Update project

Source/Render/Instance.rs

@@ -0,0 +1,71 @@
+use bytemuck::{Pod, Zeroable};
+use std::mem;
+
+pub const NUM_INSTANCES_PER_ROW: u32 = 10;
+pub const NUM_INSTANCES: u32 = NUM_INSTANCES_PER_ROW * NUM_INSTANCES_PER_ROW;
+
+pub const INSTANCE_DISPLACEMENT: cgmath::Vector3<f32> = cgmath::Vector3::new(
+    NUM_INSTANCES_PER_ROW as f32 * 0.5,
+    0.0,
+    NUM_INSTANCES_PER_ROW as f32 * 0.5,
+);
+
+pub struct Instance {
+    pub position: cgmath::Vector3<f32>,
+    pub rotation: cgmath::Quaternion<f32>,
+}
+
+impl Instance {
+    pub fn ToRaw(&self) -> InstanceRaw {
+        InstanceRaw {
+            model: (cgmath::Matrix4::from_translation(self.position)
+                * cgmath::Matrix4::from(self.rotation))
+            .into(),
+        }
+    }
+}
+
+#[repr(C)]
+#[derive(Copy, Clone, Pod, Zeroable)]
+pub struct InstanceRaw {
+    pub model: [[f32; 4]; 4],
+}
+
+impl InstanceRaw {
+    pub fn GetDescriptor<'a>() -> wgpu::VertexBufferLayout<'a> {
+        wgpu::VertexBufferLayout {
+            array_stride: mem::size_of::<InstanceRaw>() as wgpu::BufferAddress,
+            // We need to switch from using a step mode of Vertex to Instance
+            // This means that our shaders will only change to use the next
+            // instance when the shader starts processing a new instance
+            step_mode: wgpu::VertexStepMode::Instance,
+            attributes: &[
+                wgpu::VertexAttribute {
+                    offset: 0,
+                    // While our vertex shader only uses locations 0, and 1 now, in later tutorials we'll
+                    // be using 2, 3, and 4, for Vertex. We'll start at slot 5 not conflict with them later
+                    shader_location: 5,
+                    format: wgpu::VertexFormat::Float32x4,
+                },
+                // A mat4 takes up 4 vertex slots as it is technically 4 vec4s. We need to define a slot
+                // for each vec4. We'll have to reassemble the mat4 in
+                // the shader.
+                wgpu::VertexAttribute {
+                    offset: mem::size_of::<[f32; 4]>() as wgpu::BufferAddress,
+                    shader_location: 6,
+                    format: wgpu::VertexFormat::Float32x4,
+                },
+                wgpu::VertexAttribute {
+                    offset: mem::size_of::<[f32; 8]>() as wgpu::BufferAddress,
+                    shader_location: 7,
+                    format: wgpu::VertexFormat::Float32x4,
+                },
+                wgpu::VertexAttribute {
+                    offset: mem::size_of::<[f32; 12]>() as wgpu::BufferAddress,
+                    shader_location: 8,
+                    format: wgpu::VertexFormat::Float32x4,
+                },
+            ],
+        }
+    }
+}