`stroke()` does not handle float values correctly

stroke() appears to mis-handle float inputs. When using floats (e.g. 150.0), the rendered color is incorrect

Expected behavior

Float values in the same range as integers should produce identical results, as in Processing.

Actual behavior

• stroke(150) → correct grayscale
• stroke(150.0) → renders as white

Reproduction (mewnala)

from mewnala import *

def setup():
    size(640, 360)
    background(255)

def draw():
    stroke(150.0)
    line(0, 0, width, height)
    line(width, 0, 0, height)

    stroke(155.0, 100.0, 0.0)
    line(0, height // 2, width, height // 2)
    line(width // 2, 0, width // 2, height)

run()

Equivalent Processing sketch (works as expected)

void setup() {
  size(640, 360);
  background(255);
}

void draw() {
  stroke(150.0);
  line(0, 0, width, height);
  line(width, 0, 0, height);

  stroke(155.0, 100.0, 0.0);
  line(0, height/2, width, height/2);
  line(width/2, 0, width/2, height);
}

首先定位 stroke() 的 Rust 实现，并运行提供的 mewnala 复现。以 Processing sketch 作为预期参考，比较整数和浮点灰度输入及 RGB 输入的处理方式。当等效的浮点值和整数值渲染出相同颜色，并且在相关测试存在时包含相应的测试覆盖，即视为完成。