composite

2 files changed, 64 insertions, 2 deletions

diff --git a/src/main.rs b/src/main.rs
index 482e20a..d7b1349 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,7 +4,7 @@ use anyhow::Result;
 use blubcat::{
     color::Color,
     pattern::{Gradient, Rainbow, Sequence, Solid},
-    transform::{Matrix, Polar, Translate, Transpose},
+    transform::{Composite, CompositeOperation, Matrix, Polar, Translate, Transpose},
     Sample,
 };
 use std::{
@@ -139,6 +139,28 @@ fn main() -> Result<()> {
                     })
                 }
                 "-T" | "--transpose" => push_queue.push(box Transpose(pat.pop().unwrap())),
+
+                "--add" => push_queue.push(box Composite {
+                    a: pat.pop().unwrap(),
+                    b: pat.pop().unwrap(),
+                    mode: CompositeOperation::Add,
+                }),
+                "--subtract" => push_queue.push(box Composite {
+                    a: pat.pop().unwrap(),
+                    b: pat.pop().unwrap(),
+                    mode: CompositeOperation::Subtract,
+                }),
+                "--multiply" => push_queue.push(box Composite {
+                    a: pat.pop().unwrap(),
+                    b: pat.pop().unwrap(),
+                    mode: CompositeOperation::Multiply,
+                }),
+                "--mix" => push_queue.push(box Composite {
+                    a: pat.pop().unwrap(),
+                    b: pat.pop().unwrap(),
+                    mode: CompositeOperation::Mix(arg_num()),
+                }),
+
                 _ => panic!("unknown option {}", &a),
             }
             pat.extend(push_queue.drain(..))
@@ -167,7 +189,7 @@ fn main() -> Result<()> {
 
 fn flag_helper(colors: &[&str]) -> Box<dyn Sample> {
     box Matrix {
-        matrix: ((1.0 / 12.0, 1.0 / 12.0), (0.0, 0.0)),
+        matrix: ((1.0 / 6.0, 1.0 / 6.0), (0.0, 0.0)),
         inner: box Sequence(
             colors
                 .into_iter()
diff --git a/src/transform.rs b/src/transform.rs
index 0b65728..ccb1850 100644
--- a/src/transform.rs
+++ b/src/transform.rs
@@ -39,3 +39,43 @@ impl Sample for Translate {
         self.inner.sample(x - self.offset.0, y - self.offset.1)
     }
 }
+
+pub enum CompositeOperation {
+    Add,
+    Subtract,
+    Multiply,
+    Mix(f64),
+}
+pub struct Composite {
+    pub a: Box<dyn Sample>,
+    pub b: Box<dyn Sample>,
+    pub mode: CompositeOperation,
+}
+impl Sample for Composite {
+    fn sample(&mut self, x: f64, y: f64) -> Color {
+        let a = self.a.sample(x, y);
+        let b = self.b.sample(x, y);
+        match self.mode {
+            CompositeOperation::Add => Color {
+                r: a.r + b.r,
+                g: a.g + b.g,
+                b: a.b + b.b,
+            },
+            CompositeOperation::Subtract => Color {
+                r: a.r - b.r,
+                g: a.g - b.g,
+                b: a.b - b.b,
+            },
+            CompositeOperation::Multiply => Color {
+                r: a.r * b.r,
+                g: a.g * b.g,
+                b: a.b * b.b,
+            },
+            CompositeOperation::Mix(f) => Color {
+                r: a.r * (1.0 - f) + b.r * f,
+                g: a.g * (1.0 - f) + b.g * f,
+                b: a.b * (1.0 - f) + b.b * f,
+            },
+        }
+    }
+}