Update Tint samples to new entry point IO syntax

Change-Id: Iadfb311a66b709470740d13884e94702856858b4
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/46920
Auto-Submit: James Price <jrprice@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: James Price <jrprice@google.com>

test/compute_boids.wgsl

@@ -14,26 +14,23 @@
 
 // vertex shader
 
-[[location(0)]] var<in> a_particlePos : vec2<f32>;
-[[location(1)]] var<in> a_particleVel : vec2<f32>;
-[[location(2)]] var<in> a_pos : vec2<f32>;
-[[builtin(position)]] var<out> gl_Position : vec4<f32>;
-
 [[stage(vertex)]]
-fn vert_main() -> void {
+fn vert_main([[location(0)]] a_particlePos : vec2<f32>,
+             [[location(1)]] a_particleVel : vec2<f32>,
+             [[location(2)]] a_pos : vec2<f32>)
+          -> [[builtin(position)]] vec4<f32> {
   var angle : f32 = -atan2(a_particleVel.x, a_particleVel.y);
   var pos : vec2<f32> = vec2<f32>(
       (a_pos.x * cos(angle)) - (a_pos.y * sin(angle)),
       (a_pos.x * sin(angle)) + (a_pos.y * cos(angle)));
-  gl_Position = vec4<f32>(pos + a_particlePos, 0.0, 1.0);
+  return vec4<f32>(pos + a_particlePos, 0.0, 1.0);
 }
 
 // fragment shader
-[[location(0)]] var<out> fragColor : vec4<f32>;
 
 [[stage(fragment)]]
-fn frag_main() -> void {
-  fragColor = vec4<f32>(1.0, 1.0, 1.0, 1.0);
+fn frag_main() -> [[location(0)]] vec4<f32> {
+  return vec4<f32>(1.0, 1.0, 1.0, 1.0);
 }
 
 // compute shader
@@ -60,11 +57,10 @@ fn frag_main() -> void {
 [[binding(1), group(0)]] var<storage> particlesA : [[access(read_write)]] Particles;
 [[binding(2), group(0)]] var<storage> particlesB : [[access(read_write)]] Particles;
 
-[[builtin(global_invocation_id)]] var<in> gl_GlobalInvocationID : vec3<u32>;
-
 // https://github.com/austinEng/Project6-Vulkan-Flocking/blob/master/data/shaders/computeparticles/particle.comp
 [[stage(compute)]]
-fn comp_main() -> void {
+fn comp_main(
+  [[builtin(global_invocation_id)]] gl_GlobalInvocationID : vec3<u32>) -> void {
   var index : u32 = gl_GlobalInvocationID.x;
   if (index >= 5u) {
     return;

test/cube.wgsl

@@ -19,22 +19,28 @@
 
 [[binding(0), group(0)]] var<uniform> uniforms : [[access(read)]] Uniforms;
 
-[[location(0)]] var<in> cur_position : vec4<f32>;
-[[location(1)]] var<in> color : vec4<f32>;
-[[location(0)]] var<out> vtxFragColor : vec4<f32>;
-[[builtin(position)]] var<out> Position : vec4<f32>;
+struct VertexInput {
+  [[location(0)]] cur_position : vec4<f32>;
+  [[location(1)]] color : vec4<f32>;
+};
+
+struct VertexOutput {
+  [[location(0)]] vtxFragColor : vec4<f32>;
+  [[builtin(position)]] Position : vec4<f32>;
+};
 
 [[stage(vertex)]]
-fn vtx_main() -> void {
-   Position = uniforms.modelViewProjectionMatrix * cur_position;
-   vtxFragColor = color;
+fn vtx_main(input : VertexInput) -> VertexOutput {
+  var output : VertexOutput;
+  output.Position = uniforms.modelViewProjectionMatrix * input.cur_position;
+  output.vtxFragColor = input.color;
+  return output;
 }
 
 // Fragment shader
-[[location(0)]] var<in> fragColor : vec4<f32>;
-[[location(0)]] var<out> outColor : vec4<f32>;
 
 [[stage(fragment)]]
-fn frag_main() -> void {
-  outColor = fragColor;
+fn frag_main([[location(0)]] fragColor : vec4<f32>)
+          -> [[location(0)]] vec4<f32> {
+  return fragColor;
 }

test/simple.wgsl

@@ -12,14 +12,12 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-[[location(0)]] var<out> gl_FragColor : vec4<f32>;
-
 fn bar() -> void {
 }
 
 [[stage(fragment)]]
-fn main() -> void {
+fn main() -> [[location(0)]] vec4<f32> {
     var a : vec2<f32> = vec2<f32>();
-    gl_FragColor = vec4<f32>(0.4, 0.4, 0.8, 1.0);
     bar();
+    return vec4<f32>(0.4, 0.4, 0.8, 1.0);
 }

test/triangle.wgsl

@@ -18,18 +18,14 @@ const pos : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
     vec2<f32>(-0.5, -0.5),
     vec2<f32>(0.5, -0.5));
 
-[[builtin(position)]] var<out> Position : vec4<f32>;
-[[builtin(vertex_index)]] var<in> VertexIndex : i32;
-
 [[stage(vertex)]]
-fn vtx_main() -> void {
-  Position = vec4<f32>(pos[VertexIndex], 0.0, 1.0);
+fn vtx_main([[builtin(vertex_index)]] VertexIndex : i32)
+         -> [[builtin(position)]] vec4<f32> {
+  return vec4<f32>(pos[VertexIndex], 0.0, 1.0);
 }
 
 // Fragment shader
-[[location(0)]] var<out> outColor : vec4<f32>;
-
 [[stage(fragment)]]
-fn frag_main() -> void {
-  outColor = vec4<f32>(1.0, 0.0, 0.0, 1.0);
+fn frag_main() -> [[location(0)]] vec4<f32> {
+  return vec4<f32>(1.0, 0.0, 0.0, 1.0);
 }