agg 0.1.0

High-quality 2D graphics engine based on Anti-grain Geometry
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150


extern crate agg;

use agg::PixelData;
use agg::Render;
use agg::VertexSource;
//use std::fs;
use std::path::PathBuf;
use std::path::Path;
use std::env;

fn ppm_names() -> (PathBuf,PathBuf) {
    let progname = env::args().next().unwrap();
    let progname = Path::new(&progname);
    let mut base = progname.file_stem().unwrap().to_string_lossy().into_owned();
    let n = base.rfind("-").unwrap();
    base.truncate(n);
    let ppm = Path::new(&base).with_extension("ppm");
    let test = Path::new("tests").join(ppm.clone());
    (ppm, test)
}

pub struct Roundoff<T: VertexSource> {
    pub src: T,
}

impl<T> Roundoff<T> where T: VertexSource {
    fn new(src: T) -> Self {
        Self { src }
    }
}

impl<T> VertexSource for Roundoff<T> where T: VertexSource {
    fn xconvert(&self) -> Vec<agg::Vertex<f64>> {
        self.src.xconvert()
            .into_iter()
            .map(|v| agg::Vertex::new(v.x.floor(), v.y.floor(), v.cmd) )
            .collect()
    }
}

#[derive(Debug,Default)]
pub struct Spiral {
    x: f64,
    y: f64,
    r1: f64,
    r2: f64,
    step: f64,
    start_angle: f64,
    da: f64,
    dr: f64,
}

impl VertexSource for Spiral {
    fn xconvert(&self) -> Vec<agg::Vertex<f64>> {
        self.spin_spin_spin()
    }
}

impl Spiral {
    pub fn new(x: f64, y: f64, r1: f64, r2: f64, step: f64, start_angle: f64) -> Self {
        let da = 8.0f64.to_radians();
        let dr = step / 45.0;
        Self {x, y, r1, r2, step, start_angle, da, dr}
    }
    pub fn spin_spin_spin(&self) -> Vec<agg::Vertex<f64>> {
        let mut out = vec![];
        //let mut i = 0;
        let mut r = self.r1;
        let mut angle = self.start_angle;
        while r <= self.r2 {
            let x = self.x + angle.cos() * r;
            let y = self.y + angle.sin() * r;
            if out.is_empty() {
                out.push( agg::Vertex::move_to(x, y));
            } else {
                out.push( agg::Vertex::line_to(x, y));
            }
            //i += 1;
            r += self.dr;
            angle += self.da;
            //r = self.r1 + i as f64 * self.dr;
            //angle = self.start_angle + i as f64 * self.da;
        }
        out
    }
}

#[test]
fn rasterizers2() {
    let (w,h) = (500, 450);

    let pixf = agg::Pixfmt::<agg::Rgb8>::new(w, h);
    let mut ren_base = agg::RenderingBase::new(pixf);

    ren_base.clear( agg::Rgba8::new(255, 255, 242, 255) );

    let start_angle = 0.0;
    let line_width = 3.0;
    let _width  = w as f64;
    let height = h as f64;
    let (r1, r2) = (5.0, 70.0);
    let step = 16.0;
    // Anti-aliased Scanline Spiral
    {
        let x = (w / 2) as f64;
        let y = (h - h / 4 + 20) as f64;
        let spiral = Spiral::new(x, y, r1, r2, step, start_angle);

        let mut ras_aa = agg::RasterizerScanline::new();
        let mut ren_aa = agg::RenderingScanlineAASolid::with_base(&mut ren_base);
        let mut stroke = agg::ConvStroke::new(spiral);
        stroke.width(line_width);
        //stroke.cap(round_cap);
        ren_aa.color( &agg::Rgba8::new(102, 77, 26, 255));
        ras_aa.add_path(&stroke);
        agg::render_scanlines(&mut ras_aa, &mut ren_aa);

    }
    // Aliased Pixel Accuracy
    {
        let x = (w / 5) as f64;
        let y = (h / 4 + 50) as f64;
        let spiral = Spiral::new(x, y, r1, r2, step, start_angle);

        let mut ren_prim = agg::RendererPrimatives::with_base(&mut ren_base);
        ren_prim.line_color(agg::Rgba8::new(102, 77, 26, 255));
        let mut ras_al = agg::RasterizerOutline::with_primative(&mut ren_prim);
        let trans = Roundoff::new(spiral);
        ras_al.add_path(&trans);
    }
    // Aliased Subpixel Accuracy
    {
        let x = (w / 2) as f64;
        let y = (h / 4 + 50) as f64;
        eprintln!("DDA SPIRAL: {} {} h {} h/4 {}", x, y, height, height/4.0);
        let spiral = Spiral::new(x, y, r1, r2, step, start_angle);

        let mut ren_prim = agg::RendererPrimatives::with_base(&mut ren_base);
        ren_prim.line_color(agg::Rgba8::new(102, 77, 26, 255));
        let mut ras_al = agg::RasterizerOutline::with_primative(&mut ren_prim);
        ras_al.add_path(&spiral);
    }

    let (ppm, test) = ppm_names();

    agg::ppm::write_ppm(&ren_base.pixeldata(), w, h, ppm.clone()).unwrap();
    agg::ppm::compare_ppm(ppm, test);

}