GPU Backend: Resource model refactor

pax-chassis-common/src/core_graphics_c_bridge.rs

@@ -128,6 +128,7 @@ pub extern "C" fn pax_tick(
         (
             CoreGraphicsContext::new_y_up(ctx, height as f64, None),
             Box::new(|| (/* clear screen here */)),
+            Box::new(|| (/* resize render texture backend here */)),
         )
     });
 

pax-pixels/src/render_backend/geometry.wgsl → pax-pixels/shaders/geometry.wgsl

@@ -4,18 +4,6 @@ struct Globals {
     _pad2: u32,
 };
 
-struct Primitive {
-    fill_id_and_type: u32,
-    z_index: i32,
-    clipping_id: u32, //not used atm
-    transform_id: u32,
-};
-
-struct Primitives {
-    primitives: array<Primitive, 512>,
-};
-
-
 struct Transform {
     // OBS transform: mat3x2<f32> has different alignment on WebGL vs for
     // example metal (don't change this unless you know what you are doing)
@@ -29,16 +17,8 @@ struct Transform {
     _pad2: u32,
 }
 
-struct Transforms {
-    transforms: array<Transform, 64>,
-}
-
-
-struct Colors {
-    colors: array<vec4<f32>, 512>,
-}
-
-struct Gradient {
+// TODO change type to support radius/solid etc
+struct MeshMetadata {
     colors: array<vec4<f32>, 8>,
     stops_set1: vec4<f32>,
     stops_set2: vec4<f32>,
@@ -47,19 +27,14 @@ struct Gradient {
     off_axis: vec2<f32>,
     stop_count: u32,
     type_id: u32,
-    _pad: array<vec4<u32>, 4>,
-}
-
-struct Gradients {
-    gradients: array<Gradient, 64>,
+    _pad0: array<vec4<u32>, 4>,
 }
 
 
 @group(0) @binding(0) var<uniform> globals: Globals;
-@group(0) @binding(1) var<uniform> u_primitives: Primitives;
-@group(0) @binding(2) var<uniform> transforms: Transforms;
-@group(0) @binding(3) var<uniform> colors: Colors;
-@group(0) @binding(4) var<uniform> gradients: Gradients;
+@group(0) @binding(1) var<uniform> transform: Transform;
+
+@group(1) @binding(0) var<uniform> mesh_metadata: MeshMetadata;
 
 struct GpuVertex {
     @location(0) position: vec2<f32>,
@@ -69,7 +44,6 @@ struct GpuVertex {
 
 struct VertexOutput {
     @builtin(position) clip_position: vec4<f32>,
-	@location(0) @interpolate(flat) prim_id: u32,
 };
 
 @vertex
@@ -78,55 +52,45 @@ fn vs_main(
 ) -> VertexOutput {
 	var out: VertexOutput;
     var p = model.position;
-
     // apply transform
-    let primitive = u_primitives.primitives[model.prim_id];
-    let m = transforms.transforms[primitive.transform_id];
-
+    let m = transform;
     let t_p_x = p.x * m.xx + p.y * m.yx + m.zx;
     let t_p_y = p.x * m.xy + p.y * m.yy + m.zy;
-
     var pos = vec2<f32>(t_p_x, t_p_y);
-
     pos /= globals.resolution;
     pos *= 2.0;
     pos -= 1.0;
     pos.y *= -1.0;
 
-    out.prim_id = model.prim_id;
     out.clip_position = vec4<f32>(pos, 0.0, 1.0);
     return out;
 }
 
 // Fragment shader
 @fragment
 fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
-
-    let primitive = u_primitives.primitives[in.prim_id];
-
     //color/gradient
-    let fill_id_and_type = primitive.fill_id_and_type;
-    //clipping rectangle
-    let fill_id = fill_id_and_type & 0xFFFFu;
-    let fill_type = fill_id_and_type >> 16u;
+    let type_id = mesh_metadata.type_id;
     var color: vec4<f32>;
-    if fill_type == 0u {
-        color = colors.colors[fill_id];
+    if type_id == 0u {
+        color = mesh_metadata.colors[0];
     } else {
         let p = in.clip_position.xy;
-        color = gradient(fill_id, p);
+        color = gradient(p);
     }
     return color;
 }
 
 
-fn gradient(fill_id: u32, coord: vec2<f32>) -> vec4<f32> {
-    let gradient = gradients.gradients[fill_id];
-
+fn gradient(coord: vec2<f32>) -> vec4<f32> {
+    let gradient = mesh_metadata;
     // Calculate color space position
     let g_p = gradient.position * f32(globals.dpr);
     let g_a = gradient.main_axis * f32(globals.dpr);
     let p_t = coord - g_p;
+
+    // TODO check type id here, and calculate color_space (0.0 to 1.0) using
+    // distance instead of projection to do radial gradients!
     let m_a_l = length(g_a);
     let n = g_a / m_a_l;
     let color_space = dot(p_t, n);

pax-pixels/src/render_backend/data.rs

@@ -32,7 +32,7 @@ const MAX_GRADIENT_STOPS: usize = 8;
 
 #[repr(C)]
 #[derive(Debug, Default, Copy, Clone, Pod, Zeroable)]
-pub(crate) struct GpuGradient {
+pub(crate) struct GpuMeshMetadata {
     pub colors: [[f32; 4]; MAX_GRADIENT_STOPS],
     pub stops: [f32; MAX_GRADIENT_STOPS],
     pub position: [f32; 2],