MiniRobotLanguage (MRL)
GPC. Command
Get Pixel Color
Intention
This command reads the screen color of a pixel in a window. You can specify coordinates in Screen- (desktop), or in window-coordinates.
You will also get the red, green and blue parts of the color (in this order) on the Stack.
In the simplest way you can check the Pixel-color at some point like this:
GPC.624,794
STS.DUMP
And this is what you may find on TOS.
First on Top, the 24-bit color value. Then next, the Blue-($$001),Green-($$002), and the Red ($$003)-Part of the Pixel-color.
If you just need the color value, you can get it using the $$000 Stackvariable.
GPC.624,794
PRT.The 24-bit color is: $$000
STS.DUMP
MBX.!
Or you can just add one Parameter with a variable. The following Sample shows it. And it also shows that you can use a Point-Variable instead of two coordinated here.
VAP.$$COR=624,794
GPC.$$COR|$$COL
PRT.The 24-bit color is: $$COL
STS.DUMP
MBX.!
ENR.
Syntax
GPC.[P1][|P2]
GPC.[proto]|P1,P2
Parameter Explanation
P1 - (optional) prototype coordinates
P2 - (optional) coordinates separated with ","
P3 - (optional) takes the pixel-colour, if omitted stack is used.
There are three prototypes:
- c - Childwindow Coordinates (you can use "o" for this one also.)
- a - actual window coordinates
- t - Top-Window Coordinates
If prototype is omitted, Screen-Coordinates are taken.
Example
'***********************************
' GPC.-Demo
'***********************************
GPC.1028,1370
STS.DUMP
$$COL=$$000
VTH.$$COL
PRT.The 24-bit color is: $$COL
MBX.!
END.
'***********************************
' GPC.-Demo
'***********************************
JSR.closeNotepads
EXO.notepad
STW.p|#pid#
SCW.c|edit
MMV.o|50,100
STS.CLEAR
' Get colour from Child-Window-Coord's
VAP.§§AAA=50,100
GPC.c|§§AAA
JSR.showcol
' Get colour from Top-Window-Coord's
VAP.§§AAA=50,100
GPC.t|§§AAA
JSR.showcol
' Get Screen-Color
VAP.§§AAA=50,100
GPC.s|§§AAA
JSR.showcol
MBX.!
' Get Screen-Color and show Stack-Order
VAP.§§AAA=50,100
GPC.s|§§AAA
STS.DUMP
MBX.!
' Show Speed-Dump
DMP.
MBX.!
END.
:showcol
PRT.----------------------
PRT. Red is: $$003
PRT. Green is: $$002
PRT. Blue is: $$001
$$COL=$$000
VTH.$$COL
PRT. Pixel-Color is: $$COL
PRT.----------------------
RET.
:closeNotepads
STW.ctwo|notepad|Editor|0|overcn
CLW.
JMP.closeNotepads
:overcn
RET.
Remarks
Instead of using separate variables for X and Y, you can also use a Point-Variable, where x and y values are separated by a "," as follows:
VAR.§§PAP=10,10
GPC.§§PRE|§§PAP|§§COL
Limitations:
The RGB-Splitter works default with 24- or 32 bit colors. It will not work with 8 or 16 bit color depth.
See also:
• 1.8. Selecting the Application (Topwindow)
• IPC. / NPC. - If-Pixel-Colour