From 0275d01b96824d949b46fa1b60f040d04cc2e4dd Mon Sep 17 00:00:00 2001
From: Jared Roberts <jaredr@gmail.com>
Date: Thu, 6 Oct 2016 18:20:08 -0700
Subject: [PATCH] use texture array instead of atlas for tiles

---
 src/scenes/shader/tile_frag.glsl | 10 ++++++----
 src/scenes/world.rs              |  4 ++--
 src/tile.rs                      | 13 +++++++------
 3 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/src/scenes/shader/tile_frag.glsl b/src/scenes/shader/tile_frag.glsl
index 51b0f88..650fa52 100644
--- a/src/scenes/shader/tile_frag.glsl
+++ b/src/scenes/shader/tile_frag.glsl
@@ -1,9 +1,11 @@
 #version 150
 
+#define MILLIS_PER_TILE 4000u
+
 in vec2 v_uv;
 flat in uint v_tileidx;
 out vec4 pixcolor;
-uniform sampler2D t_atlas;
+uniform sampler2DArray t_tiles;
 uniform b_constants {
   uvec4 anim;
   float R1;
@@ -19,8 +21,8 @@ uniform b_locals {
 void main() {
   vec2 anim_uv = v_uv;
   if (v_tileidx < 128u && bool(anim[v_tileidx / 32u] & 1u << v_tileidx % 32u)) {
-    anim_uv = vec2(v_uv.x, float((uint(v_uv.y * 1000.0) + millis / 4u) % 1000u) / 1000.0);
+    anim_uv = vec2(v_uv.x, v_uv.y + float(millis % MILLIS_PER_TILE) / MILLIS_PER_TILE);
   }
-  vec2 uv = vec2(anim_uv.x, float(v_tileidx) / 256.0 + (1.0 - anim_uv.y) / 256.0);
-  pixcolor = texture(t_atlas, uv);
+
+  pixcolor = texture(t_tiles, vec3(anim_uv.x, 1.0 - anim_uv.y, v_tileidx));
 }
diff --git a/src/scenes/world.rs b/src/scenes/world.rs
index c76aabb..d059785 100644
--- a/src/scenes/world.rs
+++ b/src/scenes/world.rs
@@ -52,7 +52,7 @@ gfx_defines! {
     trans: gfx::ConstantBuffer<::view::Trans> = "b_trans",
     constants: gfx::ConstantBuffer<Constants> = "b_constants",
     locals: gfx::ConstantBuffer<Locals> = "b_locals",
-    atlas: gfx::TextureSampler<[f32; 4]> = "t_atlas",
+    atlas: gfx::TextureSampler<[f32; 4]> = "t_tiles",
     pixcolor: gfx::RenderTarget<::view::ColorFormat> = "pixcolor",
     depth: gfx::DepthTarget<::view::DepthFormat> = gfx::preset::depth::LESS_EQUAL_WRITE,
   }
@@ -157,7 +157,7 @@ impl<D: gfx::Device, F: gfx::Factory<D::Resources>> WorldScene<D, F> {
       locals: factory.create_constant_buffer(1),
       atlas: tile::get_tiles::<_, _, view::ColorFormat>(factory),
       sampler: factory.create_sampler(tex::SamplerInfo::new(tex::FilterMethod::Scale,
-                                                            tex::WrapMode::Clamp)),
+                                                            tex::WrapMode::Tile)),
       f: PhantomData,
 
       vbuf: vertex_buffer,
diff --git a/src/tile.rs b/src/tile.rs
index 3c4aa1c..882003c 100644
--- a/src/tile.rs
+++ b/src/tile.rs
@@ -22,12 +22,13 @@ pub fn get_tiles<R, F, T>(factory: &mut F) -> (//gfx::handle::Texture<R, T::Surf
   let filename = "data/SHAPES.EGA";
   let mut file = std::fs::File::open(Path::new(filename))
     .expect(&format!("failed opening tiles file: {}", filename));
-  let mut ega_vec = Vec::new();
-  file.read_to_end(&mut ega_vec).expect("Read tiles file");
-  let ega_page = ega::decode(&ega_vec, ega::Compression::UNCOMPRESSED, ega::Tiling::TILED(16));
-  let tex = factory.create_texture_const_u8::<T>(tex::Kind::D2(16, 16 * 256,
-                                                               tex::AaMode::Single),
-                                                 &[&ega_page.data])
+  let mut ega_bytes = Vec::new();
+  file.read_to_end(&mut ega_bytes).expect("Read tiles file");
+  let ega_page = ega::decode(&ega_bytes, ega::Compression::UNCOMPRESSED, ega::Tiling::TILED(16));
+  let tiles: Vec<&[u8]> = ega_page.iter().collect();
+  let tex = factory.create_texture_const_u8::<T>(tex::Kind::D2Array(16, 16, 256,
+                                                                    tex::AaMode::Single),
+                                                 &tiles)
                    .expect("create tile texture");
   tex.1
 }