Casio Python with fx-CG 50: Drawing Shapes with Casioplot (draws.py)
The Casio file draws.py is a file that use both the casioplot and math modules and contains four drawing functions.
The plot functions uses the pixel system.
Upper left hand corner: (0, 0) |
Upper right hand corner: (383, 0) |
Lower left hand corner: (0, 191) |
Lower right hand corner: (383, 191) |
The x axis increases going right and the y axis increases going down. This orientation is common for a pixel-orientated coordinate system.
Note that the pixels must be integers. A non-integer value for a pixel will cause an error.
Importing the draws module
After copying the file draws.py to your calculator, type: from draws import *
The casioplot and math modules will also be imported because the draws module is imported. This is the case of the fx-CG 50, and I’m pretty sure it will work with the other Casio calculators with Python (fx-9750GIII, fx-9860GIII, fx-CG 100, Graph Math+).
To clear the drawing screen, use the casioplot’s command clear_screen().
To show the picture, use the casioplot’s command show_screen().
The functions from the draws must be manually typed, as they will not appear in the catalog or VARS menu.
sline(x,sx,y,sy,l,c)
Draws a line from (x,y) of length l and color c. The color is a three-element tuple in the RGB format ((red, green, blue)).
The arguments sx and sy are direction/slope arguments which dictate the direction of the line.
To draw a line going left (←) |
Set sx = -1 and sy = 0 |
To draw a line going right (→) |
Set sx = 1 and sy = 0 |
To draw a line going up (↑) |
Set sx = 0 and sy = -1 |
To draw a line going down (↓) |
Set sx = 0 and sy = 1 |
To draw a line going right and up (↗) |
Set sx = 1 and sy = -1 |
To draw a line going left and up (↖) |
Set sx = -1 and sy = -1 |
To draw a line going right and down (↘) |
Set sx = 1 and sy = 1 |
To draw a line going left and down (↙) |
Set sx = -1 and sy = 1 |
Examples:
sline(1,1,1,0,140,(255,0,0)) draws a red line starting from (1,1) going right with length of 140 pixels
sline(180,0,100,-1,50,(0,255,0)) draws a green line starting from (180,100) going up with length of 50 pixels
The sample file draw1.py is a demonstration of the sline command.
box(x,xl,y,yl,c)
The box function draws a box with the upper left hand corner (x,y) with color c, horizontal length (width) xl, and vertical length (height) yl. The box draws to the right and down. The box is filled with the specified color. If xl = yl, the function will draw a square.
Example:
box(20,100,40,150,(128,128,128)) draws a gray rectangle with upper-left corner at (20,40) with horizontal length of100 and vertical length of 150.
box(300,60,0,60,(0,0,0)) draws a black square with upper-left corner at (300, 0) with the side length of 60.
The sample file draw2.py uses the box function to generate a random game map of land (green) and water (blue).
tri(x,xd,y,yd,l,c)
The tri function draws a 45-45-90 right triangle. The point (x,y) is the corner point that contains the right angle of 90°. The arguments xd and yd dictate the direction of the triangle (see table below).
The triangle is filled with color c. The sides of the triangle will be drawn with length l.
Example:
tri(80,1,80,-1,75,(0,128,128)) draws a teal 45-45-90 right triangle with the right angle located at (80, 80). The length is 75 pixels.
The sample file draw3.py uses the tri function to draw four triangles, one with each proper orientation.
circ(x,y,r,c)
The circ function draws a circle centered at (x, y) with radius r and color c. The circle is drawn as outline and not filled. To make the circle appear as smooth as possible, 720 points are plotted.
Example:
circ(190,100,85,(255,128,0)) draws an orange circle with radius 85, centered at (190, 100).
The file draw4.py demonstrates the circ function.
Casio fx-CG 50 Python: draws.py code
# drawing utilities
# 12-04-2024
from casioplot import *
from math import *
def sline(x,sx,y,sy,l,c):
for i in range(l+1):
set_pixel(x+sx*i,y+sy*i,c)
# upper left corner
def box(x,xl,y,yl,c):
for i in range(xl+1):
for j in range(yl+1):
set_pixel(x+i,y+j,c)
# right triangle
# (x,y) point with right angle
# l=length
# xd=1 right, xd=-1 left
# yd=1 down, yd=-1 up
def tri(x,xd,y,yd,l,c):
for i in range(l+1):
k=l-i
for j in range(k+1):
set_pixel(x+xd*i,y+yd*j,c)
# hallow circle
def circ(x,y,r,c):
for i in range(721):
t=2*pi*i/720
xr=int(x+r*cos(t))
yr=int(y+r*sin(t))
set_pixel(xr,yr,c)
You can download the draws.py and the example Python files here:
https://drive.google.com/file/d/1rGQHa60V7ZCE9Vs0kYy0cfIe0pOXqVaZ/view?usp=sharing
I hope you enjoy this program as much as I have making it,
Eddie
All original content copyright, © 2011-2025. Edward Shore. Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited. This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.
