Zenith and Nadir colors now provided as uniform input to fragment shader

amethyst_renderer/src/lib.rs

@@ -108,7 +108,7 @@ pub use {
     mtl::{Material, MaterialDefaults, MaterialTextureSet, TextureOffset},
     pass::{
         get_camera, set_vertex_args, DebugLinesParams, DrawDebugLines, DrawFlat, DrawFlatSeparate,
-        DrawPbm, DrawPbmSeparate, DrawShaded, DrawShadedSeparate, DrawSprite, DrawSkybox
+        DrawPbm, DrawPbmSeparate, DrawShaded, DrawShadedSeparate, DrawSprite, DrawSkybox, SkyboxColor
     },
     pipe::{
         ColorBuffer, Data, DepthBuffer, DepthMode, Effect, EffectBuilder, Init, Meta, NewEffect,

amethyst_renderer/src/pass/shaders/fragment/skybox.glsl

@@ -10,10 +10,11 @@ in VertexData {
 
 out vec4 out_color;
 
-vec3 zenith_color = vec3(0.75, 1.0, 1.0);
-vec3 nadir_color = vec3(0.2, 0.4, 0.45);
+uniform vec3 zenith_color;
+uniform vec3 nadir_color;
 
 void main() {
-    vec3 horizon_color = mix(nadir_color, zenith_color, smoothstep(-1., 1., vertex.position.y));
+    vec3 normalized_position = normalize(vertex.position.xyz);
+    vec3 horizon_color = mix(nadir_color, zenith_color, smoothstep(-1., 1., normalized_position.y));
     out_color = vec4(horizon_color, 1.0f);
 }

amethyst_renderer/src/pass/skybox/interleaved.rs

@@ -20,7 +20,7 @@ use gfx::pso::buffer::ElemStride;
 use glsl_layout::{mat4, Uniform};
 use std::marker::PhantomData;
 
-use super::{VERT_SRC, FRAG_SRC};
+use super::{VERT_SRC, FRAG_SRC, SkyboxColor};
 
 #[repr(C, align(16))]
 #[derive(Clone, Copy, Debug, Uniform)]
@@ -62,6 +62,7 @@ where
         Option<Read<'a, ActiveCamera>>,
         ReadStorage<'a, Camera>,
         ReadStorage<'a, GlobalTransform>,
+        Read<'a, SkyboxColor>,
     );
 }
 
@@ -85,6 +86,8 @@ where
                 PosNormTex::ATTRIBUTES, PosNormTex::size() as ElemStride, 0
             )
             .with_raw_global("camera_position")
+            .with_raw_global("zenith_color")
+            .with_raw_global("nadir_color")
             .with_output("color", Some(DepthMode::LessEqualWrite))
             .build()
     }
@@ -94,7 +97,7 @@ where
         encoder: &mut Encoder,
         effect: &mut Effect,
         mut _factory: Factory,
-        (active, camera, global): <Self as PassData<'a>>::Data,
+        (active, camera, global, skybox_color): <Self as PassData<'a>>::Data,
     ) {
         let camera = get_camera(active, &camera, &global);
 
@@ -110,6 +113,8 @@ where
             return;
         }
 
+        effect.update_global("zenith_color", Into::<[f32; 3]>::into(skybox_color.zenith));
+        effect.update_global("nadir_color", Into::<[f32; 3]>::into(skybox_color.nadir));
         effect.draw(mesh.slice(), encoder);
         effect.clear();
     }

amethyst_renderer/src/pass/skybox/mod.rs

@@ -1,6 +1,23 @@
 pub use self::interleaved::DrawSkybox;
 
+use color::Rgba;
+
 mod interleaved;
 
 static VERT_SRC: &[u8] = include_bytes!("../shaders/vertex/skybox.glsl");
 static FRAG_SRC: &[u8] = include_bytes!("../shaders/fragment/skybox.glsl");
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct SkyboxColor {
+    pub zenith: Rgba,
+    pub nadir: Rgba,
+}
+
+impl Default for SkyboxColor {
+    fn default() -> SkyboxColor {
+        SkyboxColor {
+            zenith: Rgba(0.75, 1.0, 1.0, 1.0),
+            nadir: Rgba(0.1, 0.3, 0.35, 1.0),
+        }
+    }
+}