void GLMath::_glFrustum(float left, float right, float bottom, float top, float nearZ, float farZ)
{
float deltaX = right - left;
float deltaY = top - bottom;
float deltaZ = farZ - nearZ;
Matrix4X4 *r;
DEBUG_NOTIFICATION("glFrustum(%f, %f, %f, %f, %f, %f\n", left, right, bottom, top, nearZ, farZ);
r = getMatrix(matrixmode);
if ( (nearZ <= 0.0f) || (farZ <= 0.0f) ||
(deltaX <= 0.0f) || (deltaY <= 0.0f) || (deltaZ <= 0.0f) )
return;
_glLoadIdentity(r);
r->m[0][0] = 2.0f * nearZ / deltaX;
//r->m[0][1] = r->m[0][2] = r->m[0][3] = 0.0f;
r->m[1][1] = 2.0f * nearZ / deltaY;
//r->m[1][0] = r->m[1][2] = r->m[1][3] = 0.0f;
r->m[2][0] = (right + left) / deltaX;
r->m[2][1] = (top + bottom) / deltaY;
r->m[2][2] = -(nearZ + farZ) / deltaZ;
r->m[2][3] = -1.0f;
r->m[3][2] = -2.0f * nearZ * farZ / deltaZ;
//r->m[3][0] = r->m[3][1] = r->m[3][3] = 0.0f;
r->m[3][3] = 0.0f;
//_glMatrixMultiply(r, r, &frust);
}
void GLMath::_glLoadIdentity()
{
Matrix4X4 *r;
DEBUG_INFO("_glLoadIdentity()\n");
r = getMatrix(matrixmode);
_glLoadIdentity(r);
}
void gl_CreateScreen() {
int vsize = (screen_height/MaxLines)*MaxLines;
int vpos, hoffset, maxheight;
int maxstretch = (screen_width * 3) / 40;
if (vsize+Tall*4 > screen_height) maxheight = screen_height;
else maxheight = vsize+Tall*4;
if (Narrow > maxstretch) hoffset = maxstretch*4;
else hoffset = Narrow*4;
vpos = (screen_height - maxheight)/2;
_glEnable( GL_TEXTURE_2D );
_glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
_glViewport( -hoffset, vpos, screen_width+hoffset*2, maxheight );
_glMatrixMode( GL_PROJECTION );
_glLoadIdentity();
_glOrtho( 0, screen_width, screen_height, 0, -1, 1 );
_glMatrixMode( GL_MODELVIEW );
_glLoadIdentity();
}
void GLMath::_glOrtho(float left, float right, float bottom, float top, float nearZ, float farZ)
{
float deltaX = right - left;
float deltaY = top - bottom;
float deltaZ = farZ - nearZ;
Matrix4X4 *r;
if ( (deltaX == 0.0f) || (deltaY == 0.0f) || (deltaZ == 0.0f) )
return;
r = getMatrix(matrixmode);
_glLoadIdentity(r);
r->m[0][0] = 2.0f / deltaX;
r->m[3][0] = -(right + left) / deltaX;
r->m[1][1] = 2.0f / deltaY;
r->m[3][1] = -(top + bottom) / deltaY;
r->m[2][2] = -2.0f / deltaZ;
r->m[3][2] = -(nearZ + farZ) / deltaZ;
//_glMatrixMultiply(result, &ortho, result);
}
