[SOLVED] Painting Tshape using High CPU
lazarus / 39-Graphics

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Josh · 2023-05-08 22:34

Hi

probably something i am doing wrong.

i have a tshape on a form and am drawing a grid on it in the onpaint
event.

But when it fires, the cpu usage goes through the roof.

project attached.

if the grid is not displayed then stretch or shrink to envoke the
event, its as though it is continually being fired

event code
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.Shape1Paint(Sender: TObject);const hm=30;var i:integer;   
x1:Double;begin  if not runcode then exit;  with sender as tshape do 
begin    pen.Width:=4;    pen.Color:=clwhite;    pen.Style:=pssolid; 
 canvas.MoveTo(0,height div 2);    canvas.Line(0,height div 2,width,
height div 2);    x1:=width/hm;    pen.Width:=1;   
pen.Color:=clGray;    pen.Style:=psDot;    for i:=0 to hm do
canvas.Line(round(x1*i),0,round(x1*i),height);  end;end;             
   
forgot
Lazarus 2.2.7 (rev lazarus_2_2_6-1-gada7a90f86) FPC 3.2.3
x86_64-win64-win32/win64

note the pen.width does not appear toobeyed either

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Josh · 2023-05-08 22:44

ok fixed it.my stupidity 

i was not accessing the canvas pen color etc,of the form not the
tshape, which caused a repaint of the tshape.

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i begin  if
not runcode then exit;  with sender as tshape do  begin   
canvas.pen.Width:=4;    canvas.pen.Color:=clwhite;   
canvas.pen.Style:=pssolid;    canvas.MoveTo(0,height div 2);   
canvas.Line(0,height div 2,width, height div 2);    x1:=width/hm;   
canvas.pen.Width:=1;    canvas.pen.Color:=clGray;   
canvas.pen.Style:=psDot;    for i:=0 to hm do
canvas.Line(round(x1*i),0,round(x1*i),height);  end;end;