Meshes, mesh drawing and debug scene

src/debug_scene.zig

@@ -0,0 +1,91 @@
+const std = @import("std");
+const sdl = @import("sdl");
+const Controller = @import("graph/controller.zig");
+const Graphics = @import("graphics.zig");
+const Game = @import("game.zig");
+
+const CUBE_MESH_DATA = [_]f32{
+    -1, 1,  -1,
+    1,  1,  -1,
+    -1, -1, -1,
+    1,  -1, -1,
+    -1, -1, -1,
+    1,  1,  -1,
+    1,  1,  -1,
+    1,  1,  1,
+    1,  -1, -1,
+    1,  -1, 1,
+    1,  -1, -1,
+    1,  1,  1,
+    1,  1,  1,
+    -1, 1,  1,
+    1,  -1, 1,
+    -1, -1, 1,
+    1,  -1, 1,
+    -1, 1,  1,
+    -1, 1,  1,
+    -1, 1,  -1,
+    -1, -1, 1,
+    -1, -1, -1,
+    -1, -1, 1,
+    -1, 1,  -1,
+    -1, 1,  1,
+    1,  1,  1,
+    -1, 1,  -1,
+    1,  1,  -1,
+    -1, 1,  -1,
+    1,  1,  1,
+    -1, -1, -1,
+    1,  -1, -1,
+    -1, -1, 1,
+    1,  -1, 1,
+    -1, -1, 1,
+    1,  -1, -1,
+};
+
+const OFFSETS = [_]@Vector(3, f32){
+    .{ -3, 3, 0 },
+    .{ 0, 3, 0 },
+    .{ 3, 3, 0 },
+    .{ -3, 0, 0 },
+    .{ 0, 0, 0 },
+    .{ 3, 0, 0 },
+    .{ -3, -3, 0 },
+    .{ 0, -3, 0 },
+    .{ 3, -3, 0 },
+};
+
+pub const Cube = struct {
+    mesh: Graphics.Mesh,
+    transform: Graphics.Transform,
+};
+
+pub fn init(controller: *Controller, graphics: *Graphics) !void {
+    controller.addResource(Cube{
+        .mesh = try graphics.loadMesh(@ptrCast(&CUBE_MESH_DATA)),
+        .transform = Graphics.Transform{},
+    });
+}
+
+pub fn deinit() void {}
+
+pub fn update(cube: *Cube, mouse: *Game.Mouse, graphics: *Graphics) void {
+    if (@abs(mouse.dx) < 0.01 and @abs(mouse.dy) < 0.01) return;
+
+    const delta, const length = Graphics.Transform.extractNormal(.{ -mouse.dy, -mouse.dx, 0.0 });
+    const rot = Graphics.Transform.rotationByAxis(
+        delta,
+        length * std.math.pi / @as(f32, @floatFromInt(graphics.window_size[1])) * 2.0,
+    );
+    cube.transform.rotate(rot);
+}
+
+pub fn draw(cube: *Cube, graphics: *Graphics) !void {
+    for (OFFSETS) |offset| {
+        try graphics.drawMesh(cube.mesh, Graphics.Transform{
+            .position = cube.transform.position + offset,
+            .rotation = cube.transform.rotation,
+            .scale = cube.transform.scale,
+        });
+    }
+}