Projection matrix issue (using a coded 4x4)

OpenGL OpenGL: Advanced Coding
1

The below matrix set up works until I hit the projection matrix. Until that point the square shows up flat - nearly in the middle of the screen. After adding the proj_mat, depending on the calcs I use I get differing results. Normally, I can’t see the graphic - some of the calculations I tried allow me to see the square if I roll around an angle, but it’s never where I expect it to be. I’ve tried multiple solutions
http://www.songho.ca/opengl/gl_projectionmatrix.html
http://www.geeks3d.com/20090729/howto-perspective-projection-matrix-in-opengl/
http://ogldev.atspace.co.uk/www/tutorial12/tutorial12.html


glViewport(0.0f, 0.0f, width, height);
    glEnable(GL_DEPTH_TEST);

.....

        GLfloat x_roll_floaters[4][4] = {
        {1.0f, 0.0f, 0.0f, 0.0f},
        {0.0f, cos((x_roll_angle*3.141592654)/180), sin((x_roll_angle*3.141592654)/180), 0.0f},
        {0.0f, -sin((x_roll_angle*3.141592654)/180), cos((x_roll_angle*3.141592654)/180), 0.0f},
        {0.0f, 0.0f, 0.0f, 1.0f}
        };
        GLfloat y_roll_floaters[4][4] = {
        {cos((y_roll_angle*3.141592654)/180), 0.0f, -sin((y_roll_angle*3.141592654)/180), 0.0f},
        {0.0f, 1.0f, 0.0f, 0.0f},
        {sin((y_roll_angle*3.141592654)/180), 0.0f, cos((y_roll_angle*3.141592654)/180), 0.0f},
        {0.0f, 0.0f, 0.0f, 1.0f}
        };
         GLfloat z_roll_floaters[4][4] = {
        {cos((z_roll_angle*3.141592654)/180), sin((z_roll_angle*3.141592654)/180), 0.0f, 0.0f},
        {-sin((z_roll_angle*3.141592654)/180), cos((z_roll_angle*3.141592654)/180), 0.0f, 0.0f},
        {0.0f, 0.0f, 1.0f, 0.0f},
        {0.0f, 0.0f, 0.0f, 1.0f}
        };
         GLfloat view_floaters[4][4] = {
       /*right  up   look*/
        {1.0f, 0.0f, 0.0f, 0.0f},
        {0.0f, 1.0f, 0.0f, 0.0f},
        {0.0f, 0.0f, 1.0f, 0.0f},
        {0.0f, 0.0f, 0.0f, 1.0f}
        };
 GLfloat proj_floaters[4][4] = {
        {0.138f/1.777f, 0.0f, 0.0f, 0.0f},
        {0.0f, 0.222f, 0.0f, 0.0f},
        {0.0f, 0.0f, -1.0f, -0.2f},
        {0.0f, 0.0f, -1.0f, 0.0f}
        };

vertex shader


mat4 model = z_roll * y_roll * x_roll;/
gl_Position = proj_mat * view_mat * model * vec4(position, 1.0f);/

Graphic


0.2f, 0.2f, -1.0f,
0.2f, 0.4f, -1.0f,
-0.2f, 0.4f, -1.0f,
-0.2f, 0.2f, -1.0f

Thanks.

2

Are you transposing the matrices when passing them to OpenGL?

By default, GL expects matrices in column-major order, but C uses row-major order, so you need to set the [var]transpose[/var] parameter to glUniformMatrix*fv() to [var]GL_TRUE[/var].

If you fail to do that, the only effect upon the rotation matrices will be to reverse the rotation direction, but the projection matrix will be garbage.

3

Wonderful, will give that a try later tonight.
I thought it automatically changed to column-major.

Ty much.