client gfx refactor (11): wgpu stream

alvr/client_core/resources/lobby_quad.wgsl

@@ -7,7 +7,7 @@ struct VertexOutput {
 @group(0) @binding(1) var hud_sampler: sampler;
 
 struct PushConstant {
-    transform: mat4x4f, // alignment
+    transform: mat4x4f,
     object_type: u32,
     floor_side: f32,
 }
@@ -28,7 +28,7 @@ fn vertex_main(@builtin(vertex_index) vertex_index: u32) -> VertexOutput {
 
 @fragment
 fn fragment_main(@location(0) uv: vec2f) -> @location(0) vec4f {
-    if pc.object_type == 0 {
+    if pc.object_type == 0 { // Ground
         let world_xz = (uv - 0.5) * pc.floor_side;
 
         let ground_center = vec3f(0.0, 0.0, 0.0);
@@ -73,7 +73,7 @@ fn fragment_main(@location(0) uv: vec2f) -> @location(0) vec4f {
         }
 
         return vec4f(out_color, 1.0);
-    } else {
+    } else { // HUD
         let mask = textureSample(hud_texture, hud_sampler, uv).a;
 
         return vec4<f32>(1.0, 1.0, 1.0, mask);

alvr/client_core/resources/stream.wgsl

@@ -0,0 +1,60 @@
+// todo: use expression directly when supported in naga
+const DIV12: f32 = 0.0773993808;// 1.0 / 12.92
+const DIV1: f32 = 0.94786729857; // 1.0 / 1.055
+const THRESHOLD: f32 = 0.04045;
+const GAMMA: vec3f = vec3f(2.4);
+
+// Convert from limited colors to full
+const LIMITED_MIN: f32 = 0.06274509803; // 16.0 / 255.0
+const LIMITED_MAX: f32 = 0.92156862745; // 235.0 / 255.0
+
+override FIX_LIMITED_RANGE: bool;
+override ENABLE_SRGB_CORRECTION: bool;
+override ENCODING_GAMMA: f32;
+
+var<push_constant> view_idx: u32;
+
+struct VertexOutput {
+    @builtin(position) position: vec4f,
+    @location(0) uv: vec2f,
+}
+
+@group(0) @binding(0) var stream_texture: texture_2d<f32>;
+@group(0) @binding(1) var stream_sampler: sampler;
+
+@vertex
+fn vertex_main(@builtin(vertex_index) vertex_index: u32) -> VertexOutput {
+    var result: VertexOutput;
+
+    let screen_uv = vec2f(f32(vertex_index & 1), f32(vertex_index >> 1));
+    result.position = vec4f((screen_uv - vec2f(0.5, 0.5)) * 2.0, 0.0, 1.0);
+    result.uv = vec2f((screen_uv.x + f32(view_idx)) / 2.0, screen_uv.y);
+
+    return result;
+}
+
+@fragment
+fn fragment_main(@location(0) uv: vec2f) -> @location(0) vec4f {
+    var result: vec3f = textureSample(stream_texture, stream_sampler, uv).rgb;
+
+    if FIX_LIMITED_RANGE {
+        // For some reason, the encoder shifts full-range color into the negatives and over one.
+        result = LIMITED_MIN + ((LIMITED_MAX - LIMITED_MIN) * result);
+    }
+
+    if ENABLE_SRGB_CORRECTION {
+        let condition = vec3f(f32(result.r < THRESHOLD), f32(result.g < THRESHOLD), f32(result.b < THRESHOLD));
+        let lowValues = result * DIV12;
+        let highValues = pow((result + vec3f(0.055)) * DIV1, GAMMA);
+        result = condition * lowValues + (1.0 - condition) * highValues;
+    }
+
+    if ENCODING_GAMMA != 0.0 {
+        let enc_condition = vec3f(f32(result.r < 0.0), f32(result.g < 0.0), f32(result.b < 0.0));
+        let enc_lowValues = result;
+        let enc_highValues = pow(result, vec3f(ENCODING_GAMMA));
+        result = enc_condition * enc_lowValues + (1.0 - enc_condition) * enc_highValues;
+    }
+
+    return vec4f(result, 1.0);
+}

alvr/client_core/src/c_api.rs

@@ -776,6 +776,7 @@ pub unsafe extern "C" fn alvr_start_stream_opengl(config: AlvrStreamConfig) {
         GRAPHICS_CONTEXT.with_borrow(|c| c.as_ref().unwrap().clone()),
         view_resolution,
         swapchain_textures,
+        glow::RGBA8,
         foveated_encoding,
         true,
         false, // TODO: limited range fix config

alvr/client_core/src/graphics/lobby.rs

@@ -1,4 +1,4 @@
-use super::{GraphicsContext, RenderViewInput};
+use super::{GraphicsContext, SDR_FORMAT};
 use alvr_common::{
     glam::{Mat4, UVec2, Vec3, Vec4},
     Fov, Pose,
@@ -17,7 +17,7 @@ use wgpu::{
     PrimitiveTopology, PushConstantRange, RenderPass, RenderPassColorAttachment,
     RenderPassDescriptor, RenderPipeline, RenderPipelineDescriptor, SamplerBindingType,
     SamplerDescriptor, ShaderModuleDescriptor, ShaderStages, StoreOp, Texture, TextureAspect,
-    TextureFormat, TextureSampleType, TextureView, TextureViewDimension, VertexState,
+    TextureSampleType, TextureView, TextureViewDimension, VertexState,
 };
 
 const FLOOR_SIDE: f32 = 300.0;
@@ -76,7 +76,7 @@ fn projection_from_fov(fov: Fov) -> Mat4 {
     .transpose()
 }
 
-fn pipeline(
+fn create_pipeline(
     device: &Device,
     label: &str,
     bind_group_layouts: &[&BindGroupLayout],
@@ -113,7 +113,7 @@ fn pipeline(
             entry_point: "fragment_main",
             compilation_options: Default::default(),
             targets: &[Some(ColorTargetState {
-                format: TextureFormat::Rgba8Unorm,
+                format: SDR_FORMAT,
                 blend: Some(BlendState {
                     color: BlendComponent {
                         src_factor: BlendFactor::SrcAlpha,
@@ -133,6 +133,12 @@ fn pipeline(
     })
 }
 
+pub struct RenderViewInput {
+    pub pose: Pose,
+    pub fov: Fov,
+    pub swapchain_index: u32,
+}
+
 pub struct LobbyRenderer {
     context: Rc<GraphicsContext>,
     quad_pipeline: RenderPipeline,
@@ -151,7 +157,8 @@ impl LobbyRenderer {
     ) -> Self {
         let device = &context.device;
 
-        let hud_texture = super::create_texture(device, UVec2::ONE * HUD_TEXTURE_SIDE as u32);
+        let hud_texture =
+            super::create_texture(device, UVec2::ONE * HUD_TEXTURE_SIDE as u32, SDR_FORMAT);
 
         let bind_group_layout = device.create_bind_group_layout(&BindGroupLayoutDescriptor {
             label: None,
@@ -175,7 +182,7 @@ impl LobbyRenderer {
             ],
         });
 
-        let quad_pipeline = pipeline(
+        let quad_pipeline = create_pipeline(
             device,
             "lobby_quad",
             &[&bind_group_layout],
@@ -184,7 +191,7 @@ impl LobbyRenderer {
             PrimitiveTopology::TriangleStrip,
         );
 
-        let line_pipeline = pipeline(
+        let line_pipeline = create_pipeline(
             device,
             "lobby_line",
             &[],
@@ -217,8 +224,8 @@ impl LobbyRenderer {
         });
 
         let render_targets = [
-            super::create_gl_swapchain(device, &swapchain_textures[0], view_resolution),
-            super::create_gl_swapchain(device, &swapchain_textures[1], view_resolution),
+            super::create_gl_swapchain(device, &swapchain_textures[0], view_resolution, SDR_FORMAT),
+            super::create_gl_swapchain(device, &swapchain_textures[1], view_resolution, SDR_FORMAT),
         ];
 
         let this = Self {