/*!***************************************************************************
@Function GenerateBackgroundTexture
@Input uiScreenWidth
@Input uiScreenHeight
@Description Generates a simple background texture procedurally.
*****************************************************************************/
void OGLES2IntroducingPrint3D::GenerateBackgroundTexture(unsigned int uiScreenWidth, unsigned int uiScreenHeight)
{
// Generate star texture
unsigned int uiStarW = PVRTGetPOTHigher(uiScreenWidth, 1);
unsigned int uiStarH = PVRTGetPOTHigher(uiScreenHeight, 1);
glGenTextures(1, &m_uiStarTex);
glBindTexture(GL_TEXTURE_2D, m_uiStarTex);
PVRTuint8* pTexData = new PVRTuint8[uiStarW*uiStarH];
memset(pTexData, 0, uiStarW*uiStarH);
for (unsigned int uiY = 0; uiY < uiStarH; uiY++)
{
for (unsigned int uiX = 0; uiX < uiStarW; uiX++)
{
unsigned int uiIdx = (uiY*uiStarW+uiX);
if(rand() % 200 == 1)
{
pTexData[uiIdx] = rand() % 255;
}
}
}
glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, uiStarW, uiStarH, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, pTexData);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
delete [] pTexData;
bool bRotate = PVRShellGet(prefIsRotated) && PVRShellGet(prefFullScreen);
m_BG.Init(NULL, bRotate, NULL);
}
// NOTE: This function should be optimised
unsigned int PVRTGetPOTLower(unsigned int uiOriginalValue, int iTimesLower)
{
if(uiOriginalValue == 0 || iTimesLower < 0)
{
return 0;
}
unsigned int uiSize = PVRTGetPOTHigher(uiOriginalValue,1);
uiSize >>= 1;//uiSize /=2;
for(int i = 1; i < iTimesLower; ++i)
{
uiSize >>= 1;//uiSize /=2;
if(uiSize == 1)
{
// Lowest possible value has been reached, so break
break;
}
}
return uiSize;
}