Mapping Operations
[GDI functions]

Defines

• #define GetMapMode(hdc)   GetDCAttr (hdc, DC_ATTR_MAP_MODE)

  Retrieves the current mapping mode of a DC.
  

• #define SetMapMode(hdc, mapmode)   SetDCAttr (hdc, DC_ATTR_MAP_MODE, (DWORD)mapmode)

  Sets the mapping mode of a display context.
  

• #define GetViewportOrg(hdc, pPt)   GetDCLCS(hdc, DC_LCS_VORG, pPt)

  Retrieves the x-coordinates and y-coordinates of the viewport origin for a device context.
  

• #define GetViewportExt(hdc, pPt)   GetDCLCS(hdc, DC_LCS_VEXT, pPt)

  Retrieves the x-extents and y-extents of the current viewport for a device context.
  

• #define GetWindowOrg(hdc, pPt)   GetDCLCS(hdc, DC_LCS_WORG, pPt)

  Retrieves the x-coordinates and y-coordinates of the window for a device context.
  

• #define GetWindowExt(hdc, pPt)   GetDCLCS(hdc, DC_LCS_WEXT, pPt)

  Retrieves the x-extents and y-extents of the current window for a device context.
  

• #define SetViewportOrg(hdc, pPt)   SetDCLCS(hdc, DC_LCS_VORG, pPt)

  Sets the x-coordinates and y-coordinates of the viewport origin for a device context.
  

• #define SetViewportExt(hdc, pPt)   SetDCLCS(hdc, DC_LCS_VEXT, pPt)

  Sets the x-extents and y-extents of the current viewport for a device context.
  

• #define SetWindowOrg(hdc, pPt)   SetDCLCS(hdc, DC_LCS_WORG, pPt)

  Sets the x-coordinates and y-coordinates of the window for a device context.
  

• #define SetWindowExt(hdc, pPt)   SetDCLCS(hdc, DC_LCS_WEXT, pPt)

  Sets the x-extents and y-extents of the current window for a device context.
  

Functions

• MG_EXPORT void GUIAPI GetDCLCS (HDC hdc, int which, POINT *pt)

  Retrieves mapping parameters of a device context.
  

• MG_EXPORT void GUIAPI SetDCLCS (HDC hdc, int which, const POINT *pt)

  Sets mapping parameters of a device context.
  

• MG_EXPORT void GUIAPI DPtoLP (HDC hdc, POINT *pPt)

  Converts device coordinates into logical coordinates.
  

• MG_EXPORT void GUIAPI LPtoDP (HDC hdc, POINT *pPt)

  Converts logical coordinates into device coordinates.
  

• MG_EXPORT void GUIAPI SPtoLP (HDC hdc, POINT *pPt)

  Converts screen coordinates into logical coordinates.
  

• MG_EXPORT void GUIAPI LPtoSP (HDC hdc, POINT *pPt)

  Converts logical coordinates into screen coordinates.
  

---

Detailed Description

end of draw_adv_2d_fns

The mapping mode defines the unit of measure used to transform page-space units into device-space units, and also defines the orientation of the device's x and y axes.

So far, MiniGUI support only two mapping mode:

• MM_TEXT
  Each logical unit is mapped to on device pixel. Positive x is to the right; positive y is down.
• MM_ANISOTROPIC
  Logical units are mapped to arbitrary units with arbitrarily scaled axes; Use SetWindowExt and SetViewportExt functions to specify the units, orientation, and scaling required.

The following formula shows the math involved in converting a point from page space to device space:

      Dx = ((Lx - WOx) * VEx / WEx) + VOx

The following variables are involved:

• Dx x value in device units
• Lx x value in logical units (also known as page space units)
• WO window x origin
• VO viewport x origin
• WE window x-extent
• VE viewport x-extent

The same equation with y replacing x transforms the y component of a point. The formula first offsets the point from its coordinate origin. This value, no longer biased by the origin, is then scaled into the destination coordinate system by the ratio of the extents. Finally, the scaled value is offset by the destination origin to its final mapping.

---

Define Documentation

#define GetMapMode

(

hdc

)

GetDCAttr (hdc, DC_ATTR_MAP_MODE)

Retrieves the current mapping mode of a DC.

This function retrieves the current mapping mode of the DC hdc.

So far, MiniGUI support two mapping modes: MM_TEXT and MM_ANISOTROPIC.

Parameters:

hdc

The device context.

Returns:

The current mapping mode, can be either MM_TEXT or MM_ANISOTROPIC.

See also:

SetWindowExt, SetViewportExt, SetMapMode

Definition at line 4020 of file gdi.h.

#define GetViewportExt	(	hdc,
		pPt		)	GetDCLCS(hdc, DC_LCS_VEXT, pPt)

Retrieves the x-extents and y-extents of the current viewport for a device context.

This function retrieves the x-extents and y-extens of the current viewport of the specified device context hdc.

Parameters:

	hdc	The device context.
	pPt	The viewport extents will be returned through this buffer.

See also:

GetMapMode, SetViewportExt

Definition at line 4126 of file gdi.h.

#define GetViewportOrg	(	hdc,
		pPt		)	GetDCLCS(hdc, DC_LCS_VORG, pPt)

Retrieves the x-coordinates and y-coordinates of the viewport origin for a device context.

This function retrieves the x-coordinates and y-coordinates of the viewport origin of the specified device context hdc.

Parameters:

	hdc	The device context.
	pPt	The viewport origin will be returned through this buffer.

See also:

GetMapMode, SetViewportOrg

Definition at line 4111 of file gdi.h.

#define GetWindowExt	(	hdc,
		pPt		)	GetDCLCS(hdc, DC_LCS_WEXT, pPt)

Retrieves the x-extents and y-extents of the current window for a device context.

This function retrieves the x-extents and y-extens of the current window of the specified device context hdc.

Parameters:

	hdc	The device context.
	pPt	The window extents will be returned through this buffer.

See also:

GetMapMode, SetWindowExt

Definition at line 4156 of file gdi.h.

#define GetWindowOrg	(	hdc,
		pPt		)	GetDCLCS(hdc, DC_LCS_WORG, pPt)

Retrieves the x-coordinates and y-coordinates of the window for a device context.

This function retrieves the x-coordinates and y-coordinates of the window origin of the specified device context hdc.

Parameters:

	hdc	The device context.
	pPt	The window origin will be returned through this buffer.

See also:

GetMapMode, SetWindowOrg

Definition at line 4141 of file gdi.h.

#define SetMapMode	(	hdc,
		mapmode		)	SetDCAttr (hdc, DC_ATTR_MAP_MODE, (DWORD)mapmode)

Sets the mapping mode of a display context.

This function sets the mapping mode of the specified display context hdc.

So far, MiniGUI support two mapping modes: MM_TEXT and MM_ANISOTROPIC.

Parameters:

	hdc	The device context.
	mapmode	The new mapping mode, should be either MM_TEXT or MM_ANISOTROPIC.

Returns:

The old mapping mode, either MM_TEXT or MM_ANISOTROPIC.

See also:

SetWindowExt, SetViewportExt, SetMapMode

Definition at line 4037 of file gdi.h.

#define SetViewportExt	(	hdc,
		pPt		)	SetDCLCS(hdc, DC_LCS_VEXT, pPt)

Sets the x-extents and y-extents of the current viewport for a device context.

This function sets the x-extents and y-extens of the current viewport of the specified device context hdc.

Parameters:

	hdc	The device context.
	pPt	The viewport extents will be set.

See also:

GetMapMode, GetViewportExt

Definition at line 4186 of file gdi.h.

#define SetViewportOrg	(	hdc,
		pPt		)	SetDCLCS(hdc, DC_LCS_VORG, pPt)

Sets the x-coordinates and y-coordinates of the viewport origin for a device context.

This function sets the x-coordinates and y-coordinates of the viewport origin of the specified device context hdc.

Parameters:

	hdc	The device context.
	pPt	The viewport origin will be set.

See also:

GetMapMode, GetViewportOrg

Definition at line 4171 of file gdi.h.

#define SetWindowExt	(	hdc,
		pPt		)	SetDCLCS(hdc, DC_LCS_WEXT, pPt)

Sets the x-extents and y-extents of the current window for a device context.

This function sets the x-extents and y-extens of the current window of the specified device context hdc.

Parameters:

	hdc	The device context.
	pPt	The window extents will be set.

See also:

GetMapMode, GetWindowExt

Definition at line 4216 of file gdi.h.

#define SetWindowOrg	(	hdc,
		pPt		)	SetDCLCS(hdc, DC_LCS_WORG, pPt)

Sets the x-coordinates and y-coordinates of the window for a device context.

This function sets the x-coordinates and y-coordinates of the window origin of the specified device context hdc.

Parameters:

	hdc	The device context.
	pPt	The window origin will be set.

See also:

GetMapMode, GetWindowOrg

Definition at line 4201 of file gdi.h.

---

Function Documentation

void GUIAPI DPtoLP	(	HDC	hdc,
		POINT *	pPt
	)

Converts device coordinates into logical coordinates.

This function converts device coordinates into logical coordinates in the device context hdc.

The conversion depends on the mapping mode of the display context, the settings of the origins and extents for the window and viewport. The x-coordinate and y-coordinate contained in struct pPt will be transformed.

Parameters:

	hdc	The device context.
	pPt	The coordinates to be converted, and the transformed coordinates will be contained in this buffer after the function returns.

See also:

LPtoDP

void GUIAPI GetDCLCS	(	HDC	hdc,
		int	which,
		POINT *	pt
	)

Retrieves mapping parameters of a device context.

This function retrieves mapping paramters of the specified device context hdc when the mapping mode is not MM_TEXT.

Parameters:

	hdc	The device context.
	which	Which parameter you want to retrieve, can be one of the following values:

• DC_LCS_VORG
  Retrieves the x-coordinates and y-coordinates of the viewport origin.
• DC_LCS_VEXT
  Retrieves the x-extents and y-extents of the current viewport.
• DC_LCS_WORG
  Retrieves the x-coordinates and y-coordinates of the window origin.
• DC_LCS_WEXT
  Retrieves the x-extents and y-extents of the window.

Parameters:

pt

The coordinates or extents will be returned through this buffer.

See also:

GetMapMode, SetMapMode, SetDCLCS

void GUIAPI LPtoDP	(	HDC	hdc,
		POINT *	pPt
	)

Converts logical coordinates into device coordinates.

This function converts logical coordinates into device coordinates in the device context hdc.

The conversion depends on the mapping mode of the display context, the settings of the origins and extents for the window and viewport. The x-coordinate and y-coordinate contained in struct pPt will be transformed.

Parameters:

	hdc	The device context.
	pPt	The coordinates to be converted, and the transformed coordinates will be contained in this buffer after the function returns.

See also:

DPtoLP

void GUIAPI LPtoSP	(	HDC	hdc,
		POINT *	pPt
	)

Converts logical coordinates into screen coordinates.

This function converts logical coordinates into screen coordinates in the device context hdc.

The conversion depends on the mapping mode of the display context, the settings of the origins and extents for the window and viewport. The x-coordinate and y-coordinate contained in struct pPt will be transformed.

Parameters:

	hdc	The device context.
	pPt	The coordinates to be converted, and the transformed coordinates will be contained in this buffer after the function returns.

See also:

SPtoLP

void GUIAPI SetDCLCS	(	HDC	hdc,
		int	which,
		const POINT *	pt
	)

Sets mapping parameters of a device context.

This function sets mapping paramters of the specified device context hdc when the mapping mode is not MM_TEXT.

Parameters:

	hdc	The device context.
	which	Which parameter you want to retrieve, can be one of the following values:

• DC_LCS_VORG
  Sets the x-coordinates and y-coordinates of the viewport origin.
• DC_LCS_VEXT
  Sets the x-extents and y-extents of the current viewport.
• DC_LCS_WORG
  Sets the x-coordinates and y-coordinates of the window origin.
• DC_LCS_WEXT
  Sets the x-extents and y-extents of the window.

Parameters:

pt

The coordinates or extents will be set.

See also:

GetMapMode, SetMapMode, GetDCLCS

void GUIAPI SPtoLP	(	HDC	hdc,
		POINT *	pPt
	)

Converts screen coordinates into logical coordinates.

This function converts screen coordinates into logical coordinates in the device context hdc.

The conversion depends on the mapping mode of the display context, the settings of the origins and extents for the window and viewport. The x-coordinate and y-coordinate contained in struct pPt will be transformed.

Parameters:

	hdc	The device context.
	pPt	The coordinates to be converted, and the transformed coordinates will be contained in this buffer after the function returns.

See also:

LPtoSP