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OpenGL IOS texture display problem

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I'm working on a simple little game for the iPhone, and I'd like to use textures, however I can't quite seem to get it working...

After some research I found this page and this site. Both are great references, and taught me a little bit about textures, however, after loading a texture using either function I can't get the texture displayed, here's what my code looks like:

Very Simple Texture Display Function (not working)

void drawTexture(GLuint texture, float x, float y, float w, float h){

glBindTexture(GL_TEXTURE_2D,texture);

GLfloat box[] = {x,y+h, x+w,y+h, x,y, x+w,y};
GLfloat tex[] = {0,0, 1,0, 1,1, 0,1};

glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);

glVertexPointer(2, GL_FLOAT, 0,box);
glTexCoordPointer(2, GL_FLOAT, 0, tex);

glDrawArrays(GL_TRIANGLE_STRIP,0,4);

glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
}


Normally, I'd not create an array every single frame only to display an image, but this is just an example. When I run this function, I get nothing. Blank- no image, nothing (unless of course I'd previously enabled a color array and hadn't disabled it afterwards)

Second Simple Display Function (this one uses a quick little class)

void draw_rect(RectObject* robj){
glVertexPointer(2, GL_FLOAT, 0, [robj vertices]);
glEnableClientState(GL_VERTEX_ARRAY);
glColorPointer(4, GL_UNSIGNED_BYTE, 0, [robj colors]);
glEnableClientState(GL_COLOR_ARRAY);

if ([robj texture] != -1){
glEnable(GL_TEXTURE_COORD_ARRAY);
glEnable(GL_TEXTURE_2D);
glClientActiveTexture([robj texture]);

glTexCoordPointer(2, GL_FLOAT, 0, defaultTexCoord);
glBindTexture(GL_TEXTURE_2D, [robj texture]);
}

glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

glDisable(GL_TEXTURE_2D);
glDisable(GL_TEXTURE_COORD_ARRAY);
}


This function on the other hand, does change the display, instead of outputting the texture however it outputs a black square...


Setup Background

In my init function I'm calling

glEnable(GL_TEXTURE_2D);
glEnable(GL_BLEND);
glBlendFunc(GL_ONE, GL_SRC_COLOR);


Two LONG Texture Loading Functions

struct Texture2D LoadImage(NSString* path)
{
struct Texture2D tex;
tex.texture = -1;

// Id for texture
GLuint texture;
// Generate textures
glGenTextures(1, &texture);
// Bind it
glBindTexture(GL_TEXTURE_2D, texture);
// Set a few parameters to handle drawing the image
//at lower and higher sizes than original
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE);

//NSString *path = [[NSString alloc] initWithUTF8String:imagefile.c_str()];
path = [[NSBundle mainBundle] pathForResource:path ofType:@""];
NSData *texData = [[NSData alloc] initWithContentsOfFile:path];
UIImage *image = [[UIImage alloc] initWithData:texData];
if (image == nil)
return tex;
// Get Image size
GLuint width = CGImageGetWidth(image.CGImage);
GLuint height = CGImageGetHeight(image.CGImage);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
// Allocate memory for image
void *imageData = malloc( height * width * 4 );
CGContextRef imgcontext = CGBitmapContextCreate(
imageData, width, height, 8, 4 * width, colorSpace,
kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big );
CGColorSpaceRelease( colorSpace );
CGContextClearRect( imgcontext,
CGRectMake( 0, 0, width, height ) );
CGContextTranslateCTM( imgcontext, 0, height - height );
CGContextDrawImage( imgcontext,
CGRectMake( 0, 0, width, height ), image.CGImage );

// Generate texture in opengl
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height,
0, GL_RGBA, GL_UNSIGNED_BYTE, imageData);
// Release context
CGContextRelease(imgcontext);
// Free Stuff
free(imageData);
[image release];
[texData release];

// Create and return texture

tex.texture=texture;
tex.width=width;
tex.height=height;
//= new Texture2D(texture,width, height);
return tex;
}



GLuint makeTexture(NSString* path){
GLuint texture[1]={-1};
glGenTextures(1, texture);
glBindTexture(GL_TEXTURE_2D, texture[0]);

glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);



path = [[NSBundle mainBundle] pathForResource:path ofType:@"png"];
NSData *texData = [[NSData alloc] initWithContentsOfFile:path];
UIImage *image = [[UIImage alloc] initWithData:texData];
if (image == nil)
NSLog(@"Do real error checking here");

GLuint width = CGImageGetWidth(image.CGImage);
GLuint height = CGImageGetHeight(image.CGImage);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
void *imageData = malloc( height * width * 4 );
CGContextRef context = CGBitmapContextCreate( imageData, width, height, 8, 4 * width, colorSpace, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big );
CGColorSpaceRelease( colorSpace );
CGContextClearRect( context, CGRectMake( 0, 0, width, height ) );
CGContextTranslateCTM( context, 0, height - height );
CGContextDrawImage( context, CGRectMake( 0, 0, width, height ), image.CGImage );

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, imageData);

CGContextRelease(context);

free(imageData);
[image release];
[texData release];

return texture[0];
}



I'd appreciate any help you can offer! I'm loving learning OpenGL, there's an awful lot to learn!

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Alright, figured out problem # 1 and finally I'm displaying textures!!

All you need to do is add glEnable(GL_TEXTURE_2D); to the drawTexture() function- and the texture will be drawn (here's my fail face)

Still having trouble with the draw_rect() function, but I'll let you know what I find.

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