I code a mini Android game scenario inspired by Space Invaders and Moon Patrol. It is possible to shoot an alien horizontally (see above).
It is also possible to shoot an alien vertically (see below).
But adding aliens doesn't "scale", it will be very difficult to add for instance 15 aliens moving with respect to all possible collisions. The original space invaders and moon patrol solved this, is it possible to develop a different strategy than the one I am using? The exact movement of aliens is not important, only that it is "fun".
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.support.v4.view.MotionEventCompat;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import java.util.ArrayList;
import java.util.List;
public class ParallaxView extends SurfaceView implements Runnable {
List<Background> backgrounds;
private volatile boolean running;
private Thread gameThread = null;
// For drawing
private Paint paint;
private Canvas canvas;
private SurfaceHolder ourHolder;
// Holds a reference to the Activity
Context context;
// Control the fps
long fps = 60;
// Screen resolution
int screenWidth;
int screenHeight;
private void update() {
// Update all the background positions
for (Background bg : backgrounds) {
bg.update(fps);
}
}
ParallaxView(Context context, int screenWidth, int screenHeight) {
super(context);
this.context = context;
this.screenWidth = screenWidth;
this.screenHeight = screenHeight;
// Initialize our drawing objects
ourHolder = getHolder();
paint = new Paint();
// Initialize our array list
backgrounds = new ArrayList<>();
//load the background data into the Background objects and
// place them in our GameObject arraylist
backgrounds.add(new Background(
this.context,
screenWidth,
screenHeight,
"bg", 0, 120, 50));
backgrounds.add(new Background(
this.context,
screenWidth,
screenHeight,
"grass", 70, 110, 200));
// Add more backgrounds here
}
#Override
public void run() {
while (running) {
long startFrameTime = System.currentTimeMillis();
update();
if (j > 2000) {
j = -50;
k = 0;
}
if (o > 2000) {
o = -50;
l = 0;
}
draw();
// Calculate the fps this frame
long timeThisFrame = System.currentTimeMillis() - startFrameTime;
if (timeThisFrame >= 1) {
fps = 1000 / timeThisFrame;
}
}
}
int numberOfshots = 1;
int[] i = new int[200];
int j = 0;
int k = 0;
int l = 0;
int m = 0;
int o = 0;
boolean down = true;
long lastTurn = System.currentTimeMillis();
int xbuggy = 0;
int xbuggy2 = 0;
boolean down2 = true;
long lastTurn2 = System.currentTimeMillis();
long lastTurn3 = System.currentTimeMillis();
boolean jump = false;
boolean shoot = false;
int ind = 0;
private void draw() {
if (ourHolder.getSurface().isValid()) {
//First we lock the area of memory we will be drawing to
canvas = ourHolder.lockCanvas();
if (jump) {
xbuggy = xbuggy + 4;
}
if (shoot) {
xbuggy2 = xbuggy2 + 4;
}
if (System.currentTimeMillis() - lastTurn3 >= 1000) {
// Change direction here
jump = false;
lastTurn3 = System.currentTimeMillis();
xbuggy = 0;
}
//draw a background color
canvas.drawColor(Color.argb(255, 0, 0, 0));
// Draw the background parallax
drawBackground(0);
// Draw the rest of the game
paint.setTextSize(60);
paint.setColor(Color.argb(255, 255, 255, 255));
//canvas.drawText("MOONPATROL3000", 350, screenHeight / 100 * 5, paint);
int resID = context.getResources().getIdentifier("vehicle",
"drawable", context.getPackageName());
int alienResID = context.getResources().getIdentifier("object3_hdpi",
"drawable", context.getPackageName());
int alienResID2 = context.getResources().getIdentifier("object2_hdpi",
"drawable", context.getPackageName());
int alienResID3 = context.getResources().getIdentifier("object1_hdpi",
"drawable", context.getPackageName());
// Load the bitmap using the id
Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), resID);
Bitmap alienbitmap = BitmapFactory.decodeResource(context.getResources(), alienResID);
Bitmap alienbitmap2 = BitmapFactory.decodeResource(context.getResources(), alienResID2);
Bitmap alienbitmap3 = BitmapFactory.decodeResource(context.getResources(), alienResID3);
//paint.setTextSize(220);
for (int i1 = 0; i1 < numberOfshots; i1++) {
// if horizontal missile hits alien 0
if (java.lang.Math.abs(j - i[i1]) * 2 < (alienbitmap.getWidth() + 60) && java.lang.Math.abs(k +150+ screenHeight / 100 * 45 - (float) (screenHeight * 0.61)) * 2 < (alienbitmap.getHeight() + 60)) {
//y1[i2] = -random.nextInt(1000); // reset to new vertical position
//score += 1;
//onScoreListener.onScore(score);
Log.d("missile", "missile hit! ");
j=-200;
}
// if vertical missile hits alien 0
if (java.lang.Math.abs(j - 185) * 2 < (alienbitmap.getWidth() + 60) && java.lang.Math.abs(j + 150 + screenHeight / 100 * 45 - (screenHeight / 100 * 95 - i[i1] - xbuggy2)) * 2 < (alienbitmap.getHeight() + 60)) {
//y1[i2] = -random.nextInt(1000); // reset to new vertical position
//score += 1;
//onScoreListener.onScore(score);
Log.d("missile", "missile hit! ");
j=-200;
}
// if horizontal missile hits alien 1, right now this won't happen
if (java.lang.Math.abs(j - i[i1]) * 2 < (alienbitmap.getWidth() + 60) && java.lang.Math.abs(k +150+ screenHeight / 100 * 45 - (float) (screenHeight * 0.61)) * 2 < (alienbitmap.getHeight() + 60)) {
//y1[i2] = -random.nextInt(1000); // reset to new vertical position
//score += 1;
//onScoreListener.onScore(score);
Log.d("missile", "missile hit! ");
j=-200;
}
// if vertical missile hits alien 1
if (java.lang.Math.abs(o + 10 - 185) * 2 < (alienbitmap.getWidth() + 60) && java.lang.Math.abs(l + screenHeight / 100 * 25 - (screenHeight / 100 * 95 - i[i1] - xbuggy2)) * 2 < (alienbitmap.getHeight() + 60)) {
//y1[i2] = -random.nextInt(1000); // reset to new vertical position
//score += 1;
//onScoreListener.onScore(score);
Log.d("missile", "missile hit! ");
o=-200;
}
canvas.drawText("o", i[i1], (float) (screenHeight * 0.61), paint);
canvas.drawText("o", 185, screenHeight / 100 * 95 - i[i1] - xbuggy2, paint);
if (i1 == numberOfshots - 1 && i[i1] > screenWidth) {
if (numberOfshots > 0) numberOfshots--;
if (ind > 0) ind--;
}
}
if (System.currentTimeMillis() - lastTurn >= 2000) {
// Change direction here
down = !down;
lastTurn = System.currentTimeMillis();
}
if (System.currentTimeMillis() - lastTurn2 >= 7000) {
// Change direction here
down2 = !down2;
lastTurn2 = System.currentTimeMillis();
}
canvas.drawBitmap(alienbitmap, j, k +150+ screenHeight / 100 * 45, paint);
canvas.drawBitmap(alienbitmap2, o + 10, l + screenHeight / 100 * 25, paint);
//canvas.drawBitmap(alienbitmap3, j+20, k+screenHeight / 100 * 5, paint);
drawBackground(1);
canvas.drawBitmap(bitmap, 50, (float) (screenHeight * 0.5) - xbuggy, paint);
// Draw the foreground parallax
for (int n = 0; n < numberOfshots; n++)
i[n] = i[n] + 20;
j = j + 10;
o = o + 7;
if (!down)
k=k+2;
else
k=k-2;
if (!down2)
l++;
else
l--;
// Unlock and draw the scene
ourHolder.unlockCanvasAndPost(canvas);
}
}
// Clean up our thread if the game is stopped
public void pause() {
running = false;
try {
gameThread.join();
} catch (InterruptedException e) {
// Error
}
}
// Make a new thread and start it
// Execution moves to our run method
public void resume() {
running = true;
gameThread = new Thread(this);
gameThread.start();
}
private void drawBackground(int position) {
// Make a copy of the relevant background
Background bg = backgrounds.get(position);
// define what portion of images to capture and
// what coordinates of screen to draw them at
// For the regular bitmap
Rect fromRect1 = new Rect(0, 0, bg.width - bg.xClip, bg.height);
Rect toRect1 = new Rect(bg.xClip, bg.startY, bg.width, bg.endY);
// For the reversed background
Rect fromRect2 = new Rect(bg.width - bg.xClip, 0, bg.width, bg.height);
Rect toRect2 = new Rect(0, bg.startY, bg.xClip, bg.endY);
//draw the two background bitmaps
if (!bg.reversedFirst) {
canvas.drawBitmap(bg.bitmap, fromRect1, toRect1, paint);
canvas.drawBitmap(bg.bitmapReversed, fromRect2, toRect2, paint);
} else {
canvas.drawBitmap(bg.bitmap, fromRect2, toRect2, paint);
canvas.drawBitmap(bg.bitmapReversed, fromRect1, toRect1, paint);
}
}
// Because we call this from onTouchEvent, this code will be executed for both
// normal touch events and for when the system calls this using Accessibility
#Override
public boolean performClick() {
super.performClick();
launchMissile();
return true;
}
private void launchMissile() {
i[ind] = 350;
ind++;
xbuggy2 = 0;
shoot = true;
}
// event listener for when the user touches the screen
#Override
public boolean onTouchEvent(MotionEvent event) {
boolean gameOver = false;
//if (paused) {
// paused = false;
//}
int action = MotionEventCompat.getActionMasked(event);
int coordX = (int) event.getX();
int coordY = (int) event.getY();
Log.d("coordY", "coordY " + coordY);
if (coordX < 220 && xbuggy == 0 && action == MotionEvent.ACTION_MOVE) {
jump = true;
shoot = false;
lastTurn3 = System.currentTimeMillis();
return true; // do nothing
}
if (coordX > 219 && action == MotionEvent.ACTION_DOWN) {
numberOfshots++;
performClick();
return true;
}
return true;
}
}
Update
I have started to encapsulate the logic for the aliens according to the following.
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
public class Alien {
public Alien(){}
public Alien(Context context, String name) {
setAlienResID(context.getResources().getIdentifier("object3_hdpi",
"drawable", context.getPackageName()));
setAlienbitmap(BitmapFactory.decodeResource(context.getResources(), this.getAlienResID()));
}
public int getAlienResID() {
return alienResID;
}
public void setAlienResID(int alienResID) {
this.alienResID = alienResID;
}
public Bitmap getAlienbitmap() {
return alienbitmap;
}
public void setAlienbitmap(Bitmap alienbitmap) {
this.alienbitmap = alienbitmap;
}
public int getWidth() {
return width;
}
public void setWidth(int width) {
this.width = width;
}
public int getHeight() {
return height;
}
public void setHeight(int height) {
this.height = height;
}
int alienResID;
Bitmap alienbitmap;
int width;
int height;
}
public class AttackingAlien extends Alien {
public AttackingAlien(Context context, String name) {
super(context, name);
}
}
Update 2
I have changed the strategy. Now I am drawing a spaceship which is going to bomb the moon buggy.
The relevant code is
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.support.v4.view.MotionEventCompat;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import java.util.ArrayList;
import java.util.List;
public class ParallaxView extends SurfaceView implements Runnable {
List<Background> backgrounds;
private volatile boolean running;
private Thread gameThread = null;
// For drawing
private Paint paint;
private Canvas canvas;
private SurfaceHolder ourHolder;
// Holds a reference to the Activity
Context context;
// Control the fps
long fps = 60;
// Screen resolution
int screenWidth;
int screenHeight;
private void update() {
// Update all the background positions
for (Background bg : backgrounds) {
bg.update(fps);
}
}
ParallaxView(Context context, int screenWidth, int screenHeight) {
super(context);
this.context = context;
this.screenWidth = screenWidth;
this.screenHeight = screenHeight;
// Initialize our drawing objects
ourHolder = getHolder();
paint = new Paint();
// Initialize our array list
backgrounds = new ArrayList<>();
//load the background data into the Background objects and
// place them in our GameObject arraylist
backgrounds.add(new Background(
this.context,
screenWidth,
screenHeight,
"bg", 0, 120, 50));
backgrounds.add(new Background(
this.context,
screenWidth,
screenHeight,
"grass", 70, 110, 200));
// Add more backgrounds here
}
#Override
public void run() {
while (running) {
long startFrameTime = System.currentTimeMillis();
update();
if (j > 2000) {
j = -50;
k = 0;
}
if (o > 2000) {
o = -50;
l = 0;
}
draw();
// Calculate the fps this frame
long timeThisFrame = System.currentTimeMillis() - startFrameTime;
if (timeThisFrame >= 1) {
fps = 1000 / timeThisFrame;
}
}
}
int numberOfshots = 1;
int[] i = new int[200];
int j = 0;
int k = 0;
int l = 0;
int m = 0;
int o = 0;
boolean down = true;
long lastTurn = System.currentTimeMillis();
int xbuggy = 0;
int xbuggy2 = 0;
boolean down2 = true;
long lastTurn2 = System.currentTimeMillis();
long lastTurn3 = System.currentTimeMillis();
long lastTurn4 = System.currentTimeMillis();
boolean jump = false;
boolean shoot = false;
int ind = 0;
int numberOfAlienshots = 1;
int missileOffSetY = 0;
private void draw() {
if (ourHolder.getSurface().isValid()) {
//First we lock the area of memory we will be drawing to
canvas = ourHolder.lockCanvas();
if (jump) {
xbuggy = xbuggy + 4;
}
if (shoot) {
xbuggy2 = xbuggy2 + 4;
}
if (System.currentTimeMillis() - lastTurn4 >= 2000) {
// Change direction here
//jump = false;
lastTurn4 = System.currentTimeMillis();
missileOffSetY = 0;
}
if (System.currentTimeMillis() - lastTurn3 >= 1000) {
// Change direction here
jump = false;
lastTurn3 = System.currentTimeMillis();
xbuggy = 0;
}
//draw a background color
canvas.drawColor(Color.argb(255, 0, 0, 0));
// Draw the background parallax
drawBackground(0);
// Draw the rest of the game
paint.setTextSize(60);
paint.setColor(Color.argb(255, 255, 255, 255));
//canvas.drawText("MOONPATROL3000", 350, screenHeight / 100 * 5, paint);
int resID = context.getResources().getIdentifier("vehicle",
"drawable", context.getPackageName());
Alien alien1 = new AttackingAlien(context, "right_side_hdpi");
Alien alien2 = new AttackingAlien(context, "object2_hdpi");
Alien alien3 = new AttackingAlien(context, "object1_hdpi");
int alienResID = context.getResources().getIdentifier("right_side_hdpi",
"drawable", context.getPackageName());
int alienResID2 = context.getResources().getIdentifier("right_side_hdpi",
"drawable", context.getPackageName());
int alienResID3 = context.getResources().getIdentifier("right_side_hdpi",
"drawable", context.getPackageName());
// Load the bitmap using the id
Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), resID);
Bitmap alienbitmap = BitmapFactory.decodeResource(context.getResources(), alienResID);
Bitmap alienbitmap2 = BitmapFactory.decodeResource(context.getResources(), alienResID2);
Bitmap alienbitmap3 = BitmapFactory.decodeResource(context.getResources(), alienResID3);
//paint.setTextSize(220);
//for (int i1 = 0; i1 < numberOfAlienshots; i1++) {
if (missileOffSetY < 300) {
canvas.drawText("|", o + 10 + alienbitmap2.getWidth() / 2, l + screenHeight / 100 * 25 + 75 + missileOffSetY, paint);
missileOffSetY = missileOffSetY + 10;
}
for (int i1 = 0; i1 < numberOfshots; i1++) {
// if horizontal missile hits alien 0
if (java.lang.Math.abs(j - i[i1]) * 2 < (alien1.getWidth() + 60) && java.lang.Math.abs(k +150+ screenHeight / 100 * 45 - (float) (screenHeight * 0.61)) * 2 < (alien1.getHeight() + 60)) {
//y1[i2] = -random.nextInt(1000); // reset to new vertical position
//score += 1;
//onScoreListener.onScore(score);
Log.d("missile", "missile hit! ");
j=-200;
}
// if vertical missile hits alien 0
if (java.lang.Math.abs(j - 185) * 2 < (alienbitmap.getWidth() + 60) && java.lang.Math.abs(j + 150 + screenHeight / 100 * 45 - (screenHeight / 100 * 95 - i[i1] - xbuggy2)) * 2 < (alienbitmap.getHeight() + 60)) {
j=-200;
}
// if horizontal missile hits alien 1, right now this won't happen
if (java.lang.Math.abs(j - i[i1]) * 2 < (alienbitmap.getWidth() + 60) && java.lang.Math.abs(k +150+ screenHeight / 100 * 45 - (float) (screenHeight * 0.61)) * 2 < (alienbitmap.getHeight() + 60)) {
j=-200;
}
// if vertical missile hits alien 1
if (java.lang.Math.abs(o + 10 - 185) * 2 < (alienbitmap.getWidth() + 60) && java.lang.Math.abs(l + screenHeight / 100 * 25 - (screenHeight / 100 * 95 - i[i1] - xbuggy2)) * 2 < (alienbitmap.getHeight() + 60)) {
o=-200;
}
canvas.drawText("o", i[i1], (float) (screenHeight * 0.61), paint);
canvas.drawText("o", 185, screenHeight / 100 * 95 - i[i1] - xbuggy2, paint);
if (i1 == numberOfshots - 1 && i[i1] > screenWidth) {
if (numberOfshots > 0) numberOfshots--;
if (ind > 0) ind--;
}
}
if (System.currentTimeMillis() - lastTurn >= 2000) {
// Change direction here
down = !down;
lastTurn = System.currentTimeMillis();
}
if (System.currentTimeMillis() - lastTurn2 >= 7000) {
// Change direction here
down2 = !down2;
lastTurn2 = System.currentTimeMillis();
}
// canvas.drawBitmap(alien1.getAlienbitmap(), j, k +150+ screenHeight / 100 * 45, paint);
canvas.drawBitmap(alienbitmap2, o + 10, l + screenHeight / 100 * 25, paint);
//canvas.drawBitmap(alienbitmap3, j+20, k+screenHeight / 100 * 5, paint);
drawBackground(1);
canvas.drawBitmap(bitmap, 50, (float) (screenHeight * 0.5) - xbuggy, paint);
// Draw the foreground parallax
for (int n = 0; n < numberOfshots; n++)
i[n] = i[n] + 20;
j = j + 10;
o = o + 7;
if (!down)
k=k+2;
else
k=k-2;
if (!down2)
l++;
else
l--;
// Unlock and draw the scene
ourHolder.unlockCanvasAndPost(canvas);
}
}
// Clean up our thread if the game is stopped
public void pause() {
running = false;
try {
gameThread.join();
} catch (InterruptedException e) {
// Error
}
}
// Make a new thread and start it
// Execution moves to our run method
public void resume() {
running = true;
gameThread = new Thread(this);
gameThread.start();
}
private void drawBackground(int position) {
// Make a copy of the relevant background
Background bg = backgrounds.get(position);
// define what portion of images to capture and
// what coordinates of screen to draw them at
// For the regular bitmap
Rect fromRect1 = new Rect(0, 0, bg.width - bg.xClip, bg.height);
Rect toRect1 = new Rect(bg.xClip, bg.startY, bg.width, bg.endY);
// For the reversed background
Rect fromRect2 = new Rect(bg.width - bg.xClip, 0, bg.width, bg.height);
Rect toRect2 = new Rect(0, bg.startY, bg.xClip, bg.endY);
//draw the two background bitmaps
if (!bg.reversedFirst) {
canvas.drawBitmap(bg.bitmap, fromRect1, toRect1, paint);
canvas.drawBitmap(bg.bitmapReversed, fromRect2, toRect2, paint);
} else {
canvas.drawBitmap(bg.bitmap, fromRect2, toRect2, paint);
canvas.drawBitmap(bg.bitmapReversed, fromRect1, toRect1, paint);
}
}
// Because we call this from onTouchEvent, this code will be executed for both
// normal touch events and for when the system calls this using Accessibility
#Override
public boolean performClick() {
super.performClick();
launchMissile();
return true;
}
private void launchMissile() {
i[ind] = 350; // what does it do?
ind++;
xbuggy2 = 0;
shoot = true;
}
// event listener for when the user touches the screen
#Override
public boolean onTouchEvent(MotionEvent event) {
boolean gameOver = false;
//if (paused) {
// paused = false;
//}
int action = MotionEventCompat.getActionMasked(event);
int coordX = (int) event.getX();
int coordY = (int) event.getY();
Log.d("coordY", "coordY " + coordY);
if (coordX < 220 && xbuggy == 0 && action == MotionEvent.ACTION_MOVE) {
jump = true;
shoot = false;
lastTurn3 = System.currentTimeMillis();
return true; // do nothing
}
if (coordX > 219 && action == MotionEvent.ACTION_DOWN) {
numberOfshots++;
performClick();
return true;
}
return true;
}
}
Your biggest error seems to be allocating 4 bitmaps in the draw routine. Allocate those bitmaps in the onCreate and simply call the global bitmaps, that you initialized onCreate(). That will fix your problem. You can draw them in their locations.
private void draw() {
Alien alien1 = new AttackingAlien(context, "right_side_hdpi");
Alien alien2 = new AttackingAlien(context, "object2_hdpi");
Alien alien3 = new AttackingAlien(context, "object1_hdpi");
You allocated a bunch of memory objects invoking the context and expanding the drawable and a bunch of other work. You could have just used the same aliens from last tick.
int alienResID = context.getResources().getIdentifier("right_side_hdpi",
"drawable", context.getPackageName());
int alienResID2 = context.getResources().getIdentifier("right_side_hdpi",
"drawable", context.getPackageName());
int alienResID3 = context.getResources().getIdentifier("right_side_hdpi",
"drawable", context.getPackageName());
The aliens IDs didn't change from the previous tick.
// Load the bitmap using the id
Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), resID);
Bitmap alienbitmap = BitmapFactory.decodeResource(context.getResources(), alienResID);
Bitmap alienbitmap2 = BitmapFactory.decodeResource(context.getResources(), alienResID2);
Bitmap alienbitmap3 = BitmapFactory.decodeResource(context.getResources(), alienResID3);
These are the same bitmaps from last tick and bitmaps are giant and getting them from resources is slow, and you are doing this EVERY tick.
}
}
Most of the other stuff is going to shave off half a ms here and there, but this here is going to maybe get you up to the right FPS ballpark.
Don't worry though you have others.
Much of your problem is solved by making the routines faster. This is a good time to say, you're doing it wrong. The typical and correct way to do this is to have a loop ticks every 17ms or so. And for the rest of the time is paused. Some errors are glaring.
Your biggest error seems to be allocating 4 bitmaps in the draw routine.
But, the draw routine only draws. You draw the stuff that needs to happen on your canvas and that's it. You don't allocate anything you don't inflate anything, you take the numbers you have for where stuff is, and draw the stuff you already have loaded in the memory in that location.
You are ticking and doing the collision detection, in the draw routine, and allocating a bunch of objects for this when they have to be thrown in the woodchipper in a split second anyway.
You should not create any objects outside your initialization or in those special cases when a new alien exists. You shouldn't ever use a "new" anywhere in a draw routine. Ever.
You are using brute force for collision detection, eventually don't. Find a nice acceleration structure you like and use that. For 1 object it won't matter though.
Don't call some alien class, while it looks prettier, you want raw numbers of the bounding boxes of the aliens. You want then to keep them in some sort of structure that allows referencing them very quickly (You need the frame in less than 17ms). Calling a bunch of width commands isn't really that helpful, even if they changed size just change the number for the hitbox. These methods allow you some nice structures for the data like having a sorted array of hitboxes you can binary search into them and find whether the moved object hits the object in a log(n) time with log(n) updates to the structure, or some various methods for traversing an Axis Aligned Bound Box Tree. This is something you eventually will need but it might work without this so long as you're keeping it simple. Though, truthfully it's just your bitmaps there doing most of the slowing.
There's a lot of other basic issues like putting the bounding box inside the if statement rather than making two additional rectangles. But there's other issues like making rectangles at all! You call the draw with the actual location rather than some allocate a big ass couple objects to call a function with. Just call the function with the numbers.
You should have a routine that does the drawing for you based on the locations of the stuff. It should be able to draw everything it needs to draw in less then 17ms. If it can't you won't ever hit the 60fps you need to hit. So in that case draw less stuff and do a better job of it. Does that space background need to be a bitmap? Could you just draw a bunch of points for the sky, and adjust the graphics accordingly. Your draw routine never allocates anything. Period. If you need to allocate something it should have been during the init. Allocations are the bane of your existence.
Your touches update the position of the stuff. The AI/Physics tick also updates the positions of things and checks for collusion. The draw only draws the stuff based on the positions and stuff in memory.
Run the update location tick in its own thread. You only need to cope with the concurrency bits where you would be reading and writing the same data. It just needs to synchronize the changing data reading of the data for the draw, so toss those sections (position update in touch, position update in tick, and getting the position for the draw routine itself) in a synchronized block with the same object.
I want to do a "zoomable paint", I mean a paint that I can zoom/zoom out and pan/drag the canvas and then draw on it.
I have a problem that I can't solve: when I draw while the canvas is zoomed, I retrieve the X and Y coordinate and effectively drawing it on the canvas. But these coordinates are not correct because of the zoomed canvas.
I tried to correct these (multiply by (zoomHeigh/screenHeight)) but I can't find a way to retrieve where I must draw on the original/none-zoomed screen
This is my code :
public class PaintView extends View {
public static int BRUSH_SIZE = 20;
public static final int DEFAULT_COLOR = Color.BLACK;
public static final int DEFAULT_BG_COLOR = Color.WHITE;
private static final float TOUCH_TOLERANCE = 4;
private float mX, mY;
private SerializablePath mPath;
private Paint mPaint;
private ArrayList<FingerPath> paths = new ArrayList<>();
private ArrayList<FingerPath> tempPaths = new ArrayList<>();
private int currentColor;
private int backgroundColor = DEFAULT_BG_COLOR;
private int strokeWidth;
private boolean emboss;
private boolean blur;
private boolean eraser;
private MaskFilter mEmboss;
private MaskFilter mBlur;
private Bitmap mBitmap;
private Canvas mCanvas;
private Paint mBitmapPaint = new Paint(Paint.DITHER_FLAG);
public boolean zoomViewActivated = false;
//These two constants specify the minimum and maximum zoom
private static float MIN_ZOOM = 1f;
private static float MAX_ZOOM = 5f;
private float scaleFactor = 1.f;
private ScaleGestureDetector detector;
//These constants specify the mode that we're in
private static int NONE = 0;
private static int DRAG = 1;
private static int ZOOM = 2;
private int mode;
//These two variables keep track of the X and Y coordinate of the finger when it first
//touches the screen
private float startX = 0f;
private float startY = 0f;
//These two variables keep track of the amount we need to translate the canvas along the X
//and the Y coordinate
private float translateX = 0f;
private float translateY = 0f;
//These two variables keep track of the amount we translated the X and Y coordinates, the last time we
//panned.
private float previousTranslateX = 0f;
private float previousTranslateY = 0f;
int currentPositionX = 0;
int currentPositionY = 0;
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
#Override
public boolean onScale(ScaleGestureDetector detector) {
scaleFactor *= detector.getScaleFactor();
scaleFactor = Math.max(MIN_ZOOM, Math.min(scaleFactor, MAX_ZOOM));
return true;
}
}
public ArrayList<FingerPath> getDividedPaths(float i){
for(FingerPath p : this.paths){
Matrix scaleMatrix = new Matrix();
scaleMatrix.setScale(i, i);
p.path.transform(scaleMatrix);
}
return this.paths;
}
public ArrayList<FingerPath> getPaths() {
return paths;
}
public void dividePath(float i) {
for(FingerPath p : this.paths){
Matrix scaleMatrix = new Matrix();
scaleMatrix.setScale(i, i);
p.path.transform(scaleMatrix);
}
}
public void setPaths(ArrayList<FingerPath> paths){
this.paths = paths;
}
public void setStrokeWidth(int value){
strokeWidth = value;
}
public PaintView(Context context) {
this(context, null);
detector = new ScaleGestureDetector(getContext(), new ScaleListener());
}
public PaintView(Context context, AttributeSet attrs) {
super(context, attrs);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(DEFAULT_COLOR);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setXfermode(null);
mPaint.setAlpha(0xff);
mEmboss = new EmbossMaskFilter(new float[] {1, 1, 1}, 0.4f, 6, 3.5f);
mBlur = new BlurMaskFilter(5, BlurMaskFilter.Blur.NORMAL);
detector = new ScaleGestureDetector(getContext(), new ScaleListener());
}
public void init(DisplayMetrics metrics) {
int height = metrics.heightPixels;
int width = metrics.widthPixels;
mBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
currentColor = DEFAULT_COLOR;
strokeWidth = BRUSH_SIZE;
}
public void normal() {
emboss = false;
blur = false;
eraser = false;
}
public void emboss() {
emboss = true;
blur = false;
eraser = false;
}
public void blur() {
emboss = false;
blur = true;
eraser = false;
}
public void eraser() {
eraser = true;
}
public void cancel(){
if(paths.size() != 0){
tempPaths.add(paths.get(paths.size()-1));
paths.remove(paths.size()-1);
invalidate();
}
}
public void redo(){
if(tempPaths.size() != 0){
paths.add(tempPaths.get(tempPaths.size()-1));
tempPaths.remove(tempPaths.size()-1);
invalidate();
}
}
public void clear() {
backgroundColor = DEFAULT_BG_COLOR;
paths.clear();
normal();
invalidate();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.save();
//We're going to scale the X and Y coordinates by the same amount
canvas.scale(scaleFactor, scaleFactor);
//If translateX times -1 is lesser than zero, let's set it to zero. This takes care of the left bound
if((translateX * -1) < 0) {
translateX = 0;
}
//This is where we take care of the right bound. We compare translateX times -1 to (scaleFactor - 1) * displayWidth.
//If translateX is greater than that value, then we know that we've gone over the bound. So we set the value of
//translateX to (1 - scaleFactor) times the display width. Notice that the terms are interchanged; it's the same
//as doing -1 * (scaleFactor - 1) * displayWidth
else if((translateX * -1) > (scaleFactor - 1) * getWidth()) {
translateX = (1 - scaleFactor) * getWidth();
}
if(translateY * -1 < 0) {
translateY = 0;
}
//We do the exact same thing for the bottom bound, except in this case we use the height of the display
else if((translateY * -1) > (scaleFactor - 1) * getHeight()) {
translateY = (1 - scaleFactor) * getHeight();
}
//We need to divide by the scale factor here, otherwise we end up with excessive panning based on our zoom level
//because the translation amount also gets scaled according to how much we've zoomed into the canvas.
canvas.translate(translateX / scaleFactor, translateY / scaleFactor);
/* The rest of your canvas-drawing code */
mCanvas.drawColor(backgroundColor);
if(paths != null){
for (FingerPath fp : paths) {
mPaint.setColor(fp.color);
mPaint.setStrokeWidth(fp.strokeWidth);
mPaint.setMaskFilter(null);
if (fp.emboss)
mPaint.setMaskFilter(mEmboss);
else if (fp.blur)
mPaint.setMaskFilter(mBlur);
if(fp.eraser) {
mPaint.setColor(DEFAULT_BG_COLOR);
}
mCanvas.drawPath(fp.path, mPaint);
}
}
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.restore();
}
private void touchStart(float x, float y) {
mPath = new SerializablePath();
FingerPath fp = new FingerPath(currentColor, emboss, blur, eraser, strokeWidth, mPath);
paths.add(fp);
tempPaths = new ArrayList<>();
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touchMove(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
}
}
private void touchUp() {
mPath.lineTo(mX, mY);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if(zoomViewActivated){
boolean dragged = false;
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
mode = DRAG;
//We assign the current X and Y coordinate of the finger to startX and startY minus the previously translated
//amount for each coordinates This works even when we are translating the first time because the initial
//values for these two variables is zero.
startX = event.getX() - previousTranslateX;
startY = event.getY() - previousTranslateY;
break;
case MotionEvent.ACTION_MOVE:
translateX = event.getX() - startX;
translateY = event.getY() - startY;
//We cannot use startX and startY directly because we have adjusted their values using the previous translation values.
//This is why we need to add those values to startX and startY so that we can get the actual coordinates of the finger.
double distance = Math.sqrt(Math.pow(event.getX() - (startX + previousTranslateX), 2) +
Math.pow(event.getY() - (startY + previousTranslateY), 2)
);
if(distance > 0) {
dragged = true;
}
break;
case MotionEvent.ACTION_POINTER_DOWN:
mode = ZOOM;
break;
case MotionEvent.ACTION_UP:
mode = NONE;
dragged = false;
//All fingers went up, so let's save the value of translateX and translateY into previousTranslateX and
//previousTranslate
previousTranslateX = translateX;
previousTranslateY = translateY;
currentPositionX += previousTranslateX;
currentPositionY += previousTranslateY;
break;
case MotionEvent.ACTION_POINTER_UP:
mode = DRAG;
//This is not strictly necessary; we save the value of translateX and translateY into previousTranslateX
//and previousTranslateY when the second finger goes up
previousTranslateX = translateX;
previousTranslateY = translateY;
break;
}
detector.onTouchEvent(event);
//We redraw the canvas only in the following cases:
//
// o The mode is ZOOM
// OR
// o The mode is DRAG and the scale factor is not equal to 1 (meaning we have zoomed) and dragged is
// set to true (meaning the finger has actually moved)
if ((mode == DRAG && scaleFactor != 1f && dragged) || mode == ZOOM) {
invalidate();
}
}else{
float x = event.getX()*(getHeight()/scaleFactor)/getHeight()+currentPositionX;
float y = event.getY()*(getWidth()/scaleFactor)/getWidth()+currentPositionY;
switch(event.getAction()) {
case MotionEvent.ACTION_DOWN :
touchStart(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE :
touchMove(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP :
touchUp();
invalidate();
break;
}
}
return true;
}
}
I am creating a maze game in libGDX. The background texture is very similar to this one: http://www.wpclipart.com/recreation/games/maze/maze_square_medium.png
My moving character is on the maze, and I would like to do collision detection between the character and black walls by checking the colour of my maze texture, without creating rectangles and figuring out all the coordinates of the maze walls, if that is possible. I have researched a lot, but since I am quite new to libGDX and even java, I haven't really found anything that made a lot of sense to me for my case. If anyone has an answer for me on how I could do this or can refer me to a page that explains this well, it would be very greatly appreciated!
EDIT:
This is my code right now:
private static final int COLS = 4;
private static final int ROWS = 4;
Sprite sprChar, sprMaze;
SpriteBatch batch;
Texture Sprite;
TextureRegion[] frames;
TextureRegion CurrentFrame;
float fTime = 0f, fSpeed = 4;
Animation animation;
Texture txtMaze;
Pixmap pixmap;
int nX, nY, nPix, nR, nG, nB, nA;
Color color;
#Override
public void create() {
batch = new SpriteBatch();
Sprite = new Texture(Gdx.files.internal("snowwhite.png"));
sprChar = new Sprite(Sprite);
sprChar.setPosition(300, 200);
TextureRegion[][] tmp = TextureRegion.split(Sprite, Sprite.getWidth() / COLS, Sprite.getHeight(
frames = new TextureRegion[COLS * ROWS];
int index = 0;
for (int i = 0; i < ROWS; i++) {
for (int j = 0; j < COLS; j++) {
frames[index++] = tmp[i][j];
}
}
animation = new Animation(1f, frames);
sprChar.setPosition(10, 10);
pixmap = new Pixmap(Gdx.files.internal("Maze2.png"));
color = new Color();
}
#Override
public void render() {
if (fTime < 4) {
fTime += Gdx.graphics.getDeltaTime();
} else {
fTime = 0;
}
nX = Math.round(sprChar.getX());
nY = Math.round(sprChar.getY());
nPix = pixmap.getPixel(nX, nY);
Color.rgba8888ToColor(color, nPix);
nR = (int) (color.r * 255f);
nG = (int) (color.g * 255f);
nB = (int) (color.b * 255f);
nA = (int) (color.a * 255f);
if (nR == 0 && nG == 0 && nB == 0) {
System.out.println("is hit");
}
txtMaze = new Texture(pixmap);
sprMaze = new Sprite(txtMaze);
CurrentFrame = animation.getKeyFrame(0);
if (Gdx.input.isKeyPressed(Input.Keys.LEFT)) {
sprChar.setX(sprChar.getX() - fSpeed);
CurrentFrame = animation.getKeyFrame(4 + fTime);
}
if (Gdx.input.isKeyPressed(Input.Keys.RIGHT)) {
sprChar.setX(sprChar.getX() + fSpeed);
CurrentFrame = animation.getKeyFrame(8 + fTime);
}
if (Gdx.input.isKeyPressed(Input.Keys.UP)) {
sprChar.setY(sprChar.getY() + fSpeed);
CurrentFrame = animation.getKeyFrame(12 + fTime);
}
if (Gdx.input.isKeyPressed(Input.Keys.DOWN)) {
sprChar.setY(sprChar.getY() - fSpeed);
CurrentFrame = animation.getKeyFrame(0 + fTime);
}
batch.begin();
Gdx.gl.glClearColor(1, 1, 1, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.draw(sprMaze, sprMaze.getX(), sprMaze.getY(), sprMaze.getWidth() / 2,
sprMaze.getHeight() / 2, sprMaze.getWidth(),
sprMaze.getHeight(), sprMaze.getScaleX(),
sprMaze.getScaleY(), sprMaze.getRotation());
batch.draw(CurrentFrame, sprChar.getX(), sprChar.getY(), 20, 20);
batch.end();
}
public static void updatePosition(Sprite spr, float fX, float fY) {
spr.setPosition(fX, fY);
}
I just want it to output "is hit" if it passes a black wall, but I don't believe I am getting correct responses. Also, if I try to resize the maze sprite, it seems to me that it still checks for pixels on the maze at the original size.
P.S. Please excuse my bad code, I am VERY new. So any help would be very greatly appreciated, as I am on a time crunch!! Thank you
I just started working with LibGDX and can't figure out how to hide an image when it collides with an object. In my game some dots come from the top of the screen and meet the dot at the bottom. When they meet the dots should hide that isn't happening.
This is the main Game Class
public class GameScreen implements Screen,InputProcessor {
final AmazingDot game;
//setting the height and width variables
private int height;
private int width;
private static int touchCounter;
//setting the two dots variables
private Texture playerDotImage;
private Texture gameDotImage;
private Texture gameDotImage1;
private Rectangle playerDotRectangle;
private Map<Rectangle,Texture> gameDotMap;
//storing the time of last dot in nano seconds
private long lastDotTime;
public GameScreen(final AmazingDot gam){
this.game = gam;
Gdx.input.setInputProcessor(this);
//getting the height and width of the user's screen
height = Gdx.graphics.getHeight();
width = Gdx.graphics.getWidth();
touchCounter =0;
//loading the images in the variables
playerDotImage = new Texture(Gdx.files.internal("images/dot2.png"));
gameDotImage = new Texture(Gdx.files.internal("images/dot1.png"));
gameDotImage1 = new Texture(Gdx.files.internal("images/dot2.png"));
//placing the player dot in the middle of the screen
playerDotRectangle = new Rectangle();
playerDotRectangle.x = width/ 2 - 64 / 2;
playerDotRectangle.y = 20;
playerDotRectangle.width = 64;
playerDotRectangle.height = 64;
gameDotMap = new ConcurrentHashMap<Rectangle, Texture>();
populateDots();
}
private void populateDots(){
Rectangle dots = new Rectangle();
dots.x = randomLocation();
dots.y = height;
dots.width = 64;
dots.height = 64;
Random rand = new Random();
int n = rand.nextInt(2) + 1;
if(n==1){
gameDotMap.put(dots,gameDotImage1);
}
else{
gameDotMap.put(dots,gameDotImage);
}
lastDotTime = TimeUtils.nanoTime();
}
private int randomLocation(){
int[] locations = new int[3];
locations[0]=0;
locations[1]=width/2-64/2;
locations[2]=width-64;
Random generator = new Random();
int randomIndex = generator.nextInt(locations.length);
return locations[randomIndex];
}
#Override
public void render(float delta) {
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
game.batch.begin();
game.batch.draw(playerDotImage,playerDotRectangle.x,playerDotRectangle.y,playerDotRectangle.width,playerDotRectangle.height);
for(Map.Entry<Rectangle,Texture> dots : gameDotMap.entrySet()){
game.batch.draw(dots.getValue(),dots.getKey().x,dots.getKey().y);
}
game.batch.end();
// check if we need to create a new dot
if(TimeUtils.nanoTime() - lastDotTime > 1000000000) populateDots();
for(Rectangle dot : gameDotMap.keySet()){
int gameSpeed = 400;
int xSpeed = calXSpeed(gameSpeed);
dot.y = dot.y - gameSpeed * Gdx.graphics.getDeltaTime();
if(dot.x <width/2-64/2){
dot.x = dot.x + xSpeed*Gdx.graphics.getDeltaTime();
}
else if(dot.x>width/2-64/2){
dot.x = dot.x - xSpeed*Gdx.graphics.getDeltaTime();
}
if(dot.y + 64 < 0) gameDotMap.remove(dot);
if(dot.overlaps(playerDotRectangle)) {
//this is where I am trying to remove the map object on collision
gameDotMap.remove(dot);
}
}
}
private int calXSpeed(int gameSpeed){
int seconds = height/gameSpeed;
int distance = width/2-64/2;
int speed = distance/seconds;
return speed;
}
#Override
public boolean touchDown(int screenX, int screenY, int pointer, int button) {
touchCounter++;
if(touchCounter % 2==0){
playerDotImage = new Texture(Gdx.files.internal("images/dot2.png"));
}
else{
playerDotImage = new Texture(Gdx.files.internal("images/dot1.png"));
}
return true;
}
#Override
public void dispose() {
playerDotImage.dispose();
gameDotImage.dispose();
gameDotImage1.dispose();
}
}
EDIT
As you can see in the above image when the moving dot reaches the stationary dot, it should disappear. But here in my code the dot just moves past the stationary dot. I am using rectangles(LibGdx) to detect whether the dots overlap each other or not.
Define you Map as an ArrayMap like so:
private ArrayMap<Rectangle, Texture> gameDotMap;
Then you can rewrite you render method like this:
#Override
public void render(float delta) {
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
game.batch.begin();
game.batch.draw(playerDotImage, playerDotRectangle.x, playerDotRectangle.y, playerDotRectangle.width, playerDotRectangle.height);
for (int i = 0; i < gameDotMap.size; i++) {
game.batch.draw(gameDotMap.getValueAt(i), gameDotMap.getKeyAt(i).x, gameDotMap.getKeyAt(i).y);
}
game.batch.end();
// check if we need to create a new dot
if (TimeUtils.nanoTime() - lastDotTime > 1000000000) {
populateDots();
}
for (Iterator<ObjectMap.Entry<Rectangle, Texture>> iter = gameDotMap.iterator(); iter.hasNext();) {
ObjectMap.Entry<Rectangle, Texture> entry = iter.next();
Rectangle dot = entry.key;
int gameSpeed = 400;
int xSpeed = calXSpeed(gameSpeed);
dot.y = dot.y - gameSpeed * Gdx.graphics.getDeltaTime();
if (dot.x < width / 2 - 64 / 2) {
dot.x = dot.x + xSpeed * Gdx.graphics.getDeltaTime();
} else if (dot.x > width / 2 - 64 / 2) {
dot.x = dot.x - xSpeed * Gdx.graphics.getDeltaTime();
}
if (dot.y + 64 < 0) {
iter.remove();
}
if (dot.overlaps(playerDotRectangle)) {
//this is where I am trying to remove the map object on collision
iter.remove();
}
}
}
LibGDX has specific types for collections, they are recommended over the JDK's collections.
Here I have use 'HoloGraph' Library for Doughnut chart But Now I need to show with animation. Please suggest me How can I do it?
I have done without animation
Here's how i finally did it after two days of search with help of this library https://github.com/Ken-Yang/AndroidPieChart
And equations to center text done with help of my friends and alot of search
on MainActivity onCreate or oncreateView if you are using fragments:
PieChart pie = (PieChart) rootView.findViewById(R.id.pieChart);
ArrayList<Float> alPercentage = new ArrayList<Float>();
alPercentage.add(2.0f);
alPercentage.add(8.0f);
alPercentage.add(20.0f);
alPercentage.add(10.0f);
alPercentage.add(10.0f);
alPercentage.add(10.0f);
alPercentage.add(10.0f);
alPercentage.add(10.0f);
alPercentage.add(10.85f);
alPercentage.add(9.15f);
try {
// setting data
pie.setAdapter(alPercentage);
// setting a listener
pie.setOnSelectedListener(new OnSelectedLisenter() {
#Override
public void onSelected(int iSelectedIndex) {
Toast.makeText(getActivity(),
"Select index:" + iSelectedIndex,
Toast.LENGTH_SHORT).show();
}
});
} catch (Exception e) {
if (e.getMessage().equals(PieChart.ERROR_NOT_EQUAL_TO_100)) {
Log.e("kenyang", "percentage is not equal to 100");
}
}
public class PieChart extends View {
public interface OnSelectedLisenter {
public abstract void onSelected(int iSelectedIndex);
}
private OnSelectedLisenter onSelectedListener = null;
private static final String TAG = PieChart.class.getName();
public static final String ERROR_NOT_EQUAL_TO_100 = "NOT_EQUAL_TO_100";
private static final int DEGREE_360 = 360;
private static String[] PIE_COLORS = null;
private static int iColorListSize = 0;
ArrayList<Float> array;
private Paint paintPieFill;
private Paint paintPieBorder;
private Paint paintCenterCircle;
private ArrayList<Float> alPercentage = new ArrayList<Float>();
private int mCenterX = 320;
private int mCenterY = 320;
private int iDisplayWidth, iDisplayHeight;
private int iSelectedIndex = -1;
private int iCenterWidth = 0;
private int iShift = 0;
private int iMargin = 0; // margin to left and right, used for get Radius
private int iDataSize = 0;
private Canvas canvas1;
private RectF r = null;
private RectF centerCircle = null;
private float fDensity = 0.0f;
private float fStartAngle = 0.0f;
private float fEndAngle = 0.0f;
float fX;
float fY;
public PieChart(Context context, AttributeSet attrs) {
super(context, attrs);
PIE_COLORS = getResources().getStringArray(R.array.colors);
iColorListSize = PIE_COLORS.length;
array = new ArrayList<Float>();
fnGetDisplayMetrics(context);
iShift = (int) fnGetRealPxFromDp(30);
iMargin = (int) fnGetRealPxFromDp(40);
centerCircle = new RectF(200, 200, 440, 440);
// used for paint circle
paintPieFill = new Paint(Paint.ANTI_ALIAS_FLAG);
paintPieFill.setStyle(Paint.Style.FILL);
// used for paint centerCircle
paintCenterCircle = new Paint(Paint.ANTI_ALIAS_FLAG);
paintCenterCircle.setStyle(Paint.Style.FILL);
paintCenterCircle.setColor(Color.WHITE);
// used for paint border
paintPieBorder = new Paint(Paint.ANTI_ALIAS_FLAG);
paintPieBorder.setStyle(Paint.Style.STROKE);
paintPieBorder.setStrokeWidth(fnGetRealPxFromDp(3));
paintPieBorder.setColor(Color.WHITE);
Log.i(TAG, "PieChart init");
}
// set listener
public void setOnSelectedListener(OnSelectedLisenter listener) {
this.onSelectedListener = listener;
}
float temp = 0;
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Log.i(TAG, "onDraw");
float centerX = (r.left + r.right) / 2;
float centerY = (r.top + r.bottom) / 2;
float radius1 = (r.right - r.left) / 2;
radius1 *= 0.5;
float startX = mCenterX;
float startY = mCenterY;
float radius = mCenterX;
float medianAngle = 0;
Path path = new Path();
for (int i = 0; i < iDataSize; i++) {
// check whether the data size larger than color list size
if (i >= iColorListSize) {
paintPieFill.setColor(Color.parseColor(PIE_COLORS[i
% iColorListSize]));
} else {
paintPieFill.setColor(Color.parseColor(PIE_COLORS[i]));
}
fEndAngle = alPercentage.get(i);
// convert percentage to angle
fEndAngle = fEndAngle / 100 * DEGREE_360;
// if the part of pie was selected then change the coordinate
if (iSelectedIndex == i) {
canvas.save(Canvas.MATRIX_SAVE_FLAG);
float fAngle = fStartAngle + fEndAngle / 2;
double dxRadius = Math.toRadians((fAngle + DEGREE_360)
% DEGREE_360);
fY = (float) Math.sin(dxRadius);
fX = (float) Math.cos(dxRadius);
canvas.translate(fX * iShift, fY * iShift);
}
canvas.drawArc(r, fStartAngle, fEndAngle, true, paintPieFill);
float angle = (float) ((fStartAngle + fEndAngle / 2) * Math.PI / 180);
float stopX = (float) (startX + (radius/2) * Math.cos(angle));
float stopY = (float) (startY + (radius/2) * Math.sin(angle));
// if the part of pie was selected then draw a border
if (iSelectedIndex == i) {
canvas.drawArc(r, fStartAngle, fEndAngle, true, paintPieBorder);
canvas.drawLine(startX, startY, stopX, stopY, paintPieFill);
canvas.restore();
}
fStartAngle = fStartAngle + fEndAngle;
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
// get screen size
iDisplayWidth = MeasureSpec.getSize(widthMeasureSpec);
iDisplayHeight = MeasureSpec.getSize(heightMeasureSpec);
if (iDisplayWidth > iDisplayHeight) {
iDisplayWidth = iDisplayHeight;
}
/*
* determine the rectangle size
*/
iCenterWidth = iDisplayWidth / 2;
int iR = iCenterWidth - iMargin;
if (r == null) {
r = new RectF(iCenterWidth - iR, // top
iCenterWidth - iR, // left
iCenterWidth + iR, // right
iCenterWidth + iR); // bottom
}
if (centerCircle == null) {
// centerCircle=new RectF(left, top, right, bottom);
}
setMeasuredDimension(iDisplayWidth, iDisplayWidth);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
// get degree of the touch point
double dx = Math.atan2(event.getY() - iCenterWidth, event.getX()
- iCenterWidth);
float fDegree = (float) (dx / (2 * Math.PI) * DEGREE_360);
fDegree = (fDegree + DEGREE_360) % DEGREE_360;
// get the percent of the selected degree
float fSelectedPercent = fDegree * 100 / DEGREE_360;
// check which pie was selected
float fTotalPercent = 0;
for (int i = 0; i < iDataSize; i++) {
fTotalPercent += alPercentage.get(i);
if (fTotalPercent > fSelectedPercent) {
iSelectedIndex = i;
break;
}
}
if (onSelectedListener != null) {
onSelectedListener.onSelected(iSelectedIndex);
}
invalidate();
return super.onTouchEvent(event);
}
private void fnGetDisplayMetrics(Context cxt) {
final DisplayMetrics dm = cxt.getResources().getDisplayMetrics();
fDensity = dm.density;
}
private float fnGetRealPxFromDp(float fDp) {
return (fDensity != 1.0f) ? fDensity * fDp : fDp;
}
public void setAdapter(ArrayList<Float> alPercentage) throws Exception {
this.alPercentage = alPercentage;
iDataSize = alPercentage.size();
float fSum = 0;
for (int i = 0; i < iDataSize; i++) {
fSum += alPercentage.get(i);
}
if (fSum != 100) {
Log.e(TAG, ERROR_NOT_EQUAL_TO_100);
iDataSize = 0;
throw new Exception(ERROR_NOT_EQUAL_TO_100);
}
}
In Layout:
<com.example.piecharts.PieChart
android:id="#+id/pieChart"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</com.example.piecharts.PieChart>