Hello,
I've ported 1-1 this code from C++/OpenGL to C# SharpGL:
float[] cameraAngle = { 0, 0, 0 };
float[] cameraPosition = { 0, 0, 10 };
float[] modelPosition = { 0, 0, 0 };
float[] modelAngle = { 0, 0, 0 };
float[] matrixView = new float[16];
float[] matrixModel = new float[16];
float[] matrixModelView = new float[16];
// clear buffer
gl.ClearColor(0.1f, 0.1f, 0.1f, 1);
gl.Clear(OpenGL.COLOR_BUFFER_BIT | OpenGL.DEPTH_BUFFER_BIT | OpenGL.STENCIL_BUFFER_BIT);
// initialze ModelView matrix
gl.PushMatrix();
gl.LoadIdentity();
// ModelView matrix is product of viewing matrix and modeling matrix
// ModelView_M = View_M * Model_M
// First, transform the camera (viewing matrix) from world space to eye space
// Notice all values are negated, because we move the whole scene with the
// inverse of camera transform
gl.Rotate(-cameraAngle[0], 1, 0, 0); // pitch
gl.Rotate(-cameraAngle[1], 0, 1, 0); // heading
gl.Rotate(-cameraAngle[2], 0, 0, 1); // roll
gl.Translate(-cameraPosition[0], -cameraPosition[1], -cameraPosition[2]);
// we have set viewing matrix upto this point. (Matrix from world space to eye space)
// save the view matrix only
gl.GetFloat(OpenGL.MODELVIEW_MATRIX, matrixView); // save viewing matrix
//=========================================================================
// always Draw the grid at the origin (before any modeling transform)
//DrawGrid(10, 1);
// In order to get the modeling matrix only, reset OpenGL.MODELVIEW matrix
gl.LoadIdentity();
// transform the object
// From now, all transform will be for modeling matrix only. (transform from object space to world space)
gl.Translate(modelPosition[0], modelPosition[1], modelPosition[2]);
gl.Rotate(modelAngle[0], 1, 0, 0);
gl.Rotate(modelAngle[1], 0, 1, 0);
gl.Rotate(modelAngle[2], 0, 0, 1);
// save modeling matrix
gl.GetFloat(OpenGL.MODELVIEW_MATRIX, matrixModel);
//=========================================================================
// re-strore OpenGL.MODELVIEW matrix by multiplying matrixView and matrixModel before drawing the object
// ModelView_M = View_M * Model_M
gl.LoadMatrixf(matrixView); // Mmv = Mv
gl.MultMatrixf(matrixModel); // Mmv *= Mm
// save ModelView matrix
gl.GetFloat(OpenGL.MODELVIEW_MATRIX, matrixModelView);
//=========================================================================
// Draw a teapot after ModelView transform
// v' = Mmv * v
//DrawAxis(4);
//DrawTeapot();
gl.PopMatrix();
It doesn't look like the ModelView matrix gets multiplied, the result is the Identity Matrix!
What could be wrong??
Thanks