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_gEllipse()
Draw an ellipse
------------------------------------------------------------------------------
C Prototype
#include "llibg.api"
void _gEllipse(
int iXCenter,
int iYCenter,
int iRadiusX,
int iRadiusY,
int iStartAngle,
int iEndAngle,
int iMode,
BOOL bFilled,
DWORD dwFillColor,
BOOL bOutlined,
DWORD dwOutlineColor,
int iHeight3D
)
Arguments
iXCenter is the pixel-based X coordinate of the center point.
iYCenter is the pixel-based Y coordinate of the center point.
iRadiusX is the length of the radius, in pixels, along the X axis.
iRadiusY is the length of the radius, in pixels, along the Y axis.
iStartAngle is the starting angle in degrees.
iEndAngle is the final angle in degrees.
iMode is the display mode, which you specify using one of the
following values:
Display Mode Constants
------------------------------------------------------------------------
Constant Display Mode
------------------------------------------------------------------------
LLG_MODE_SET Overwrite existing pixels that are beneath where this
object will be displayed. This is the most common display
mode.
LLG_MODE_AND Perform a logical AND on existing pixels--and on the
display color--that are beneath where this object will be
displayed.
LLG_MODE_OR Perform a logical OR on existing pixels--and on the
display color--that are beneath where this object will be
displayed.
LLG_MODE_XOR Perform a logical XOR on existing pixels--and on the
display color--that are beneath where this object will be
displayed (see Note below).
------------------------------------------------------------------------
Note: LLG_MODE_XOR allows you to move objects around on the screen
without damaging the background. To retrieve the initial background,
simply repeat the function call using the XOR display mode.
bFilled is a flag that you specify as true (.T.) to draw a filled
ellipse.
dwFillColor is the fill color.
bOutlined is a flag that you specify as true (.T.) to draw an
outline around the ellipse.
dwOutlineColor is the outline color.
The range of valid values for all color parameters is limited to the
number of colors available in the selected video mode. For example, in
16-color modes, valid values are between zero and 15, and in 256-color
modes, valid values are between zero and 255.
iHeight3D is a value representing the height of the 3-D effect in
pixels.
Notes
. Restrictions: You cannot use this function unless you have
set the screen to one of the graphic modes using _gModeSet(). This
function respects the screen clipping region as set by _gClipSet().
. Drawing a circle: To draw a circle (which is just a special
case of an ellipse), set the iRadiusX and iRadiusY parameters to the
same value.
. Drawing arcs: Changing the values of iStartAngle and
iEndAngle allows you to draw arcs of a circle or ellipse and sections
of a pie chart.
Files Library is LLIBG.LIB, header file is Llibg.api.
See Also:
_gClipSet()
_gFrame()
_gLine()
_gModeSet()
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