D2TransformSave and D2TransformRestore command

Requires: Direct2D.lg32

Purpose

Saves and restores a render target's transformation setting.

Syntax

D2TransformSave
D2TransformRestore

Description

D2TransformSave saves the current transformation setting. D2TransformRestore restores the previously saved transformation setting. These commands should be within the D2BeginDraw and D2EndDraw commands. Saving and restoring the current (complex) setting will prevent the recalculation of a complex transformation later on. A D2TransformSave should always match a D2TransformRestore command, although D2BeginDraw resets D2TransformSave to the identity matrix.

Example

'

' D2TransformSave/D2TransformRestore sample (dpi-unaware)

'

$Library "direct2d"

Global Object Win1RT

OpenW 1, 0, 0, 320, 300, ~15

Set Win1RT = D2GetRT()

Do

Sleep

Until Me Is Nothing

Sub Win_1_Paint

D2BeginDraw Win1RT, D2C_White

' Show a rotation

D2DefLine 1           ' dotted line

D2ForeColor = D2C_Brown

D2TransformSave       ' pushes current state to a stack

D2Text 40, 10, "Rotation"

D2Box 40, 40, 100, 100      ' original rectangle

D2Transform D2TF_ROTATE, 60, 70, 70   ' rotate 45 degrees around 70,70

D2DefLine 0                 ' straight line

D2Box 40, 40, 100, 100      ' original rectangle, rotated

D2TransformRestore    ' pops most recent state form stack

' Add an offset to restored state

D2TransformAdd D2TF_MOVE, 90, 0    ' Add offset (to restored matrix)

D2Text 40, 10, "Translated"

D2Box 40, 40, 100, 100      ' original rectangle

D2EndDraw

EndSub

Sub Win_1_ReSize

D2ResizeRT Win1RT, _X, _Y

Remarks

D2TransformSave and D2TransformRestore call the ID2D1RenderTarget's transform methods. See D2Transform for more information.

See Also

D2Transform, D2TransformAdd, D2TransformOffset, D2GetRT, D2BeginDraw, D2EndDraw.

{Created by James Gaite; Last updated: 04/03/2021 by James Gaite}