Auto merge of #1154 - tocubed:adjacency-info, r=kvark

Add primitives with adjacency information

Fixes #1152 by adding additional variants to `Primitive`.

Author: homu

src/backend/dx11/src/factory.rs

@@ -569,6 +569,10 @@ impl core::Factory<R> for Factory {
                 LineStrip       => D3D11_PRIMITIVE_TOPOLOGY_LINESTRIP,
                 TriangleList    => D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST,
                 TriangleStrip   => D3D11_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP,
+                LineListAdjacency        => D3D11_PRIMITIVE_TOPOLOGY_LINELIST_ADJ,
+                LineStripAdjacency       => D3D11_PRIMITIVE_TOPOLOGY_LINESTRIP_ADJ,
+                TriangleListAdjacency    => D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST_ADJ,
+                TriangleStripAdjacency   => D3D11_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP_ADJ,
                 PatchList(num)  => {
                     if num == 0 || (num as usize) > caps.max_patch_size {
                         return Err(core::pso::CreationError)

src/backend/gl/src/command.rs

@@ -29,6 +29,10 @@ fn primitive_to_gl(primitive: c::Primitive) -> gl::types::GLenum {
         LineStrip => gl::LINE_STRIP,
         TriangleList => gl::TRIANGLES,
         TriangleStrip => gl::TRIANGLE_STRIP,
+        LineListAdjacency => gl::LINES_ADJACENCY,
+        LineStripAdjacency => gl::LINE_STRIP_ADJACENCY,
+        TriangleListAdjacency => gl::TRIANGLES_ADJACENCY,
+        TriangleStripAdjacency => gl::TRIANGLE_STRIP_ADJACENCY,
         //TriangleFan => gl::TRIANGLE_FAN,
         PatchList(_) => gl::PATCHES
     }

src/backend/metal/src/map.rs

@@ -104,6 +104,13 @@ pub fn map_topology(primitive: Primitive) -> MTLPrimitiveTopologyClass {
         Primitive::LineStrip |
         Primitive::TriangleStrip |
         Primitive::PatchList(_) => MTLPrimitiveTopologyClass::Unspecified,
+
+        // Metal does not support geometry shaders and hence does not support
+        // adjacency primitives
+        Primitive::LineListAdjacency |
+        Primitive::LineStripAdjacency |
+        Primitive::TriangleListAdjacency |
+        Primitive::TriangleStripAdjacency => MTLPrimitiveTopologyClass::Unspecified,
     }
 }
 

src/backend/vulkan/src/data.rs

@@ -306,6 +306,10 @@ pub fn map_topology(prim: Primitive) -> vk::PrimitiveTopology {
         Primitive::LineStrip     => vk::PRIMITIVE_TOPOLOGY_LINE_STRIP,
         Primitive::TriangleList  => vk::PRIMITIVE_TOPOLOGY_TRIANGLE_LIST,
         Primitive::TriangleStrip => vk::PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP,
+        Primitive::LineListAdjacency      => vk::PRIMITIVE_TOPOLOGY_LINE_LIST_WITH_ADJACENCY,
+        Primitive::LineStripAdjacency     => vk::PRIMITIVE_TOPOLOGY_LINE_STRIP_WITH_ADJACENCY,
+        Primitive::TriangleListAdjacency  => vk::PRIMITIVE_TOPOLOGY_TRIANGLE_LIST_WITH_ADJACENCY,
+        Primitive::TriangleStripAdjacency => vk::PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP_WITH_ADJACENCY,
         Primitive::PatchList(_)  => vk::PRIMITIVE_TOPOLOGY_PATCH_LIST,
     }
 }

src/core/src/lib.rs

@@ -154,6 +154,26 @@ pub enum Primitive {
     /// Every three consecutive vertices represent a single triangle. For example, with `[a, b, c,
     /// d]`, `a`, `b`, and `c` form a triangle, and `b`, `c`, and `d` form a triangle.
     TriangleStrip,
+    /// Each quadtruplet of vertices represent a single line segment with adjacency information.
+    /// For example, with `[a, b, c, d]`, `b` and `c` form a line, and `a` and `d` are the adjacent
+    /// vertices.
+    LineListAdjacency,
+    /// Every four consecutive vertices represent a single line segment with adjacency information.
+    /// For example, with `[a, b, c, d, e]`, `[a, b, c, d]` form a line segment with adjacency, and
+    /// `[b, c, d, e]` form a line segment with adjacency.
+    LineStripAdjacency,
+    /// Each sextuplet of vertices represent a single traingle with adjacency information. For
+    /// example, with `[a, b, c, d, e, f]`, `a`, `c`, and `e` form a traingle, and `b`, `d`, and
+    /// `f` are the adjacent vertices, where `b` is adjacent to the edge formed by `a` and `c`, `d`
+    /// is adjacent to the edge `c` and `e`, and `f` is adjacent to the edge `e` and `a`.
+    TriangleListAdjacency,
+    /// Every even-numbered vertex (every other starting from the first) represents an additional
+    /// vertex for the triangle strip, while odd-numbered vertices (every other starting from the
+    /// second) represent adjacent vertices. For example, with `[a, b, c, d, e, f, g, h]`, `[a, c,
+    /// e, g]` form a triangle strip, and `[b, d, f, h]` are the adjacent vertices, where `b`, `d`,
+    /// and `f` are adjacent to the first triangle in the strip, and `d`, `f`, and `h` are adjacent
+    /// to the second.
+    TriangleStripAdjacency,
     /// Patch list,
     /// used with shaders capable of producing primitives on their own (tessellation)
     PatchList(PatchSize),

src/render/src/slice.rs

@@ -96,6 +96,10 @@ impl<R: Resources> Slice<R> {
             p::LineStrip => (nv-1),
             p::TriangleList => nv / 3,
             p::TriangleStrip => (nv-2) / 3,
+            p::LineListAdjacency => nv / 4,
+            p::LineStripAdjacency => (nv-3),
+            p::TriangleListAdjacency => nv / 6,
+            p::TriangleStripAdjacency => (nv-4) / 2,
             p::PatchList(num) => nv / (num as u32),
         }
     }