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use PolarCoord type and define conversion functions

master
Wesley Kerfoot 3 years ago
parent
4bb0c8bd87
commit
7e31c0ba15
1 changed files with 65 additions and 19 deletions
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  1. 84
      src/lsystem.nim

84
src/lsystem.nim
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@ -35,15 +35,18 @@ proc rewrite(terms: Terms, maxIterations: int) : Terms =
for _ in repeat(0, maxIterations):
currentTerms = @[LineTerm] & currentTerms
return currentTerms
type PolarCoord = object
angle: float64
magnitude: float64
type StackControl = enum Push, Pop
# An intruction along with a change in angle and magnitude (i.e. a vector)
type DrawInstruction = object
angle_change: float64
width: float64
magnitude: float64
color: Color
coord: PolarCoord
type
InstructionKind = enum pkDraw, pkStack
@ -54,7 +57,7 @@ type
proc `$` (i: Instruction): string =
case i.kind:
of pkDraw: return "angle_change = " & $i.drawInstruction.angle_change & ", magnitude = " & $i.drawInstruction.magnitude
of pkDraw: return "angle_change = " & $i.drawInstruction.coord.angle & ", magnitude = " & $i.drawInstruction.coord.magnitude
of pkStack: return "direction = " & $i.stackInstruction
iterator axiomToInstructions(maxIterations: int, magnitude: float64, angle: float64, leafColor: Color = DARKGREEN) : Instruction =
@ -67,7 +70,7 @@ iterator axiomToInstructions(maxIterations: int, magnitude: float64, angle: floa
var current_magnitude = magnitude
var current_width: float64 = widths[0]
# axiom
yield Instruction(kind: pkDraw, drawInstruction: DrawInstruction(angle_change: 180, magnitude: magnitude))
yield Instruction(kind: pkDraw, drawInstruction: DrawInstruction(coord: PolarCoord(angle: 180, magnitude: magnitude)))
for term in termsToConvert:
# TODO make this definable by the grammar and/or tweakable
@ -81,12 +84,31 @@ iterator axiomToInstructions(maxIterations: int, magnitude: float64, angle: floa
# TODO make this definable by the grammar and/or tweakable
currentLeafColor.r += (sample(@[5, 2, 10, -1, -2, 3]).uint8)
yield Instruction(kind: pkDraw, drawInstruction: DrawInstruction(color: currentLeafColor, width: leaf_width, angle_change: angle_delta, magnitude: magnitudes[0]))
yield Instruction(kind: pkDraw, drawInstruction: DrawInstruction(color: currentLeafColor, width: leaf_width, angle_change: 0, magnitude: -magnitudes[0])) # hack
yield Instruction(kind: pkDraw, drawInstruction: DrawInstruction(color: currentLeafColor, width: leaf_width, angle_change: -(angle_delta*2), magnitude: magnitudes[0]))
yield Instruction(kind: pkDraw,
drawInstruction:
DrawInstruction(color: currentLeafColor,
width: leaf_width,
coord: PolarCoord(angle: angle_delta, magnitude: magnitudes[0])))
yield Instruction(kind: pkDraw,
drawInstruction:
DrawInstruction(color: currentLeafColor,
width: leaf_width,
coord: PolarCoord(angle: 0, magnitude: -magnitudes[0]))) # hack
yield Instruction(kind: pkDraw,
drawInstruction:
DrawInstruction(color: currentLeafColor,
width: leaf_width,
coord: PolarCoord(angle: -(angle_delta*2),
magnitude: magnitudes[0])))
of LineTerm:
# Draw without changing direction
yield Instruction(kind: pkDraw, drawInstruction: DrawInstruction(color: DARKBROWN, width: current_width, angle_change: 0, magnitude: magnitudes[0]))
yield Instruction(kind: pkDraw,
drawInstruction:
DrawInstruction(color: DARKBROWN,
width: current_width,
coord: PolarCoord(angle: 0, magnitude: magnitudes[0])))
# L-systems don't go "backwards"
# So you can go left or right on the x-axis at a given angle delta
@ -94,12 +116,23 @@ iterator axiomToInstructions(maxIterations: int, magnitude: float64, angle: floa
# TODO make this definable by the grammar and/or tweakable
current_magnitude = current_magnitude - (current_magnitude * sample(@[0.05, 0.10]))
current_width = current_width - (current_width * sample(@[0.15, 0.10]))
yield Instruction(kind: pkDraw, drawInstruction: DrawInstruction(color: DARKBROWN, width: current_width, angle_change: angle_delta, magnitude: current_magnitude))
yield Instruction(kind: pkDraw,
drawInstruction:
DrawInstruction(color: DARKBROWN,
width: current_width,
coord: PolarCoord(angle: angle_delta, magnitude: current_magnitude)))
of GoRight:
# TODO make this definable by the grammar and/or tweakable
current_magnitude = current_magnitude - (current_magnitude * sample(@[0.05, 0.01]))
current_width = current_width - (current_width * sample(@[0.15, 0.10]))
yield Instruction(kind: pkDraw, drawInstruction: DrawInstruction(color: DARKBROWN, width: current_width, angle_change: -angle_delta, magnitude: current_magnitude))
yield Instruction(kind: pkDraw,
drawInstruction:
DrawInstruction(color: DARKBROWN,
width: current_width,
coord: PolarCoord(angle: -angle_delta, magnitude: current_magnitude)))
# Control the stack of saved positions
of PushTerm:
@ -145,21 +178,32 @@ type DrawLine = object
proc `$` (d: DrawLine): string =
return "start_pos = " & $d.start_pos & ", " & "end_pos = " & $d.end_pos
proc calculateNextLine(inst: DrawInstruction, pos: StartingPosition) : DrawLine =
# Change the angle
let new_angle = inst.angle_change + pos.angle
proc polarToCartesian(coord: PolarCoord): Vector2 =
# Convert from polar coordinates to cartesian
# angle is in degrees
let new_x = -(coord.magnitude * cos(degToRad(coord.angle)))
let new_y = coord.magnitude * sin(degToRad(coord.angle))
# Use the same magnitude as before
let magnitude = inst.magnitude
return Vector2(x: new_x, y: new_y)
# Convert from polar coordinates to cartesian
let new_x = -(magnitude * cos(degToRad(new_angle)))
let new_y = magnitude * sin(degToRad(new_angle))
proc cartesianToPolar(start_pos: Vector2, end_pos: Vector2): PolarCoord =
# Convert from cartesian coordinates to polar
# angle is in degrees
let magnitude = sqrt((end_pos.y - start_pos.y)^2 + (end_pos.x - start_pos.x)^2)
let angle = radToDeg(arcsin(end_pos.y / magnitude))
return PolarCoord(magnitude: magnitude, angle: angle)
proc calculateNextLine(inst: DrawInstruction, pos: StartingPosition) : DrawLine =
# Change the angle
let new_angle = inst.coord.angle + pos.angle
let endPosition = polarToCartesian(PolarCoord(magnitude: inst.coord.magnitude, angle: new_angle))
result.start_pos = Vector2(x: pos.x, y: pos.y)
# Ending position is relative to the starting position, so add the coordinates
result.end_pos = Vector2(x: result.start_pos.x+new_x, y: result.start_pos.y+new_y)
result.end_pos = Vector2(x: result.start_pos.x+endPosition.x, y: result.start_pos.y+endPosition.y)
result.mid_pos = Vector2(x: result.start_pos.x, y: result.end_pos.y)
result.width = inst.width
@ -244,6 +288,8 @@ proc guiLoop*() =
var camera: Camera2D
#var testTexture = LoadTextureFromImage(LoadImage("./test_texture.png"))
camera.offset = Vector2(x: camera_x_offset, y: camera_y_offset)
camera.target = Vector2(x: screenWidth/2, y: screenHeight/2)

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