The size of the annotation on the axes may be set, relative to CHARSIZE, with xCHARSIZE, where x is X, Y, or Z. This keyword does not apply when hardware (i.e.
The overall character size for the annotation when Hershey fonts are selected. channel 3 is the 8-bit frame buffer containing the blue channelĪccepted by: AXIS Procedure, CONTOUR Procedure, PLOT Procedure, SHADE_SURF Procedure, SURFACE Procedure, XYOUTS Procedure.channel 2 is the 8-bit frame buffer containing the green channel.channel 1 is the 8-bit frame buffer containing the red channel.channel 0 specifies three 8-bit frame buffers containing the red, green, and blue channels.When using the Z buffer device with a pixel depth of 24 bits per pixel: When using the Z buffer device with a pixel depth of 8 bits per pixel: The position parameters (0, 0 above) can be altered to write to any location in the window. If neither keyword parameter is present, the 8-bit image is written to all three-color channels, yielding the same effect as if the channel parameter is specified as 0.įor example, to transfer three 8-bit images contained in the arrays R, G, and B to their respective channels, use the following statements: Load red in channel 1: TV, R, 0, 0, 1 Load green in channel 2: TV, G, 0, 0, 2 Load blue in channel 3: TV, B, 0, 0, 3 The CHANNEL parameter specifies the source or destination channel number for 8-bit images, and the TRUE keyword TrueColor Images) indicates for 24-bit images the method of channel interleaving. Images can be transferred to and from the display in either 8-bit or 24-bit mode. Note: CONTOUR, PLOT, SHADE_SURF, and SURFACE also accept the CHANNEL keyword, but pass it to ERASE. If omitted, !P.CHANNEL contains the default channel value. When using a “decomposed” display system, the red channel is 1, the green channel is 2, and the blue channel is 3. This parameter is ignored on display systems that have only one memory channel. This keyword specifies the memory channel for the operation.
Note: If the NOERASE keyword (or !P.NOERASE) is set, the value of the BACKGROUND keyword (or !P.BACKGROUND) is ignored.Īccepted by: ERASE Procedure, TV Procedure, TVRD, TVSCL Procedure. Not all devices support erasing the background to a specified color.įor example, to produce a black plot with a white background on an indexed-color display: PLOT, Y, BACKGROUND = 255, COLOR = 0 The background color index or 24-bit color value to which all pixels are set when erasing the screen or page.
The following graphics keywords are discussed in this page:Īccepted by: CONTOUR Procedure, PLOT Procedure, SURFACE Procedure, System variable equivalent: !P.BACKGROUND. The system variable fields that control this are !X.CHARSIZE, !Y.CHARSIZE, and !Z.CHARSIZE.
For example, CHARSIZE refers to the three keywords XCHARSIZE, YCHARSIZE, and ZCHARSIZE, which control the size of the characters annotating the three axes. The axis keywords are shown in the form NAME. These keywords correspond to fields in the axis system variables: !X, !Y, and !Z, and are described in more detail in Graphics System Variables. The keywords that control the plot axes are prefixed with the character ‘X’, ‘Y’, or ‘Z’ depending on the axis in question. Keywords that have a direct correspondence to fields in a system variable (usually !P) are also indicated. The name of each keyword is followed by a list of routines that accept that keyword. Routine-specific keywords are documented in the description of the routine.The graphics keywords are described below. Therefore, instead of describing each keyword along with the description of each routine, this section contains a brief summary of each graphics keyword. The IDL Direct G raphics routines, CURSOR, ERASE, PLOTS, POLYFILL, TV (and TVSCL), TVCRS, TVRD, and XYOUTS, and the plotting procedures, AXIS, CONTOUR, PLOT, OPLOT, SHADE_SURF, and SURFACE, accept a number of common keywords.