PNG to Opengl usage issues - c++

Question

I'm trying to collate several native PNG images into Opengl & I'm having some roadblocks. I'm already using a Cximage library, so would prefer to stick to this if I can help it.
3 related issues;
PNGs are showing as black & white in OpenGL. The image isn't the issue as Other image types work but I'd rather not convert unless it's easy & doesn't require disk saving or another library.
PNG having black background which are suppose to be transparent.
OpenGL view/Orientation issue. Image is skewed in OpenGL ie not orientated properly. The PNGs contain isometric views, which I'm trying to display.
Sample of code I am currently using;
*And Yes I realise I'm using depreciated Opengl. I need to due to legacy code I am working with.
int MyScene::LoadTexture
{
m_pImgCol = new CxImage((BYTE *)pdatabuffer, (DWORD)filesize, CXIMAGE_FORMAT_PNG);
DWORD iDest(0), iSrc(0);
DWORD dwSize = m_pImgCol->GetWidth()*m_pImgCol->GetHeight();
BYTE *pSrc = m_pImgCol->GetBits();
BYTE *pDest = new BYTE[dwSize * 4];
BYTE *pSrcA = m_pImgAlpha ? m_pImgAlpha->GetBits() : NULL;
BYTE alpha;
for (DWORD iX = 0; iX<dwSize; iX++)
{
alpha = 255;
if (pSrcA)
alpha = pSrcA[iX];
else
{
if (pSrc[iSrc] == 0 && pSrc[iSrc + 1] == 0 && pSrc[iSrc + 2] == 0)
alpha = 0;
}
pDest[iDest++] = pSrc[iSrc++];
pDest[iDest++] = pSrc[iSrc++];
pDest[iDest++] = pSrc[iSrc++];
pDest[iDest++] = alpha;
}
GLuint iTexture=0;
glGenTextures(1, &iTexture);
glBindTexture(GL_TEXTURE_2D, 0);
glTexImage2D(GL_TEXTURE_2D, 0, 4, m_pImgCol->GetWidth(), m_pImgCol->GetHeight(), 0, GL_RGBA, GL_UNSIGNED_BYTE, pDest);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glEnable(GL_TEXTURE_2D);
}
int MyScene::DrawGLScene()
{
CRect rWnd;
GetClientRect(&rWnd);
glViewport(0,0,rWnd.Width(),rWnd.Height());
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-20 * m_Zoom, 20 * m_Zoom, -15 * m_Zoom, 25 * m_Zoom, 20000, -20000);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glEnable(GL_TEXTURE_2D);
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
glTranslatef(0, -0.5f, 0.0f);
glRotatef(m_rx, 1.0f, 0.0f, 0.0f);
glRotatef(m_rz, 0.0f, 0.0f, 1.0f);
glRotatef(m_ry, 0.0f, 1.0f, 0.0f);
DrawScene();
SwapBuffers(m_pView->m_hDC);
return TRUE;
}
int MyScene::DrawScene
{
float dL = -8;
float dR = 8;
float dT = -8;
float dB = 8;
glBindTexture(GL_TEXTURE_2D, 0);
glColor3f(1.0f, 1.0f, 1.0f);
glBegin(GL_QUADS);
glVertex3f(dL, dT, 0);
glTexCoord2f(0, 0);
glVertex3f(dL, dB, 0);
glTexCoord2f(0, 1);
glVertex3f(dR, dB, 0);
glTexCoord2f(1, 1);
glVertex3f(dR, dT, 0);
glTexCoord2f(1, 0);
glEnd();
}
If necessary I can provide more code, but this is as basic as I can break it down to.

Answer 1

Found http://ysflight.in.coocan.jp/programming/pngdecoder/pngdecodere.html & modified it to read existing buffer. Minimal fuss, no disk saving or library.
got PNG transparency working by adding;
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
Imaging tearing; seems I had following in wrong order;
glTexCoord2f(0, 0);
glVertex3f(dL, dT, 0);