render-zig

commit 90b9db3b68b366a0a54bb1770ac600d859f8feb5
parent 04d09de0b45d9d57e623811aa525fd7ad9f0aca2
Author: Christian Ermann <christianermann@gmail.com>
Date:   Sun,  8 Dec 2024 22:22:14 -0800

Add cube sphere

Diffstat:
A
src/cubesphere.zig
 | 
29
+++++++++++++++++++++++++++++
M
src/main.zig
 | 
10
++++++++++

2 files changed, 39 insertions(+), 0 deletions(-)
diff --git a/src/cubesphere.zig b/src/cubesphere.zig
@@ -0,0 +1,29 @@
+const std = @import("std");
+
+const Mesh = @import("mesh.zig");
+const generateCube = @import("cube.zig").generateCube;
+const f32x3_normalize = @import("camera.zig").f32x3_normalize;
+const f32x3_mul = @import("camera.zig").f32x3_mul;
+
+const f32x3 = @Vector(3, f32);
+const f32x4 = @Vector(4, f32);
+
+pub fn generateCubeSphere(
+    n_subdivisions: u32,
+    allocator: std.mem.Allocator,
+) !Mesh {
+    const mesh = try generateCube(n_subdivisions, allocator);
+    const up = f32x3{ 0, 1, 0 };
+    for (
+        mesh.positions,
+        mesh.normals,
+        mesh.tangents,
+        mesh.bitangents,
+    ) |*position, *normal, *tangent, *bitangent| {
+        normal.* = f32x3_normalize(.{ position[0], position[1], position[2] });
+        position.* = .{ normal[0], normal[1], normal[2], 1.0 };
+        tangent.* = f32x3_normalize(f32x3_mul(up, normal.*));
+        bitangent.* = f32x3_mul(normal.*, tangent.*);
+    }
+    return mesh;
+}
diff --git a/src/main.zig b/src/main.zig
@@ -434,6 +434,9 @@ pub fn main() !void {
     const generateCube = @import("cube.zig").generateCube;
     const cube_mesh = try generateCube(1, allocator);
 
+    const generateCubeSphere = @import("cubesphere.zig").generateCubeSphere;
+    const cubesphere_mesh = try generateCubeSphere(16, allocator);
+
     var rp = try MeshRenderPipeline.init(
         &app,
         .{
@@ -466,6 +469,7 @@ pub fn main() !void {
     var transform_2 = Transform{};
     var transform_3 = Transform{ .offset = .{ 3, 3, 3 } };
     var transform_4 = Transform{ .offset = .{ -3, -3, 0 } };
+    var transform_5 = Transform{ .offset = .{ 3, -3, 1 } };
 
     var render_mesh = try render_data.addMesh(
         &transform_1,
@@ -491,6 +495,12 @@ pub fn main() !void {
         allocator,
     );
 
+    _ = try render_data.addMesh(
+        &transform_5,
+        &cubesphere_mesh,
+        allocator,
+    );
+
     const corners = mesh.bboxVertices();
     const bbox_indices = Mesh.bboxIndices();