From ebb55da52cb79e40eed09aefe92af3e6c32bf00a Mon Sep 17 00:00:00 2001
From: Thomas Forgione <thomas@forgione.fr>
Date: Thu, 3 Oct 2019 16:25:28 +0200
Subject: [PATCH] Nice

---
 assets/shaders/default.frag | 50 ++++++++++++++++++++++++++++++++++---
 assets/shaders/default.vert |  5 ++++
 src/model/mod.rs            | 35 ++++++++++++++++++--------
 src/programs/viewer.rs      |  1 +
 4 files changed, 78 insertions(+), 13 deletions(-)

diff --git a/assets/shaders/default.frag b/assets/shaders/default.frag
index bdebc2f..ea753e5 100644
--- a/assets/shaders/default.frag
+++ b/assets/shaders/default.frag
@@ -1,31 +1,75 @@
 #version 140
 
+#extension GL_OES_standard_derivatives : enable
+
+
 uniform sampler2D tex;
 uniform vec3 diffuse;
 
 in vec3 v_normal;
 in vec2 v_tex_coords;
+in vec3 v_barycentric;
+in vec4 v_position;
 
 out vec4 color;
 
+vec4 wireframe_color;
+vec4 render_color;
+
 vec3 ambientLight = vec3(0.3,0.3,0.3);
 vec3 directionnalLight = normalize(vec3(10,5,7));
 vec3 directionnalLightFactor = vec3(0.6,0.6,0.6);
 
+// float edgeFactor(vec3 a){
+//     vec3 d = fwidth(v_barycentric);
+//     vec3 a3 = smoothstep(vec3(0.0), d*1.5, v_barycentric);
+//     return min(min(a3.x, a3.y), a3.z);
+// }
+
 void main() {
 
+
+    vec3 d = fwidth(v_barycentric);
+    vec3 a3 = smoothstep(vec3(0.0), 0.8 * d, v_barycentric);
+    float scale = (1 - min(min(a3.x, a3.y), a3.z)) / 2 + 0.5;
+
+    wireframe_color = vec4(scale, scale, scale, 1.0);
+
+    // float threshold = 0.1;
+    // vec3 d = fwidth(v_barycentric);
+
+    // if (d.x < threshold || d.y < threshold || d.z < threshold) {
+    //     wireframe_color = vec4(1.0, 1.0, 1.0, 1.0);
+    // } else {
+    //     wireframe_color = vec4(0.5, 0.5, 0.5, 1.0);
+    // }
+
     vec3 lambertComponent = dot(directionnalLight, v_normal) * directionnalLightFactor;
     lambertComponent = max(vec3(0.0, 0.0, 0.0), lambertComponent);
 
     vec4 factor = vec4(ambientLight + lambertComponent, 1.0);
 
-    color = factor * vec4(diffuse, 1.0) * texture(tex, v_tex_coords);
+    render_color = factor * vec4(diffuse, 1.0) * texture(tex, v_tex_coords);
 
-    if (color.a < 0.05) {
+    if (render_color.a < 0.05) {
         discard;
     } else {
-        color.a = 1.0;
+        render_color.a = 1.0;
     }
 
+    float z_min = 0.15;
+    float z_max = 0.25;
+
+    float lambda = (v_position.z - z_min) / (z_max - z_min);
+
+    if (lambda < 0) {
+        lambda = 0;
+    }
+    if (lambda > 1) {
+        lambda = 1;
+    }
+
+    color = lambda * wireframe_color + (1 - lambda) * render_color;
+
 }
 
diff --git a/assets/shaders/default.vert b/assets/shaders/default.vert
index b4bfb74..33e5efe 100644
--- a/assets/shaders/default.vert
+++ b/assets/shaders/default.vert
@@ -6,14 +6,19 @@ uniform vec3 texture_size;
 
 in vec3 vertex;
 in vec2 tex_coords;
+in vec3 barycentric;
 in vec3 normal;
 
 out vec2 v_tex_coords;
 out vec3 v_normal;
+out vec3 v_barycentric;
+out vec4 v_position;
 
 void main() {
     v_normal = normal;
+    v_barycentric = barycentric;
     v_tex_coords = vec2(tex_coords.x * texture_size.x, tex_coords.y * texture_size.y);
 
     gl_Position = perspective * view * vec4(vertex, 1.0);
+    v_position = gl_Position;
 }
diff --git a/src/model/mod.rs b/src/model/mod.rs
index 15aafa4..5b4f1bb 100644
--- a/src/model/mod.rs
+++ b/src/model/mod.rs
@@ -23,13 +23,14 @@ use renderer::Renderer;
 #[derive(Copy, Clone, Debug, PartialEq)]
 /// A raw vertex, with its 3D coordinates, texture coordinates and normals.
 pub struct Vertex {
-    vertex:     [f64; 3],
-    tex_coords: [f64; 2],
-    normal:     [f64; 3],
-    face_color: [f64; 3],
+    vertex:      [f64; 3],
+    tex_coords:  [f64; 2],
+    normal:      [f64; 3],
+    barycentric: [f64; 3],
+    face_color:  [f64; 3],
 }
 
-implement_vertex!(Vertex, vertex, tex_coords, normal, face_color);
+implement_vertex!(Vertex, vertex, tex_coords, normal, barycentric, face_color);
 
 /// A part of a 3D model.
 ///
@@ -534,7 +535,12 @@ impl Model {
 
         let mut vertex_buffer = vec![];
         for face in part.faces() {
-            for &&v in &[&face.a, &face.b, &face.c] {
+            let v0 = vertices[face.a.vertex];
+            let v1 = vertices[face.b.vertex];
+            let v2 = vertices[face.c.vertex];
+            let barycenter = (v0 + v1 + v2) / 3.0;
+
+            for (index, &&v) in [&face.a, &face.b, &face.c].iter().enumerate() {
                 let vertex = vertices[v.vertex].into();
                 let tex_coord = if let Some(tex_index) = v.texture_coordinate {
                     texture_coordinates[tex_index].into()
@@ -542,6 +548,14 @@ impl Model {
                     [0.0, 0.0]
                 };
 
+
+                let barycentric = match index {
+                    0 => [1.0, 0.0, 0.0],
+                    1 => [0.0, 1.0, 0.0],
+                    2 => [0.0, 0.0, 1.0],
+                    _ => unreachable!(),
+                };
+
                 let normal = if let Some(normal_index) = v.normal {
                     normals[normal_index].into()
                 } else {
@@ -564,10 +578,11 @@ impl Model {
                 ];
 
                 vertex_buffer.push(Vertex {
-                    vertex:     vertex,
-                    tex_coords: tex_coord,
-                    normal:     normal,
-                    face_color: [r, g, b],
+                    vertex:      vertex,
+                    tex_coords:  tex_coord,
+                    normal:      normal,
+                    barycentric: barycentric,
+                    face_color:  [r, g, b],
                 });
             }
         }
diff --git a/src/programs/viewer.rs b/src/programs/viewer.rs
index 389075f..aad928e 100644
--- a/src/programs/viewer.rs
+++ b/src/programs/viewer.rs
@@ -131,6 +131,7 @@ fn main() {
     let context = glutin::ContextBuilder::new().with_depth_buffer(24);
     let display = Display::new(window, context, &events_loop).unwrap();
     let mut renderer = Renderer::new(display);
+    renderer.set_clear_color(1.0, 1.0, 1.0, 1.0);
 
     let mut scene = Scene::new();
     let mut before;