OpenGL Projection matrix won't allow displaying anything

Question

I'm trying to get some basic OpenGL-ES with Shaders to run on the iPhone, based on some examples.

For some reason my projection matrix refuses to result in something on the screen. It feels like a clipping plane is set very near but that contradicts with the values I supply. If I render the same scene with an Orthogonal projection matrix I see my object just no perspective obviously.

Here's the code that generates the projection matrix:

esPerspective(&proj, 45.f, 768.0/1024.0, 1.f, 10000.f);

void esPerspective(ESMatrix *result, float fovy, float aspect, float nearZ, float farZ)
{
   float frustumW, frustumH;

   frustumH = tanf( fovy / 360.0f * PI ) * nearZ;
   frustumW = frustumH * aspect;

   esFrustum( result, -frustumW, frustumW, -frustumH, frustumH, nearZ, farZ );
}

void esFrustum(ESMatrix *result, float left, float right, float bottom, float top, float nearZ, float farZ)
{
    float       deltaX = right - left;
    float       deltaY = top - bottom;
    float       deltaZ = farZ - nearZ;
    ESMatrix    frust;

    if ( (nearZ <= 0.0f) || (farZ <= 0.0f) ||
          (deltaX <= 0.0f) || (deltaY <= 0.0f) || (deltaZ <= 0.0f) )
         return;

    frust.m[0][0] = 2.0f * nearZ / deltaX;
    frust.m[0][1] = frust.m[0][2] = frust.m[0][3] = 0.0f;

    frust.m[1][1] = 2.0f * nearZ / deltaY;
    frust.m[1][0] = frust.m[1][2] = frust.m[1][3] = 0.0f;

    frust.m[2][0] = (right + left) / deltaX;
    frust.m[2][1] = (top + bottom) / deltaY;
    frust.m[2][2] = -(nearZ + farZ) / deltaZ;
    frust.m[2][3] = -1.0f;

    frust.m[3][2] = -2.0f * nearZ * farZ / deltaZ;
    frust.m[3][0] = frust.m[3][1] = frust.m[3][3] = 0.0f;

    esMatrixMultiply(result, &frust, result);
}

My projection matrix comes out as:

[3.21, 0, 0, 0]
[0, 2.41, 0, 0]
[0, 0, -1, -1]
[0, 0, -2, 0]

Even if I manually set the [3][3] cell to 1 I still don't see anything.

Any ideas?

Answer 1

Swap your rows and columns over (ie transpose).

Well your projection matrix is transposed either way. You have a row major projection matrix ...

Answer 2

I'm having the exact same issue as you (using the same esTransform file I'm assuming your using). No matter what I supply as the far plane it is always a far plane of 1.0 it seems. Did you end up figuring out why?