add support for brightness gradients

2 files changed, 70 insertions, 10 deletions

diff --git a/src/main.rs b/src/main.rs
index b241eb5..5de9d56 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -5,6 +5,7 @@ extern crate imageproc;
 extern crate itertools;
 extern crate md5;
 extern crate num_enum;
+extern crate num_traits;
 extern crate reqwest;
 extern crate rusttype;
 extern crate termcolor;
diff --git a/src/render.rs b/src/render.rs
index 437b66c..51f4ceb 100644
--- a/src/render.rs
+++ b/src/render.rs
@@ -1,7 +1,11 @@
 use super::api::{Api, ApiError, Skill, Specialization, Trait};
 use super::bt::{BuildTemplate, TraitChoice, Traitline};
-use image::{imageops, DynamicImage, GenericImage, GenericImageView, ImageBuffer, Rgba, RgbaImage};
+use image::{
+    imageops, CatmullRom, DynamicImage, GenericImage, GenericImageView, ImageBuffer, Pixel,
+    Primitive, Rgba, RgbaImage,
+};
 use imageproc::drawing::{self, Point};
+use num_traits::NumCast;
 use rusttype::{Font, Scale, SharedBytes};
 
 quick_error! {
@@ -24,6 +28,8 @@ pub struct RenderOptions {
     traitline_height: u32,
     traitline_width: u32,
     traitline_brightness: i32,
+    traitline_use_gradient: bool,
+    traitline_gradient_size: u32,
     traitline_x_offset: u32,
     trait_size: u32,
     line_color: Rgba<u8>,
@@ -43,6 +49,8 @@ impl Default for RenderOptions {
             traitline_height: 137,
             traitline_width: 647,
             traitline_brightness: 100,
+            traitline_use_gradient: true,
+            traitline_gradient_size: 50,
             traitline_x_offset: 200,
             trait_size: 30,
             line_color: Rgba([0, 0, 0, 255]),
@@ -78,11 +86,7 @@ impl<'r> Renderer<'r> {
     pub fn new(api: &mut Api, options: RenderOptions) -> Renderer<'_> {
         let minor_mask = image::load_from_memory(include_bytes!("minor_trait_mask.png"))
             .expect("Mask image could not be loaded")
-            .resize(
-                options.trait_size,
-                options.trait_size,
-                imageops::FilterType::CatmullRom,
-            );
+            .resize(options.trait_size, options.trait_size, CatmullRom);
         Renderer {
             api,
             options,
@@ -100,7 +104,7 @@ impl<'r> Renderer<'r> {
                 let img = self.api.get_image(&skill.icon)?.resize(
                     self.options.skill_size,
                     self.options.skill_size,
-                    imageops::FilterType::CatmullRom,
+                    CatmullRom,
                 );
                 buffer.copy_from(&img, i as u32 * self.options.skill_size, 0);
             }
@@ -116,7 +120,7 @@ impl<'r> Renderer<'r> {
         let minor_img = self.api.get_image(&minor.icon)?.resize(
             self.options.trait_size,
             self.options.trait_size,
-            imageops::FilterType::CatmullRom,
+            CatmullRom,
         );
         let minor_img = with_mask(&minor_img, &self.minor_mask);
         let y_pos = (buffer.height() - minor_img.height()) / 2;
@@ -138,7 +142,7 @@ impl<'r> Renderer<'r> {
         let major_img = self.api.get_image(&major.icon)?.resize(
             self.options.trait_size,
             self.options.trait_size,
-            imageops::FilterType::CatmullRom,
+            CatmullRom,
         );
         let major_img = if !chosen {
             with_mask(&major_img.grayscale(), &major_img)
@@ -225,7 +229,6 @@ impl<'r> Renderer<'r> {
                 BG_CROP_WIDTH,
                 BG_CROP_HEIGHT,
             )
-            .brighten(self.options.traitline_brightness)
             .resize(
                 self.options.traitline_width,
                 self.options.traitline_height,
@@ -233,6 +236,17 @@ impl<'r> Renderer<'r> {
             )
             .to_rgba();
 
+        if self.options.traitline_use_gradient {
+            buffer = brighten_gradient(
+                &buffer,
+                self.options.traitline_x_offset - self.options.traitline_gradient_size,
+                self.options.traitline_x_offset,
+                self.options.traitline_brightness,
+            );
+        } else {
+            buffer = imageops::colorops::brighten(&buffer, self.options.traitline_brightness);
+        }
+
         let minor_traits = self.api.get_traits(&spec.minor_traits)?;
         for minor in &minor_traits {
             self.render_minor_trait(&mut buffer, &minor)?;
@@ -337,3 +351,48 @@ where
         Rgba([p[0], p[1], p[2], alpha])
     })
 }
+
+fn brighten_gradient<I, P, S>(
+    image: &I,
+    start_x: u32,
+    end_x: u32,
+    value: i32,
+) -> ImageBuffer<P, Vec<S>>
+where
+    I: GenericImageView<Pixel = P>,
+    P: Pixel<Subpixel = S> + 'static,
+    S: Primitive + 'static,
+{
+    use image::math::utils::clamp;
+    let (width, height) = image.dimensions();
+    let mut out = ImageBuffer::new(width, height);
+
+    let max = S::max_value();
+    let max: i32 = NumCast::from(max).unwrap();
+
+    for y in 0..height {
+        for x in 0..width {
+            let e = image.get_pixel(x, y).map_with_alpha(
+                |b| {
+                    let interpol_value = if x < start_x {
+                        0
+                    } else if x > end_x {
+                        value
+                    } else {
+                        let frac = (x - start_x) as f32 / (end_x - start_x) as f32;
+                        (frac * value as f32).round() as i32
+                    };
+                    let c: i32 = NumCast::from(b).unwrap();
+                    let d = clamp(c + interpol_value, 0, max);
+
+                    NumCast::from(d).unwrap()
+                },
+                |alpha| alpha,
+            );
+
+            out.put_pixel(x, y, e);
+        }
+    }
+
+    out
+}