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JOGL Transform Functions

JOGL transformation is a mechanism that provides special effect to graphical objects. These effects are applied after the creation of an image. Following are the frequently used transformation functions: –

glLoadIdentity()

• The glLoadIdentity() method replaces the current transformation matrix with the identity matrix
• It can reset the current transformation matrix before performing a transformation.

glTranslate()

• The glTranslate() method multiplies the current matrix by a translation matrix.
• To translate an object the following syntax is used: –

Here,

x,y,z – The x, y, z represents as a coordinate of translation vector.

glPushMatrix()

• The glPushMatrix() pushes the current matrix stack down by one.
• After the invoking of glPushMatrix() method, the matrix on top of the stack is similar to its below one.

glPopMatrix()

• The glPopMatrix() pop the current matrix stack.
• To pop current matrix, it replaces the current matrix with the one below it on the stack.

glOrtho() method

• The glOrtho() method multiply the current matrix into orthographic matrix.
• It produces the parallel projection of an image in 3D space.
• Syntax:-

Here,

l, r – It specify the left and right vertical clipping planes coordinates.

b, t – It specify the bottom and top horizontal clipping planes coordinates.

nearVal, farVal – It specify the distance to the near and farther depth clipping plane.

glViewport()

• The glViewport() method is used to set the view of an image that represents the visible area of display.
• The following syntax is used to set the view: –

Here,

x, y – Specifies the lower left corner of the viewport rectangle.

w, h – Specifies the width and height of the port.

Now, we will learn some important transformation functions in detail.