# \[psychtoolbox\] DrawText problem

**URL:** https://psychtoolbox.discourse.group/t/psychtoolbox-drawtext-problem/1509
**Category:** Uncategorized
**Created:** [March 23, 2000, 10:15pm UTC](https://psychtoolbox.discourse.group/t/psychtoolbox-drawtext-problem/1509 "2000-03-23T22:15:06Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Allen\_Ingling](https://avatars.discourse-cdn.com/v4/letter/a/a183cd/32.png) [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)
#### Post date: [March 23, 2000, 10:15pm UTC](https://psychtoolbox.discourse.group/t/psychtoolbox-drawtext-problem/1509/1 "2000-03-23T22:15:06Z")

</div>

I seem to be having a problem with DrawText on one particular computer I  
am using (but not the others). The problem is that text drawn to the  
screen seems broken up and rather illegible. Changing the color of the  
text does odd things, including drawing the text in multiple colors in  
some instances. I will include a sample program, and I'll describe the  
results. At the end of the message is the screentest report for the  
problem computer.  
  
The program is rather simple:  
  
-----  
% first we just define a simple CLUT  
clut = zeros(256, 3);  
BLACK\_INDEX = 0;  
RED\_INDEX = 1;  
GREEN\_INDEX = 2;  
BLUE\_INDEX = 3;  
WHITE\_INDEX = 4;  
clut(BLACK\_INDEX + 1, :) = [0 0 0];   
clut(RED\_INDEX + 1, :) = [255 0 0];  
clut(GREEN\_INDEX + 1, :) = [0 255 0];  
clut(BLUE\_INDEX + 1, :) = [0 0 255];  
clut(WHITE\_INDEX + 1, :) = [255 255 255];  
  
res=nearestresolution(0,1024,768,85,8); %the res. doesn't affect problem  
[wp, rect] = SCREEN(0, 'OpenWindow', Bkcolor,[0 0 p.w p.h],res);  
SCREEN(wp, 'SetClut', clut); % Set the CLUT (color look-up table)  
  
% now draw text to screen and clear text after key is pressed  
center = [rect(3) rect(4)]/2; % center of screen (pixel coordinates)  
txt = 'PRESS ANY KEY TO BEGIN';  
txtloc = [center(1) - length(txt) \* 7 / 2, center(2) + 40];  
[newX newY] = SCREEN(wp,'DrawText',txt,txtloc(1),txtloc(2),BLACK\_INDEX);  
kbwait;  
keyIsDown = 1;  
while(keyIsDown)  
 [keyIsDown,secs,keyCode] = KbCheck;  
end  
[newX newY] = SCREEN(wp,'DrawText',txt,txtloc(1),txtloc(2),Bkcolor);  
kbwait;  
SCREEN(wp,'Close');  
-----  
  
The result of this program? The text draws to the screen in red, but it  
is broken and almost unintelligible. If we draw the text to the screen  
using BLUE\_INDEX instead of RED\_INDEX, the parts of the text that were red  
now appear blue, but the parts of the letters that were not drawn in red  
before (they were black or missing) are now drawn in red or green. If the  
text is drawn with GREEN\_INDEX, the main parts of the letters are green,  
and the fragments are red. If the text is drawn with WHITE\_INDEX, the  
main part of the text is drawn in white, but the fragmented parts are  
mixed between red, blue and green.  
  
In each case, the text is properly erased with the second call to DrawText  
(using BLACK\_INDEX), though this isn't necessarily the case in another  
similar program I'm using.  
  
Does anyone know what is going on?  
  
Thanks for any help. The screentest report from the problem computer  
follows.  
  
keith  
-----  
  
\*\*\*\*\*\* daphne's PowerMac G3 Series/400, Mac OS 8.6 \*\*\*\*\*\*  
PsychToolbox 2.42, 7 March 2000, MATLAB 5.2.1.1421  
QuickTime 4.1  
FileSharing is on.  
Screen saver present, now disabled.  
Using UpTime-based timing, which is very accurate and reliable.  
G3, 400 MHz, memory bus 100 MHz, 49.966 Mflop/s  
\*\*\* Screen 0 \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*  
ATY,Rage128y (.Display\_Rage128 version 1.0f26) in slot J12  
8 bit dacs. 1024x768 85 Hz. (56,60,65,67,70,72,75,85,90,100,120 Hz avail)  
NOTE: DipPriorityAfterSetClut is true. Works around Rage128 driver bug.  
NOTE: MinimumSetClutPriority is 2. Works around Rage128 driver bug.  
pixel size 8 16 32 bits  
pages 1 1 1  
CopyWindow (ie CopyBits) 64 65 64 MB/s  
GetClut equals SetClut? == na na   
SetClutDriverWaitsForBlanking? Yes  
At priority 7 ... No blanking intrpts.  
SetClut (cscSetEntries) min dur. 0.1 0.1 0.1 frames  
At priority 1 ... Blanking interrupts.  
SetClut (cscSetEntries) min dur. 0.1 0.1 0.1 frames  
SetClut suppresses ints. for 0.0 0.0 0.0 frames  
\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*