void translate2D(GLfloat tx, GLfloat ty)
{
Matrix3x3 matTransl;
matrix3x3SetIndentity(matTransl);
matTransl[0][2] = tx;
matTransl[1][2] = ty;
matrix3x3PreMultiply(matTransl, matComposite);
}
void translate2D (GLfloat tx, GLfloat ty)
{
Matrix3x3 matTransl;
/* Initialize translation matrix to identity. */
matrix3x3SetIdentity (matTransl);
matTransl [0][2] = tx;
matTransl [1][2] = ty;
/* Concatenate matTransl with the composite matrix. */
matrix3x3PreMultiply (matTransl, matComposite);
}
void scale2D(GLfloat sx, GLfloat sy, wcPt2D fixedPt)
{
Matrix3x3 matScale;
matrix3x3SetIndentity(matScale);
matScale[0][0] = sx;
matScale[0][2] = (1 - sx) * fixedPt.x;
matScale[1][1] = sy;
matScale[1][2] = (1 - sy) * fixedPt.y;
/* concatenate matScale with the composite matrix */
matrix3x3PreMultiply(matScale, matComposite);
}
void scale2D (GLfloat sx, GLfloat sy, wcPt2D fixedPt)
{
Matrix3x3 matScale;
/* Initialize scaling matrix to identity. */
matrix3x3SetIdentity (matScale);
matScale [0][0] = sx;
matScale [0][2] = (1 - sx) * fixedPt.x;
matScale [1][1] = sy;
matScale [1][2] = (1 - sy) * fixedPt.y;
/* Concatenate matScale with the composite matrix. */
matrix3x3PreMultiply (matScale, matComposite);
}
void rotate2D(wcPt2D pivotPt, GLfloat theta)
{
Matrix3x3 matRot;
matrix3x3SetIndentity(matRot);
matRot[0][0] = cos(theta);
matRot[0][1] = -sin(theta);
matRot[0][2] = pivotPt.x * (1 - cos(theta));
matRot[1][0] = sin(theta);
matRot[1][1] = cos(theta);
matRot[1][2] = pivotPt.y * (1 - sin(theta));
matrix3x3PreMultiply(matRot, matComposite);
}
void rotate2D (wcPt2D pivotPt, GLfloat theta)
{
Matrix3x3 matRot;
/* Initialize rotation matrix to identity. */
matrix3x3SetIdentity (matRot);
matRot [0][0] = cos (theta);
matRot [0][1] = -sin (theta);
matRot [0][2] = pivotPt.x * (1 - cos (theta)) +
pivotPt.y * sin (theta);
matRot [1][0] = sin (theta);
matRot [1][1] = cos (theta);
matRot [1][2] = pivotPt.y * (1 - cos (theta)) -
pivotPt.x * sin (theta);
/* Concatenate matRot with the composite matrix. */
matrix3x3PreMultiply (matRot, matComposite);
}
