SlickException;
import org.newdawn.slick.geom.Rectangle;
import org.newdawn.slick.state.BasicGameState;
import org.newdawn.slick.state.StateBasedGame;
import world.Camera;
import world.World;
import java.util.ArrayList;
import java.util.List;
public class TestState extends BasicGameState {
/**
* This variable sets
* the gird size, and the block's
* size.
*/
private final int size = 50;
/**
* This list contains/stores the blocks
* who going to be rendered.
*/
private final List<Block> blocks = new ArrayList<>();
#Override
public int getID() {
return 0;
}
#Override
public void init(GameContainer gc, StateBasedGame sbg) throws SlickException {
}
#Override
public void render(GameContainer gc, StateBasedGame sbg, Graphics g) throws SlickException {
/**
* DRAW THE GRID
*
* This can be confusing
* for the first look, but its logical.
*/
g.setColor(Color.white);
for (int i = 0; i < 50; i++) {
float y = i * size;
float x = 0;
g.drawLine(x, y, gc.getWidth(), y);
for (int i2 = 0; i2 < 50; i2++) {
float x2 = i2 * size;
g.drawLine(x2, y, x2, gc.getHeight());
}
}
// DRAW EACH BLOCKS (this is a for-each loop)
for (Block block : blocks) {
block.render(gc, g);
}
}
#Override
public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException {
// ADD NEW BLOCK IF MOUSE PRESSED
if (gc.getInput().isMouseButtonDown(0)) {
// get the x and y positions
float x = (float) Math.ceil(gc.getInput().getMouseX() / size * size);
float y = (float) Math.ceil(gc.getInput().getMouseY() / size * size);
/**
* The block class has a
* special constructor because
* I built it for my game.
* You should build your own.
*
* The block is *size by *size sized :D
* I mean the *size is the variable.
* Ohh, and it's uses the x & y positions.
*/
blocks.add(new Block(new World(new Camera()), new Camera(), new Rectangle(x, y, size, size)));
}
}
}
The output: