EDIT: I just fixed the problem
turns out you cant bind the textures inside glBegin/glEnd.
Ill leave this here in case it helps someone else.
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hey guys,
im writing a simple particle engine at the moment, and all was going well until i tried to implement animated particles. Basically what im trying to do is load multiple textures like this
glGenTextures(STAR_NUM_FRAMES, 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);
LoadBMP("star/star001.bmp");
glBindTexture(GL_TEXTURE_2D, texture[1]);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
LoadBMP("star/star002.bmp");
glBindTexture(GL_TEXTURE_2D, texture[2]);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
LoadBMP("star/star003.bmp");
glBindTexture(GL_TEXTURE_2D, texture[3]);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
LoadBMP("star/star004.bmp");
(here is the LoadBMP code i am using...i got it off the net so im pretty sure its ok
///////////////////////////////////////////////////////////////////////////////
// This function loads a 24-bit color Windows bitmap and sets it as the current
// texture. The bitmap must be 24-bit color, and the dimensions must be powers
// of 2 (no additional checks are performed).
BOOL LoadBMP(TCHAR* szFileName)
{
HANDLE hFileHandle;
BITMAPINFO *pBitmapInfo = NULL;
unsigned long lInfoSize = 0;
unsigned long lBitSize = 0;
int nTextureWidth;
int nTextureHeight;
BYTE *pBitmapData;
// Open the Bitmap file
hFileHandle = CreateFile(szFileName,GENERIC_READ,FILE_SHARE_READ,
NULL,OPEN_EXISTING,FILE_FLAG_SEQUENTIAL_SCAN,NULL);
// Check for open failure (most likely file does not exist).
if(hFileHandle == INVALID_HANDLE_VALUE)
return FALSE;
// File is Open. Read in bitmap header information
BITMAPFILEHEADER bitmapHeader;
DWORD dwBytes;
ReadFile(hFileHandle,&bitmapHeader,sizeof(BITMAPFILEHEADER),
&dwBytes,NULL);
__try {
if(dwBytes != sizeof(BITMAPFILEHEADER))
return FALSE;
// Check format of bitmap file
if(bitmapHeader.bfType != 'MB')
return FALSE;
// Read in bitmap information structure
lInfoSize = bitmapHeader.bfOffBits - sizeof(BITMAPFILEHEADER);
pBitmapInfo = (BITMAPINFO *) new BYTE[lInfoSize];
ReadFile(hFileHandle,pBitmapInfo,lInfoSize,&dwBytes,NULL);
if(dwBytes != lInfoSize)
return FALSE;
nTextureWidth = pBitmapInfo->bmiHeader.biWidth;
nTextureHeight = pBitmapInfo->bmiHeader.biHeight;
lBitSize = pBitmapInfo->bmiHeader.biSizeImage;
if(lBitSize == 0)
lBitSize = (nTextureWidth *
pBitmapInfo->bmiHeader.biBitCount + 7) / 8 *
abs(nTextureHeight);
// Allocate space for the actual bitmap
pBitmapData = new BYTE[lBitSize];
// Read in the bitmap bits
ReadFile(hFileHandle,pBitmapData,lBitSize,&dwBytes,NULL);
if(lBitSize != dwBytes)
{
if(pBitmapData)
delete [] (BYTE *) pBitmapData;
pBitmapData = NULL;
return FALSE;
}
}
__finally // Fail or success, close file and free working memory
{
CloseHandle(hFileHandle);
if(pBitmapInfo != NULL)
delete [] (BYTE *)pBitmapInfo;
}
// This is specific to the binary format of the data read in.
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);
glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
glTexImage2D(GL_TEXTURE_2D, 0, 3, nTextureWidth, nTextureHeight, 0,
GL_BGR_EXT, GL_UNSIGNED_BYTE, pBitmapData);
if(pBitmapData)
delete [] (BYTE *) pBitmapData;
return TRUE;
}
Now basically i have a frame counter for each particle that i increment depending on how much time has passed since the last time i rendered that particular particle. I use the frame counter (p->currentFrame) as the index in the texture array... as below...
glPushMatrix();
glEnable(GL_TEXTURE_2D); // Enable Texture Mapping
glShadeModel(GL_SMOOTH); // Enable Smooth Shading
glEnable(GL_DEPTH_TEST);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glBegin(GL_QUADS);
while(p)
{
GLfloat size = p->size/2;
CVector pos = p->position;
glBindTexture(GL_TEXTURE_2D, texture[p->currentFrame]);
glColor4fv(p->colour);
glTexCoord2f(0.0, 0.0); glVertex3fv((pos + (right + up) * -size).v);
glTexCoord2f(1.0, 0.0); glVertex3fv((pos + (right - up) * size).v);
glTexCoord2f(1.0, 1.0); glVertex3fv((pos + (right + up) * size).v);
glTexCoord2f(0.0, 1.0); glVertex3fv((pos + (up - right) * size).v);
p = p->next;
}
glEnd();
glPopMatrix();
glDisable(GL_BLEND);
ive looked it up on the net, and all the code i could find does it this way (or something similar). But for some reason, the texture shown on screen is always the last one loaded. What am i doing wrong?
[Edited by - jamesbf on November 7, 2005 11:21:04 PM]
