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+--- Thread: EXC_BAD_ACCESS (/thread-7970.html)

EXC_BAD_ACCESS - Holyhoppsan - Aug 10, 2010 01:14 AM

Hi!

I'm trying to combine obj-c with c++ since i'm more used to c++. My code that inits opengl works fine and everything runs smoothly until i try to render an image. somehow i get an EXC_BAD_ACCESS. I know that this is caused by my code when it tries to use memory that has been released before. but after running my code in instruments, i still can't seem to find the cause. the code that causes the EXC_BAD_ACCESS is the following:

Code:
#include "Image.h"


CORE::Image::Image()
{

}

CORE::Image::Image(const Image& aImage)
{
    NSLog(@"COPY");
}

CORE::Image::~Image()
{
    NSLog(@"IMage Destroy");
}

void CORE::Image::InitImage(std::string aTextureFileName, float aTextureSizeX, float aTextureSizeY)
{
    myTextureSizeX = aTextureSizeX;
    myTextureSizeY = aTextureSizeY;
    
    glGenTextures(1, &myTexture);
    glBindTexture(GL_TEXTURE_2D, myTexture);
    
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    
    std::string firstPartOfFileName;
    std::string fileExtension;
    bool hasFoundDot = false;
    
    for(unsigned int i = 0; i < aTextureFileName.length(); i++)
    {
        if(!hasFoundDot)
        {
            if(aTextureFileName[i] == '.')
            {
                hasFoundDot = true;
            }
            else
            {
                firstPartOfFileName += aTextureFileName[i];
            }
        }
        else
        {
            fileExtension += aTextureFileName[i];    
        }
    }
    
//    NSString *firstPart = [NSString stringWithUTF8String: firstPartOfFileName.c_str()];
//    NSString *extension = [NSString stringWithUTF8String: fileExtension.c_str()];
        
    
    NSString *path = [[NSBundle mainBundle] pathForResource:@"Hej" ofType:@"pvrtc"];
    NSData *texData = [[NSData alloc] initWithContentsOfFile:path];
    
    
    glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG, aTextureSizeX, aTextureSizeY, 0, [texData length], [texData bytes]);
}

void CORE::Image::Render(float aX, float aY)
{
    NSLog(@"RENDERAR");
    const GLfloat texCoords[] = {
        0.0, 1.0,
        1.0, 1.0,
        0.0, 0.0,
        1.0, 0.0
    };
    
    const GLfloat squareVertices[] = {
        aX, aY,
        aX + myTextureSizeX,  aY,
        aX,  aY + myTextureSizeY,
        aX + myTextureSizeX,   aY + myTextureSizeY,
    };
    
    glPushMatrix();
    
    glBindTexture(GL_TEXTURE_2D, myTexture);
    glVertexPointer(2, GL_FLOAT, 0, squareVertices);
    glTexCoordPointer(2, GL_FLOAT, 0, texCoords);
    
    glEnableClientState(GL_VERTEX_ARRAY);
    glEnableClientState(GL_TEXTURE_COORD_ARRAY);
    
    // Enable Texture_2D
    glEnable(GL_TEXTURE_2D);
    glEnable(GL_BLEND);
    
    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);  
    
    // Now we are done drawing disable blending
    glDisable(GL_BLEND);
    
    // Disable as necessary
    glDisable(GL_TEXTURE_2D);
    
    glDisableClientState(GL_VERTEX_ARRAY);
    glDisableClientState(GL_TEXTURE_COORD_ARRAY);
    
    glPopMatrix();
    
}

void CORE::Image::RenderFrame(float aX, float aY, float aFrameStartX, float aFrameStartY, float aWidth, float aHeight)
{
    if((aFrameStartX + aWidth) > myTextureSizeX)
    {
        NSLog(@"TextureSizeX %d", myTextureSizeX);
        assert(0);
    }
    if((aFrameStartY + aHeight) > myTextureSizeY)
    {
        NSLog(@"TextureSizeY %d", myTextureSizeY);
        assert(0);
    }
    
    float texStartX = (aFrameStartX) / myTextureSizeX;
    float texEndX = (aFrameStartX +aWidth) / myTextureSizeX;
    
    float texStartY = (aFrameStartY) / myTextureSizeY;
    float texEndY = (aFrameStartY + aHeight) / myTextureSizeY;
    
    const GLfloat texCoords[] = {
        texStartX, texEndY,
        texEndX, texEndY,
        texStartX, texStartY,
        texEndX, texStartY
    };
    
    const GLfloat squareVertices[] = {
        aX, aY,
        aX + aWidth,  aY,
        aX,  aY + aHeight,
        aX + aWidth,   aY + aHeight,
    };
    
    glBindTexture(GL_TEXTURE_2D, myTexture);
    glVertexPointer(2, GL_FLOAT, 0, squareVertices);
    glTexCoordPointer(2, GL_FLOAT, 0, texCoords);
    
    glEnableClientState(GL_VERTEX_ARRAY);
    glEnableClientState(GL_TEXTURE_COORD_ARRAY);
    
    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);  
    
    glDisableClientState(GL_VERTEX_ARRAY);
    glDisableClientState(GL_TEXTURE_COORD_ARRAY);
    
}
If i run my app without trying to render an image everything works fine so the opengl es is properly initialized.

RE: EXC_BAD_ACCESS - SethWillits - Aug 10, 2010 11:27 AM

(Aug 10, 2010 01:14 AM)Holyhoppsan Wrote:  somehow i get an EXC_BAD_ACCESS. I know that this is caused by my code when it tries to use memory that has been released before.

Evidenced by....?


Quote:but after running my code in instruments, i still can't seem to find the cause.

If you run the code with the debugger attached it'll break on the line that caused the exception. If you're getting a standard crash log, it'll tell you the stack trace from when the crash occurred.

Those are your best sources to find the problem.




Btw:

Code:
    NSData *texData = [[NSData alloc] initWithContentsOfFile:path];
    glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG, aTextureSizeX, aTextureSizeY, 0, [texData length], [texData bytes]);

Leak.

RE: EXC_BAD_ACCESS - Holyhoppsan - Aug 10, 2010 01:44 PM

(Aug 10, 2010 11:27 AM)FreakSoftware Wrote:  
(Aug 10, 2010 01:14 AM)Holyhoppsan Wrote:  somehow i get an EXC_BAD_ACCESS. I know that this is caused by my code when it tries to use memory that has been released before.

Evidenced by....?


Quote:but after running my code in instruments, i still can't seem to find the cause.

If you run the code with the debugger attached it'll break on the line that caused the exception. If you're getting a standard crash log, it'll tell you the stack trace from when the crash occurred.

Those are your best sources to find the problem.




Btw:

Code:
    NSData *texData = [[NSData alloc] initWithContentsOfFile:path];
    glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG, aTextureSizeX, aTextureSizeY, 0, [texData length], [texData bytes]);

Leak.

Thanks for spoting the leak.

After a day of trial and error i've noticed that the cause of this problem is not in my imageclass. The app gives me a bad access error while calling the following code:
Code:
[EAGLContext setCurrentContext:myContext];
    
    glBindFramebufferOES(GL_FRAMEBUFFER_OES, myViewFramebuffer);
    glViewport(0, 0, 320, 480); <-- It crashes here

    glClear(GL_COLOR_BUFFER_BIT); // or sometimes here
    
    for(int taskIndex = 0; taskIndex < myRenderList.Count(); taskIndex++)
    {
        if(myRenderList[taskIndex].type == IMAGE)
        {
            myResourceHandler.GetSprite(myRenderList[taskIndex].key)->Render(myRenderList[taskIndex].x, myRenderList[taskIndex].y);
        }
        if(myRenderList[taskIndex].type == FRAME)
        {
            myResourceHandler.GetSprite(myRenderList[taskIndex].key)->RenderFrame(myRenderList[taskIndex].x, myRenderList[taskIndex].y, myRenderList[taskIndex].frameStartX, myRenderList[taskIndex].frameStartY, myRenderList[taskIndex].width, myRenderList[taskIndex].height);
        }
    }
    
    glBindRenderbufferOES(GL_RENDERBUFFER_OES, myViewFramebuffer);
    [myContext presentRenderbuffer:GL_RENDERBUFFER_OES];


    myRenderList.RemoveAll();