Correct alpha channel drawing in OpenGl

Question

After loading the image, I have separate bytes for each channel loaded into an array of unsigned characters. He passed a function that projects it as a texture onto a square. Everything seems to be working fine except for the alpha channel, which appears as the background color. I use OpenGL to draw an image. Do I get benefits by adding a layering mechanism? Also, how can I achieve the transparent effect that I want?

Note. This is the code that cheats on me:

void SetUpView()
{
    // Set color and depth clear value
    glClearDepth(1.f);
    glClearColor(1.f, 0.f, 0.f, 0.f);

    // Enable Z-buffer read and write
    glEnable(GL_DEPTH_TEST);
    glEnable(GL_TEXTURE_2D);
    glDepthMask(GL_TRUE);

    glEnable (GL_BLEND); 
    glBlendFunc (GL_ONE, GL_ONE_MINUS_SRC_ALPHA);

    // Setup a perspective projection
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(90.f, 1.f, 1.f, 500.f);
};

Also, here is the code for quad rendering.

void DrawTexturedRect(RectBounds *Verts, Image *Texture)
{
    glBindTexture(GL_TEXTURE_2D, GetTextureID(Texture));

    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    glPixelZoom(1, -1);

    glBegin(GL_QUADS);
    glTexCoord2f(0.0, 1.0);
    glVertex3f(Verts->corners[0].x, Verts->corners[0].y, Verts->corners[0].z);

    glTexCoord2f(1.0, 1.0);
    glVertex3f(Verts->corners[1].x, Verts->corners[1].y, Verts->corners[1].z);

    glTexCoord2f(1.0, 0.0);
    glVertex3f(Verts->corners[2].x, Verts->corners[2].y, Verts->corners[2].z);

    glTexCoord2f(0.0, 0.0);
    glVertex3f(Verts->corners[3].x, Verts->corners[3].y, Verts->corners[3].z);
    glEnd();
};

The Image class contains an array of unsigned characters obtained using OpenIL.

Relevant Code:

loaded = ilLoadImage(filename.c_str());
ilConvertImage(IL_RGBA, IL_UNSIGNED_BYTE);

unsigned char *bytes = ilGetData();

//NewImage is an instance of an Image. This is returned and passed to the above function.
NewImage->data = bytes;

Problem http://img375.imageshack.us/img375/9585/j120192.png

thank

Answer 1

- , :

glDepthMask(false);

:

glDepthMask(true);

, .

Answer 2

glClearColor (1.f, 0.f, 0.f, 0.f);

, RGBA, red 1.0.

, ?

Answer 3

Try:

glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

: , . , ( Z-, ) . , Z- - , .