Draw distinction between bilinear filtering and nearest neighbour

assets/voxygen/shaders/antialias/bilinear.glsl

@@ -0,0 +1,8 @@
+vec4 aa_apply(
+    texture2D tex, sampler smplr,
+    texture2D depth_tex, sampler depth_smplr,
+    vec2 fragCoord,
+    vec2 resolution
+) {
+    return texture(sampler2D(tex, smplr), fragCoord / resolution);
+}

assets/voxygen/shaders/antialias/none.glsl

@@ -4,5 +4,5 @@ vec4 aa_apply(
     vec2 fragCoord,
     vec2 resolution
 ) {
-    return texture(sampler2D(tex, smplr), fragCoord / resolution);
+    return texelFetch(sampler2D(tex, smplr), ivec2(fragCoord * textureSize(sampler2D(tex, smplr), 0).xy / resolution), 0);
 }

voxygen/src/hud/settings_window/video.rs

@@ -879,6 +879,7 @@ impl<'a> Widget for Video<'a> {
         // interaction with greedy meshing, and may eventually be removed.
         let mode_list = [
             AaMode::None,
+            AaMode::Bilinear,
             AaMode::Fxaa,
             /* AaMode::MsaaX4,
             AaMode::MsaaX8,
@@ -887,7 +888,8 @@ impl<'a> Widget for Video<'a> {
             AaMode::Hqx,
         ];
         let mode_label_list = [
-            "No anti-aliasing",
+            "None",
+            "Bilinear",
             "FXAA",
             /* "MSAA x4",
             "MSAA x8",

voxygen/src/render/mod.rs

@@ -108,6 +108,15 @@ pub enum AaMode {
     /// Screen-space technique that uses a combination of FXAA and
     /// nearest-neighbour sample retargeting to produce crisp, clean upscaling.
     FxUpscale,
+    /// Bilinear filtering.
+    ///
+    /// Linear interpolation of the color buffer in each axis to determine the
+    /// pixel.
+    Bilinear,
+    /// Nearest-neighbour filtering.
+    ///
+    /// The colour of each pixel is determined by the colour of the spatially
+    /// closest texel in the color buffer.
     #[serde(other)]
     None,
 }
@@ -115,7 +124,7 @@ pub enum AaMode {
 impl AaMode {
     pub fn samples(&self) -> u32 {
         match self {
-            AaMode::None | AaMode::Fxaa | AaMode::Hqx | AaMode::FxUpscale => 1,
+            AaMode::None | AaMode::Bilinear | AaMode::Fxaa | AaMode::Hqx | AaMode::FxUpscale => 1,
             AaMode::MsaaX4 => 4,
             AaMode::MsaaX8 => 8,
             AaMode::MsaaX16 => 16,

voxygen/src/render/renderer/pipeline_creation.rs

@@ -258,6 +258,7 @@ impl ShaderModules {
         let anti_alias = shaders
             .get(match pipeline_modes.aa {
                 AaMode::None => "antialias.none",
+                AaMode::Bilinear => "antialias.bilinear",
                 AaMode::Fxaa => "antialias.fxaa",
                 AaMode::MsaaX4 => "antialias.msaa-x4",
                 AaMode::MsaaX8 => "antialias.msaa-x8",

voxygen/src/render/renderer/shaders.rs

@@ -38,6 +38,7 @@ impl assets::Compound for Shaders {
             "include.point_glow",
             "include.fxaa",
             "antialias.none",
+            "antialias.bilinear",
             "antialias.fxaa",
             "antialias.msaa-x4",
             "antialias.msaa-x8",