[android-developers] Re: Black Screen problem with graphics update using unlockCanvasAndPost()
Your package is package com.baltz.scorched;
Does that mean you're working on a scorched earth type game? It would
be really crazy if you were, because I just started work on the same
game, and I'm using the LunarLander game as a template as well.
It's also my first game - maybe we can help each other out!
-Rick
On Apr 15, 10:25 pm, Warren warrenba...@gmail.com wrote:
Sarnoth, I appreciate you taking the time to comment.
Does that matter - if the thread isn't different?
Just in case there were problems with the thread, I rewrote the
program not to use a second thread and just execute the drawing loop
in the view.
In the code sample, I also changed draw() to drawSprites(), as I
described in an earlier post. Neither of these things helped.
== Begin Code ==
package com.baltz.scorched;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
class ScorchedView extends SurfaceView implements
SurfaceHolder.Callback {
private Context context;
private SurfaceHolder holder;
private Bitmap backgroundImage;
private Bitmap foregroundImage;
private Bitmap spriteImage;
private Resources resources;
private ScorchedTerrain terrain;
private Engine engine;
public ScorchedView(Context c, AttributeSet attrs) {
super(c, attrs);
// register our interest in hearing about changes to our
surface
holder = getHolder();
holder.addCallback(this);
context = c;
resources = context.getResources();
// load background image as a Bitmap instead of a Dable b/c
// we don't need to transform it and it's faster to d this way
backgroundImage = BitmapFactory.decodeResource(resources,
R.drawable.earthrise);
foregroundImage = BitmapFactory.decodeResource(resources,
R.drawable.foreground1);
spriteImage = BitmapFactory.decodeResource(resources,
R.drawable.sprite1);
terrain = new ScorchedTerrain(foregroundImage);
engine = new Engine();
Body body;
body = new Body(spriteImage);
body.setLocation(50, 50);
engine.addBody(body);
body = new Body(spriteImage);
body.setLocation(40, 100);
engine.addBody(body);
}
/* Callback invoked when the surface dimensions change. */
public void surfaceChanged(SurfaceHolder h, int format, int width,
int height) {
holder = h;
}
/*
* Callback invoked when the Surface has been created and is ready
to be
* used.
*/
public void surfaceCreated(SurfaceHolder h) {
holder = h;
gameLoop();
}
/*
* Callback invoked when the Surface has been destroyed and must
no longer
* be touched. WARNING: after this method returns, the Surface/
Canvas must
* never be touched again!
*/
public void surfaceDestroyed(SurfaceHolder holder) {
}
private void gameLoop(){
Canvas canvas;
int i=0;
while(i30){
canvas = null;
try {
canvas = holder.lockCanvas(null);
engine.update();
drawSprites(canvas);
} finally {
// do this in a finally so that if an exception is thrown
// during the above, we don't leave the Surface in an
// inconsistent state
if (canvas != null) {
Log.w(dbg, unlocking canvas + i);
holder.unlockCanvasAndPost(canvas);
}
}
try{
Thread.currentThread().sleep(300);
}
catch(Exception e){
}
i++;
}
}
/**
* Draws the sprites and background to the provided
* Canvas.
*/
public void drawSprites(Canvas canvas) {
// Draw the background image. Operations on the Canvas
accumulate
// so this is like clearing the screen.
canvas.drawBitmap(backgroundImage, 0, 0, null);
//draw the up-to-date, deformed foreground
terrain.draw(canvas);
//draw all bodies (players, projectiles, etc) on the screen
engine.drawAll(canvas);
}
}
On Apr 15, 4:47 pm, Sarnoth jesse.st...@gmail.com wrote:
I can't really say without seeing more of the code, but based on your
description of the problem I wonder if your thread is in fact a
separate thread or if the run method is simply being executed in the
main UI thread. Something worth checking. You can log
[android-developers] Re: Black Screen problem with graphics update using unlockCanvasAndPost()
You definitely need to do your game loop on a different thread. If
your game loop is running in the main UI thread then while it is
running the screen can't update and you can't get input events. The UI
thread is what does these things.
On Apr 15, 10:25 pm, Warren warrenba...@gmail.com wrote:
Sarnoth, I appreciate you taking the time to comment.
Does that matter - if the thread isn't different?
Just in case there were problems with the thread, I rewrote the
program not to use a second thread and just execute the drawing loop
in the view.
In the code sample, I also changed draw() to drawSprites(), as I
described in an earlier post. Neither of these things helped.
== Begin Code ==
package com.baltz.scorched;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
class ScorchedView extends SurfaceView implements
SurfaceHolder.Callback {
private Context context;
private SurfaceHolder holder;
private Bitmap backgroundImage;
private Bitmap foregroundImage;
private Bitmap spriteImage;
private Resources resources;
private ScorchedTerrain terrain;
private Engine engine;
public ScorchedView(Context c, AttributeSet attrs) {
super(c, attrs);
// register our interest in hearing about changes to our
surface
holder = getHolder();
holder.addCallback(this);
context = c;
resources = context.getResources();
// load background image as a Bitmap instead of a Dable b/c
// we don't need to transform it and it's faster to d this way
backgroundImage = BitmapFactory.decodeResource(resources,
R.drawable.earthrise);
foregroundImage = BitmapFactory.decodeResource(resources,
R.drawable.foreground1);
spriteImage = BitmapFactory.decodeResource(resources,
R.drawable.sprite1);
terrain = new ScorchedTerrain(foregroundImage);
engine = new Engine();
Body body;
body = new Body(spriteImage);
body.setLocation(50, 50);
engine.addBody(body);
body = new Body(spriteImage);
body.setLocation(40, 100);
engine.addBody(body);
}
/* Callback invoked when the surface dimensions change. */
public void surfaceChanged(SurfaceHolder h, int format, int width,
int height) {
holder = h;
}
/*
* Callback invoked when the Surface has been created and is ready
to be
* used.
*/
public void surfaceCreated(SurfaceHolder h) {
holder = h;
gameLoop();
}
/*
* Callback invoked when the Surface has been destroyed and must
no longer
* be touched. WARNING: after this method returns, the Surface/
Canvas must
* never be touched again!
*/
public void surfaceDestroyed(SurfaceHolder holder) {
}
private void gameLoop(){
Canvas canvas;
int i=0;
while(i30){
canvas = null;
try {
canvas = holder.lockCanvas(null);
engine.update();
drawSprites(canvas);
} finally {
// do this in a finally so that if an exception is thrown
// during the above, we don't leave the Surface in an
// inconsistent state
if (canvas != null) {
Log.w(dbg, unlocking canvas + i);
holder.unlockCanvasAndPost(canvas);
}
}
try{
Thread.currentThread().sleep(300);
}
catch(Exception e){
}
i++;
}
}
/**
* Draws the sprites and background to the provided
* Canvas.
*/
public void drawSprites(Canvas canvas) {
// Draw the background image. Operations on the Canvas
accumulate
// so this is like clearing the screen.
canvas.drawBitmap(backgroundImage, 0, 0, null);
//draw the up-to-date, deformed foreground
terrain.draw(canvas);
//draw all bodies (players, projectiles, etc) on the screen
engine.drawAll(canvas);
}
}
On Apr 15, 4:47 pm, Sarnoth jesse.st...@gmail.com wrote:
I can't really say without seeing more of the code, but based on your
description of the problem I wonder if your thread is in fact a
separate thread or if the run method is simply being executed in the
main UI thread. Something worth checking. You can log
Thread.currentThread().getName() from inside your run method and from
[android-developers] Re: Black Screen problem with graphics update using unlockCanvasAndPost()
Sarnoth, that's great to know. I'll undo the changes I made (that I
thought would simply for testing it appears to have made the situation
worse) then test to see if the game loop is indeed running in its own
thread.
On Apr 16, 12:28 pm, Sarnoth jesse.st...@gmail.com wrote:
You definitely need to do your game loop on a different thread. If
your game loop is running in the main UI thread then while it is
running thescreencan't update and you can't get input events. The UI
thread is what does these things.
On Apr 15, 10:25 pm, Warren warrenba...@gmail.com wrote:
Sarnoth, I appreciate you taking the time to comment.
Does that matter - if the thread isn't different?
Just in case there were problems with the thread, I rewrote the
program not to use a second thread and just execute the drawing loop
in the view.
In the code sample, I also changed draw() to drawSprites(), as I
described in an earlier post. Neither of these things helped.
== Begin Code ==
package com.baltz.scorched;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
class ScorchedView extends SurfaceView implements
SurfaceHolder.Callback {
private Context context;
private SurfaceHolder holder;
private Bitmap backgroundImage;
private Bitmap foregroundImage;
private Bitmap spriteImage;
private Resources resources;
private ScorchedTerrain terrain;
private Engine engine;
public ScorchedView(Context c, AttributeSet attrs) {
super(c, attrs);
// register our interest in hearing about changes to our
surface
holder = getHolder();
holder.addCallback(this);
context = c;
resources = context.getResources();
// load background image as a Bitmap instead of a Dable b/c
// we don't need to transform it and it's faster to d this way
backgroundImage = BitmapFactory.decodeResource(resources,
R.drawable.earthrise);
foregroundImage = BitmapFactory.decodeResource(resources,
R.drawable.foreground1);
spriteImage = BitmapFactory.decodeResource(resources,
R.drawable.sprite1);
terrain = new ScorchedTerrain(foregroundImage);
engine = new Engine();
Body body;
body = new Body(spriteImage);
body.setLocation(50, 50);
engine.addBody(body);
body = new Body(spriteImage);
body.setLocation(40, 100);
engine.addBody(body);
}
/* Callback invoked when the surface dimensions change. */
public void surfaceChanged(SurfaceHolder h, int format, int width,
int height) {
holder = h;
}
/*
* Callback invoked when the Surface has been created and is ready
to be
* used.
*/
public void surfaceCreated(SurfaceHolder h) {
holder = h;
gameLoop();
}
/*
* Callback invoked when the Surface has been destroyed and must
no longer
* be touched. WARNING: after this method returns, the Surface/
Canvas must
* never be touched again!
*/
public void surfaceDestroyed(SurfaceHolder holder) {
}
private void gameLoop(){
Canvas canvas;
int i=0;
while(i30){
canvas = null;
try {
canvas = holder.lockCanvas(null);
engine.update();
drawSprites(canvas);
} finally {
// do this in a finally so that if an exception is
thrown
// during the above, we don't leave the Surface in an
// inconsistent state
if (canvas != null) {
Log.w(dbg, unlocking canvas + i);
holder.unlockCanvasAndPost(canvas);
}
}
try{
Thread.currentThread().sleep(300);
}
catch(Exception e){
}
i++;
}
}
/**
* Draws the sprites and background to the provided
* Canvas.
*/
public void drawSprites(Canvas canvas) {
// Draw the background image. Operations on the Canvas
accumulate
// so this is like clearing thescreen.
canvas.drawBitmap(backgroundImage, 0, 0, null);
//draw the up-to-date, deformed foreground
terrain.draw(canvas);
//draw all bodies (players, projectiles, etc) on thescreen
engine.drawAll(canvas);
}
}
[android-developers] Re: Black Screen problem with graphics update using unlockCanvasAndPost()
Does that mean you're working on a scorched earth type game?
Maybe. :)
On Apr 16, 8:53 am, john jbatk...@gmail.com wrote:
Your package is package com.baltz.scorched;
Does that mean you're working on a scorched earth type game? It would
be really crazy if you were, because I just started work on the same
game, and I'm using the LunarLander game as a template as well.
It's also my first game - maybe we can help each other out!
-Rick
On Apr 15, 10:25 pm, Warren warrenba...@gmail.com wrote:
Sarnoth, I appreciate you taking the time to comment.
Does that matter - if the thread isn't different?
Just in case there were problems with the thread, I rewrote the
program not to use a second thread and just execute the drawing loop
in the view.
In the code sample, I also changed draw() to drawSprites(), as I
described in an earlier post. Neither of these things helped.
== Begin Code ==
package com.baltz.scorched;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
class ScorchedView extends SurfaceView implements
SurfaceHolder.Callback {
private Context context;
private SurfaceHolder holder;
private Bitmap backgroundImage;
private Bitmap foregroundImage;
private Bitmap spriteImage;
private Resources resources;
private ScorchedTerrain terrain;
private Engine engine;
public ScorchedView(Context c, AttributeSet attrs) {
super(c, attrs);
// register our interest in hearing about changes to our
surface
holder = getHolder();
holder.addCallback(this);
context = c;
resources = context.getResources();
// load background image as a Bitmap instead of a Dable b/c
// we don't need to transform it and it's faster to d this way
backgroundImage = BitmapFactory.decodeResource(resources,
R.drawable.earthrise);
foregroundImage = BitmapFactory.decodeResource(resources,
R.drawable.foreground1);
spriteImage = BitmapFactory.decodeResource(resources,
R.drawable.sprite1);
terrain = new ScorchedTerrain(foregroundImage);
engine = new Engine();
Body body;
body = new Body(spriteImage);
body.setLocation(50, 50);
engine.addBody(body);
body = new Body(spriteImage);
body.setLocation(40, 100);
engine.addBody(body);
}
/* Callback invoked when the surface dimensions change. */
public void surfaceChanged(SurfaceHolder h, int format, int width,
int height) {
holder = h;
}
/*
* Callback invoked when the Surface has been created and is ready
to be
* used.
*/
public void surfaceCreated(SurfaceHolder h) {
holder = h;
gameLoop();
}
/*
* Callback invoked when the Surface has been destroyed and must
no longer
* be touched. WARNING: after this method returns, the Surface/
Canvas must
* never be touched again!
*/
public void surfaceDestroyed(SurfaceHolder holder) {
}
private void gameLoop(){
Canvas canvas;
int i=0;
while(i30){
canvas = null;
try {
canvas = holder.lockCanvas(null);
engine.update();
drawSprites(canvas);
} finally {
// do this in a finally so that if an exception is
thrown
// during the above, we don't leave the Surface in an
// inconsistent state
if (canvas != null) {
Log.w(dbg, unlocking canvas + i);
holder.unlockCanvasAndPost(canvas);
}
}
try{
Thread.currentThread().sleep(300);
}
catch(Exception e){
}
i++;
}
}
/**
* Draws the sprites and background to the provided
* Canvas.
*/
public void drawSprites(Canvas canvas) {
// Draw the background image. Operations on the Canvas
accumulate
// so this is like clearing thescreen.
canvas.drawBitmap(backgroundImage, 0, 0, null);
//draw the up-to-date, deformed foreground
terrain.draw(canvas);
//draw all bodies (players, projectiles, etc) on thescreen
engine.drawAll(canvas);
}
}
On Apr 15, 4:47 pm, Sarnoth jesse.st...@gmail.com wrote:
I
[android-developers] Re: Black Screen problem with graphics update using unlockCanvasAndPost()
The problem is your line Thread.currentThread().sleep(1000);//sleep for 1000 ms I believe with SurfaceView you have to draw your whole view on every screen refresh. You just need to loop as fast as possible and the system will throttle the speed in the calls to lockCanvas(). By sleeping for 1 second you are failing to provide a canvas for every refresh so the screen appears blank. What I don't know is whether there is any guidance on how quickly you have to get through your loop, i.e. what the maximum refresh rate is --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -~--~~~~--~~--~--~---
[android-developers] Re: Black Screen problem with graphics update using unlockCanvasAndPost()
Thanks for the comment ellipsoidmobile. If I remove the sleep, I still don't see anything until the very end. I don't need that sleep in there for the application. I only put it in so that, hopefully, I could see what was happening a little better. Also, I thought that the SurfaceView allowed you to write to the screen at your own pace, whatever that may be. So in this case, there would be nothing from the outside that's causing a screen refresh. The screen should stay how I left it until I post a new canvas. Am I misunderstanding this? What really confuses me is why the last call to unlockCanvasAndPost() does work. It seems like if an error prevented the first calls from functioning, then it would also prevent the last. On Apr 15, 3:09 am, ellipsoidmob...@googlemail.com ellipsoidmob...@googlemail.com wrote: The problem is your line Thread.currentThread().sleep(1000);//sleep for 1000 ms I believe with SurfaceView you have to draw your whole view on everyscreenrefresh. You just need to loop as fast as possible and the system will throttle the speed in the calls to lockCanvas(). By sleeping for 1 second you are failing to provide a canvas for every refresh so thescreenappears blank. What I don't know is whether there is any guidance on how quickly you have to get through your loop, i.e. what the maximum refresh rate is --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -~--~~~~--~~--~--~---
[android-developers] Re: Black Screen problem with graphics update using unlockCanvasAndPost()
I may have found my problem. The SurfaceView class implements a function called draw(Canvas). I unwittingly created my own function draw() with the same signature, overriding the original. I'm guessing that the SurfaceView probably calls draw() during unlockCanvasAndPost(). But instead of executing its original draw() method and doing what it is supposed to do, it calls my function - simply overwriting the canvas buffer without affecting the Surface at all... thus the black screen. I'm still confused about why it eventually shows. Perhaps some final cleanup code... I will test this tonight when I have access to my development computer and post my findings. On Apr 15, 8:48 am, Warren warrenba...@gmail.com wrote: Thanks for the comment ellipsoidmobile. If I remove the sleep, I still don't see anything until the very end. I don't need that sleep in there for the application. I only put it in so that, hopefully, I could see what was happening a little better. Also, I thought that the SurfaceView allowed you to write to the screen at your own pace, whatever that may be. So in this case, there would be nothing from the outside that's causing a screen refresh. The screen should stay how I left it until I post a new canvas. Am I misunderstanding this? What really confuses me is why the last call to unlockCanvasAndPost() does work. It seems like if an error prevented the first calls from functioning, then it would also prevent the last. On Apr 15, 3:09 am, ellipsoidmob...@googlemail.com ellipsoidmob...@googlemail.com wrote: The problem is your line Thread.currentThread().sleep(1000);//sleep for 1000 ms I believe with SurfaceView you have to draw your whole view on everyscreenrefresh. You just need to loop as fast as possible and the system will throttle the speed in the calls to lockCanvas(). By sleeping for 1 second you are failing to provide a canvas for every refresh so thescreenappears blank. What I don't know is whether there is any guidance on how quickly you have to get through your loop, i.e. what the maximum refresh rate is --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -~--~~~~--~~--~--~---
[android-developers] Re: Black Screen problem with graphics update using unlockCanvasAndPost()
I can't really say without seeing more of the code, but based on your description of the problem I wonder if your thread is in fact a separate thread or if the run method is simply being executed in the main UI thread. Something worth checking. You can log Thread.currentThread().getName() from inside your run method and from inside your activity's onCreate method to make sure they are different. On Apr 15, 9:57 am, Warren warrenba...@gmail.com wrote: I may have found my problem. The SurfaceView class implements a function called draw(Canvas). I unwittingly created my own function draw() with the same signature, overriding the original. I'm guessing that the SurfaceView probably calls draw() during unlockCanvasAndPost(). But instead of executing its original draw() method and doing what it is supposed to do, it calls my function - simply overwriting the canvas buffer without affecting the Surface at all... thus the black screen. I'm still confused about why it eventually shows. Perhaps some final cleanup code... I will test this tonight when I have access to my development computer and post my findings. On Apr 15, 8:48 am, Warren warrenba...@gmail.com wrote: Thanks for the comment ellipsoidmobile. If I remove the sleep, I still don't see anything until the very end. I don't need that sleep in there for the application. I only put it in so that, hopefully, I could see what was happening a little better. Also, I thought that the SurfaceView allowed you to write to the screen at your own pace, whatever that may be. So in this case, there would be nothing from the outside that's causing a screen refresh. The screen should stay how I left it until I post a new canvas. Am I misunderstanding this? What really confuses me is why the last call to unlockCanvasAndPost() does work. It seems like if an error prevented the first calls from functioning, then it would also prevent the last. On Apr 15, 3:09 am, ellipsoidmob...@googlemail.com ellipsoidmob...@googlemail.com wrote: The problem is your line Thread.currentThread().sleep(1000);//sleep for 1000 ms I believe with SurfaceView you have to draw your whole view on everyscreenrefresh. You just need to loop as fast as possible and the system will throttle the speed in the calls to lockCanvas(). By sleeping for 1 second you are failing to provide a canvas for every refresh so thescreenappears blank. What I don't know is whether there is any guidance on how quickly you have to get through your loop, i.e. what the maximum refresh rate is --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Android Developers group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -~--~~~~--~~--~--~---
[android-developers] Re: Black Screen problem with graphics update using unlockCanvasAndPost()
Sarnoth, I appreciate you taking the time to comment.
Does that matter - if the thread isn't different?
Just in case there were problems with the thread, I rewrote the
program not to use a second thread and just execute the drawing loop
in the view.
In the code sample, I also changed draw() to drawSprites(), as I
described in an earlier post. Neither of these things helped.
== Begin Code ==
package com.baltz.scorched;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
class ScorchedView extends SurfaceView implements
SurfaceHolder.Callback {
private Context context;
private SurfaceHolder holder;
private Bitmap backgroundImage;
private Bitmap foregroundImage;
private Bitmap spriteImage;
private Resources resources;
private ScorchedTerrain terrain;
private Engine engine;
public ScorchedView(Context c, AttributeSet attrs) {
super(c, attrs);
// register our interest in hearing about changes to our
surface
holder = getHolder();
holder.addCallback(this);
context = c;
resources = context.getResources();
// load background image as a Bitmap instead of a Dable b/c
// we don't need to transform it and it's faster to d this way
backgroundImage = BitmapFactory.decodeResource(resources,
R.drawable.earthrise);
foregroundImage = BitmapFactory.decodeResource(resources,
R.drawable.foreground1);
spriteImage = BitmapFactory.decodeResource(resources,
R.drawable.sprite1);
terrain = new ScorchedTerrain(foregroundImage);
engine = new Engine();
Body body;
body = new Body(spriteImage);
body.setLocation(50, 50);
engine.addBody(body);
body = new Body(spriteImage);
body.setLocation(40, 100);
engine.addBody(body);
}
/* Callback invoked when the surface dimensions change. */
public void surfaceChanged(SurfaceHolder h, int format, int width,
int height) {
holder = h;
}
/*
* Callback invoked when the Surface has been created and is ready
to be
* used.
*/
public void surfaceCreated(SurfaceHolder h) {
holder = h;
gameLoop();
}
/*
* Callback invoked when the Surface has been destroyed and must
no longer
* be touched. WARNING: after this method returns, the Surface/
Canvas must
* never be touched again!
*/
public void surfaceDestroyed(SurfaceHolder holder) {
}
private void gameLoop(){
Canvas canvas;
int i=0;
while(i30){
canvas = null;
try {
canvas = holder.lockCanvas(null);
engine.update();
drawSprites(canvas);
} finally {
// do this in a finally so that if an exception is thrown
// during the above, we don't leave the Surface in an
// inconsistent state
if (canvas != null) {
Log.w(dbg, unlocking canvas + i);
holder.unlockCanvasAndPost(canvas);
}
}
try{
Thread.currentThread().sleep(300);
}
catch(Exception e){
}
i++;
}
}
/**
* Draws the sprites and background to the provided
* Canvas.
*/
public void drawSprites(Canvas canvas) {
// Draw the background image. Operations on the Canvas
accumulate
// so this is like clearing the screen.
canvas.drawBitmap(backgroundImage, 0, 0, null);
//draw the up-to-date, deformed foreground
terrain.draw(canvas);
//draw all bodies (players, projectiles, etc) on the screen
engine.drawAll(canvas);
}
}
On Apr 15, 4:47 pm, Sarnoth jesse.st...@gmail.com wrote:
I can't really say without seeing more of the code, but based on your
description of the problem I wonder if your thread is in fact a
separate thread or if the run method is simply being executed in the
main UI thread. Something worth checking. You can log
Thread.currentThread().getName() from inside your run method and from
inside your activity's onCreate method to make sure they are
different.
On Apr 15, 9:57 am, Warren warrenba...@gmail.com wrote:
I may have found my problem.
The SurfaceView class implements a function called draw(Canvas).
I unwittingly created my own function draw() with the same signature,
overriding the original. I'm guessing that the SurfaceView probably
calls draw()
