Practicing the fundamentals of computer graphics by building a 2D/3D graphic engine. Emphasis has been placed on simplicing and code-reuse, rather than preformance. The finished results are outputted as PPM files.

Code is based on the text 'BASIC CONCEPTS FOR COMPUTER GRAPHICS' by Dr. Amos Johnson. All credits go to Dr.Johnson, but all code remains under GPLv3. Enjoy!

Contains the bare essentials for the engine to run. These include:

• Color (class) - Object to contain RGB color info for pixels. Might use a 3 item tuple instead.
• Shape (class) - Base class for all geometric primitives.
• Image (class) - Object that contains all the pixel data for an image.

"Contains" all the geometric primitives for the 2D part of the engine. All the geometric primitives are based on the abtract class Shape. Included geometric primitives, and their constructors:

• Line(x1, x2, y1, y2)
• Ellipse(x1, y1, x2, y2, color)
• Circle(x, y, radius, color)
• Polygon(point_list, color)

Base class for all geometric primitives. If you are going to understand how this works you will need to read this first.

• __init__ - Initializes vars.
• __str__ (return String) - Prints out all draw points for the shape. Primarily for debugging.

• border_color (type color Class) - Contains the RGB draw color for the shape's border.
• inside_color (type color Class) - Contains the RGB draw color for the shape's inside (or fill).
• border (type 2-tuples List) - Contains all the draw points for the shape's border.
• inside (type 2-tuples List) - Contains all the draw points for the shape's inside (or fill).

• draw() - Calculates all draw points for the shape, and stores in class data.
• draw_border() - Calculates a shape's border points. Implemented by child class.
• draw_inside() - Calculates a shapes's inside points (or fill). Implemented by child class.
• fill(color) - Fills the shape with a color. If no color is passed, then the border color will be used.
• remove_duplicates () - Removes all duplicate points for a passed list.

• move(x, y) - Translates a shape. Should be used instead of translate to avoid redrawing.
• translate(x, y) - Translates a shape.
• rotate(x, y, angle) - Rotates a shape.
• scale(x, y, factor_x, factor_y) - Scales a shape.

Contains all pixel data for in image.

• __init__ - Initializes vars. Fills background with white.

• x (type int) - X size of image.
• y (type int) - Y size of image.
• inten (type int) - Intensity of pixels. (Default is 255).
• img - Array of pixels.

• fill(color) - Fill the image with a passed background color. Default white.
• getIndex(x,y) - Get pixel index from (x,y).
• blit(shapeObj) - Draw a shape onto the image.
• save(path) - Saves a PPM file to the specified path.

Assuming the proper classes have been imported.

# Imports
import Class.GeoPrimitives

# Create a Blank Image
img = Image(320, 240)
# Fill Image with Color
img.fill( Color(245, 245, 245) )
# Create Line Objects
line1 = Line( 60, 120, 160, 120, Color(255, 0, 0) )
line2 = Line( 160, 120, 160, 220, Color(0, 255, 0) )
# Rotate Lines
line1.rotate( 160, 120, 45 )
line2.rotate( 160, 120, 45 )
# Scale Lines
line1.scale( 160, 120, .5, .5 )
line2.scale( 160, 120, .5, .5 )
# Translate Lines
line1.translate( 50, 50 )
line2.translate( 50, 50 )
# Draw Lines on Image
img.blit( line1 )
img.blit( line2 )
# Create/Write Image
img.save('test.ppm')

Output:

# Create Blank Image
img = Image(320, 240)
# Fill Image with Color
img.fill( Color(245, 245, 245) )
# Create Polygon
point_list = [ (60,120), (110, 200), (110, 150), (200, 220), (160, 120) ]
polygon1 = Polygon( point_list, Color(255,0,0) )
# Translate Polygon
polygon1.translate( 30, -30 )
# Scale Polygon
polygon1.scale( 160, 120, 1.5, 1.5 )
# Rotate Polygon
polygon1.rotate( 160, 120, -40 )
# Blit and Create/Write Image
img.blit( polygon1.fill() )
img.save('test.ppm')

Output: