Frame rate problem « cocos2d for iPhone

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Frame rate problem

(12 posts) (4 voices)

Started 7 months ago by ClintWall
Latest reply from ClintWall

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ClintWall
Member
Hey all,

In my app the user draws needs to draw a line. But When he does it causes a serious drop in frame rate. The line is drawn by putting the user's touches into an array and then using this loop.
```
for(int i = 0; i < [touchArray count]; i+=2)
	{
		glColor4ub(255,0,0,255);
		CGPoint start = [touchArray objectAtIndex:i];
		CGPoint end = [touchArray objectAtIndex:i+1];
		ccDrawLine(start, end);
		[player1 setDestination:end];
	}
```
This code draws the line fine but if the line is long then the frame rate drops. I am also need to run this code for 5 different lines. Is there a better way of drawing the line or is there a way to keep the frame rate up?

Thanks
Clinton
Posted 7 months ago #
ClintWall
Member

Also it works fine on the simulator. The frame dips on the device only.

Posted 7 months ago #
araker
Moderator

How many lines are you drawing before you see a frame dip. If it's just a couple then the problem must be something else. Perhaps you're using a lot of log statements in your code, which tends to be fine on the simulator, but hogs down the device.

Another thing, did you use a release build on the device and which cocos version are you using?

Posted 7 months ago #

cocos
Member

@ClintWall drawing a line (even quite a few of them) is not a problem
Run your code without the lines and see for yourself the frame drop:

for(int i = 0; i < [touchArray count]; i+=2)
	{
		//glColor4ub(255,0,0,255);
		CGPoint start = [touchArray objectAtIndex:i];
		CGPoint end = [touchArray objectAtIndex:i+1];
		//ccDrawLine(start, end);
		[player1 setDestination:end];
	}

Posted 7 months ago #

ClintWall
Member

I took out the drawline statements and the frame rate still dropped. I am drawing a lot of lines because the line is not straight. It can curve so I draw many lines to get a smooth curve. In one complete line I have about 150 objects in the touchArray. So that's about 150 ccDrawLines call in one complete line. And 5 complete lines can be drawn at once.
I am not using a lot of NSLogs, under 10. And the version of cocos is 0.99.1

Posted 7 months ago #

greamer
Member

150 is a lot of drawlines XD
I will try two things
1. put those CGPoints in a C array
and loop through that c array , do not use NSMutableArray, if this is still not good enough
2.
build your own vertices array and create your own ccDrawLineS function base off ccDrawLine, so you finish all line drawing with one function call

void ccDrawLines(ccVertex2F* vertices, int count)
{
        /*
	ccVertex2F vertices[2] = {
		{origin.x * CC_CONTENT_SCALE_FACTOR(), origin.y * CC_CONTENT_SCALE_FACTOR() },
		{destination.x * CC_CONTENT_SCALE_FACTOR(), destination.y * CC_CONTENT_SCALE_FACTOR() }
	};*/

	// Default GL states: GL_TEXTURE_2D, GL_VERTEX_ARRAY, GL_COLOR_ARRAY, GL_TEXTURE_COORD_ARRAY
	// Needed states: GL_VERTEX_ARRAY,
	// Unneeded states: GL_TEXTURE_2D, GL_TEXTURE_COORD_ARRAY, GL_COLOR_ARRAY
	glDisable(GL_TEXTURE_2D);
	glDisableClientState(GL_TEXTURE_COORD_ARRAY);
	glDisableClientState(GL_COLOR_ARRAY);

	glVertexPointer(2, GL_FLOAT, 0, vertices);
	glDrawArrays(GL_LINES, 0, count);

	// restore default state
	glEnableClientState(GL_COLOR_ARRAY);
	glEnableClientState(GL_TEXTURE_COORD_ARRAY);
	glEnable(GL_TEXTURE_2D);
}

Posted 7 months ago #

cocos
Member
@greamer and araker gave you good advice.
As I expected and you have confirmed - drawing a line itself is not a problem.
The problem is somewhere else. Even though the access to NSMutableArray is slow I am surprised that
150*5 accesses to the touchArray results in the frame drop. If this is really the case than replace NSMutableArray with faster container: C-Array , CCArray or STL Vector.

I also suggest to strategically put sparse CCLog statements to measure the performance. Be careful the CCLogs can easily kill the frame rate.
Better yet store intermediate time results in the object and print the result when needed.

It is very likely that your process of storing the data alone puts a heavy load on the CPU.

0.99.1 is quite old now. Consider upgrading. Also to get better results run program in the release mode without any log statements.

BTW:
```
typedef struct _ccVertex2F
{
   GLfloat x;
   GLfloat y;
} ccVertex2F;

struct CGPoint {
   CGFloat x;
   CGFloat y;
};
typedef struct CGPoint CGPoint;
```
Posted 7 months ago #

ClintWall
Member

So my new loop looks like

for(int i = 0; i < [[player1 touchArray] count]; i+=2)
		{
			CGPoint start = [player1 cycleTouchArray:i];
			CGPoint end = [player1 cycleTouchArray:i+1];
			[player1 setDestination:end];
			ccVertex2F touchVertex[2] = {
				{start.x * CC_CONTENT_SCALE_FACTOR(), start.y * CC_CONTENT_SCALE_FACTOR() },
				{end.x * CC_CONTENT_SCALE_FACTOR(), end.y * CC_CONTENT_SCALE_FACTOR() }
			};
		}

I am getting the warning Implicit declaration of function 'CC_CONTENT_SCALE_FACTOR' on the line
{start.x * CC_CONTENT_SCALE_FACTOR(), start.y * CC_CONTENT_SCALE_FACTOR() },
And the error

"CC_CONTENT_SCALE_FACTOR", referenced from:
-[level1 makePath:lastTouch:] in level1.o
-[level1 makePath:lastTouch:] in level1.o
-[level1 makePath:lastTouch:] in level1.o
-[level1 makePath:lastTouch:] in level1.o
Symbol(s) not found
Collect2: Id returned 1 exits status

Posted 7 months ago #

cocos
Member

@ClintWall Why do you optimize from the end? Take care of the container first.
BTW.
Include "ccMacros.h" in your 'level1.m' file.

Posted 7 months ago #
greamer
Member

@cocos totally agree XD

do your container first :P
if you need help on how to build a correct vertice array from an array of CGPoints to draw lines, let us know :)
BTW.. there should be no loop if you just call the ccDrawLines that i posted there... it takes an array of points and the size of that array

Posted 7 months ago #

ClintWall
Member

Hey sorry for this late response. I have been really busy with school. So I changed my code to this

NSMutableArray *array = [NSMutableArray array];
		for(int i = 0; i < [[player1 touchArray] count]; i++)
		{
			CGPoint start = [player1 cycleTouchArray:i];
		//	CGPoint end = [player1 cycleTouchArray:i+1];
		//	[player1 setDestination:end];
			[array addObject:[NSValue valueWithCGPoint:start]];
		}
		ccVertex2F touchVertex[2] = {
			{[[array objectAtIndex:0] CGPointValue].x * CC_CONTENT_SCALE_FACTOR(),
				[[array objectAtIndex:0] CGPointValue].y * CC_CONTENT_SCALE_FACTOR() },
			{[[array objectAtIndex:[array count] - 1] CGPointValue].x * CC_CONTENT_SCALE_FACTOR(),
				[[array objectAtIndex:[array count] - 1] CGPointValue].y * CC_CONTENT_SCALE_FACTOR() }
		};

And I am still getting the same errors as before. I tried #include and #import of ccMacros.h. I am using an NSMutableArray because I do not know how to use a C array. Also how would I call the ccDrawLines method?

Frame rate problem

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