rotateTowards, key store, camera faces Z-, CCW frontface

src/data/keystore.zig

@@ -0,0 +1,68 @@
+pub fn KeyStore(comptime key_type: type, comptime buf_size: usize, comptime zero: key_type) type {
+    return struct {
+        just_pressed: [buf_size]key_type = .{zero} ** buf_size,
+        pressed: [buf_size]key_type = .{zero} ** buf_size,
+        just_released: [buf_size]key_type = .{zero} ** buf_size,
+
+        const Self = @This();
+        pub fn reset(self: *Self) void {
+            self.just_pressed = .{zero} ** buf_size;
+            self.just_released = .{zero} ** buf_size;
+        }
+        pub fn press(self: *Self, code: key_type) void {
+            for (self.pressed) |pressed| {
+                if (pressed == code) return;
+            }
+            for (&self.pressed) |*pressed| {
+                if (pressed.* == zero) {
+                    pressed.* = code;
+                    break;
+                }
+            }
+            for (self.just_pressed) |just_pressed| {
+                if (just_pressed == code) return;
+            }
+            for (&self.just_pressed) |*just_pressed| {
+                if (just_pressed.* == zero) {
+                    just_pressed.* = code;
+                    break;
+                }
+            }
+        }
+        pub fn release(self: *Self, code: key_type) void {
+            for (&self.pressed) |*pressed| {
+                if (pressed.* == code) {
+                    pressed.* = zero;
+                    break;
+                }
+            }
+            for (self.just_released) |just_released| {
+                if (just_released == code) return;
+            }
+            for (&self.just_released) |*just_released| {
+                if (just_released.* == zero) {
+                    just_released.* = code;
+                    break;
+                }
+            }
+        }
+        pub fn is_just_pressed(self: *Self, code: key_type) bool {
+            for (self.just_pressed) |just_pressed| {
+                if (just_pressed == code) return true;
+            }
+            return false;
+        }
+        pub fn is_pressed(self: *Self, code: key_type) bool {
+            for (self.pressed) |pressed| {
+                if (pressed == code) return true;
+            }
+            return false;
+        }
+        pub fn is_just_released(self: *Self, code: key_type) bool {
+            for (self.just_released) |just_released| {
+                if (just_released == code) return true;
+            }
+            return false;
+        }
+    };
+}

src/debug_scene.zig

@@ -1,5 +1,6 @@
 const std = @import("std");
 const sdl = @import("sdl");
+const Transform = @import("graphics/transform.zig");
 const Controller = @import("graph/controller.zig");
 const Graphics = @import("graphics.zig");
 const Game = @import("game.zig");
@@ -70,35 +71,48 @@ pub fn init(controller: *Controller, graphics: *Graphics) !void {
 pub fn deinit() void {}
 
 pub fn update(
+    cube: *Cube,
     mouse: *Game.Mouse,
     keyboard: *Game.Keyboard,
     graphics: *Graphics,
     time: *Game.Time,
 ) void {
-    if (keyboard.is_pressed(sdl.SCANCODE_W)) {
+    if (keyboard.keys.is_pressed(sdl.SCANCODE_W)) {
-        graphics.camera.transform.translateLocal(.{ 0.0, 0.0, 5.0 * time.delta });
-    }
-    if (keyboard.is_pressed(sdl.SCANCODE_S)) {
         graphics.camera.transform.translateLocal(.{ 0.0, 0.0, -5.0 * time.delta });
     }
-    if (keyboard.is_pressed(sdl.SCANCODE_D)) {
+    if (keyboard.keys.is_pressed(sdl.SCANCODE_S)) {
+        graphics.camera.transform.translateLocal(.{ 0.0, 0.0, 5.0 * time.delta });
+    }
+    if (keyboard.keys.is_pressed(sdl.SCANCODE_D)) {
         graphics.camera.transform.translateLocal(.{ 5.0 * time.delta, 0.0, 0.0 });
     }
-    if (keyboard.is_pressed(sdl.SCANCODE_A)) {
+    if (keyboard.keys.is_pressed(sdl.SCANCODE_A)) {
         graphics.camera.transform.translateLocal(.{ -5.0 * time.delta, 0.0, 0.0 });
     }
 
-    if (@abs(mouse.dx) < 0.01 and @abs(mouse.dy) < 0.01) return;
+    if (mouse.buttons.is_pressed(sdl.BUTTON_LEFT)) {
+        const scale = 1.0 / @as(f32, @floatFromInt(graphics.window_size[1]));
+        cube.transform.position[0] += mouse.dx * scale * 4.0;
+        cube.transform.position[1] -= mouse.dy * scale * 4.0;
 
-    const delta, const length = Graphics.Transform.extractNormal(.{ mouse.dy, mouse.dx, 0.0 });
+        const ORIGIN_DIR = @Vector(3, f32){ 0.0, 0.0, -1.0 };
-    const rot = Graphics.Transform.rotationByAxis(
+        const INIT_ROTATION = Transform.rotationByAxis(.{ 1.0, 0.0, 0.0 }, std.math.pi * 0.5);
-        delta,
+
-        length * std.math.pi / @as(f32, @floatFromInt(graphics.window_size[1])) * 2.0,
+        const ROTATED_DIR = Transform.rotateVector(ORIGIN_DIR, INIT_ROTATION);
+
+        graphics.camera.transform.rotation = Transform.combineRotations(
+            INIT_ROTATION,
+            Transform.rotationToward(ROTATED_DIR, cube.transform.position - graphics.camera.transform.position, .{ .normalize_to = true }),
         );
-    graphics.camera.transform.rotateLocal(rot);
+    }
 }
 
 pub fn draw(cube: *Cube, graphics: *Graphics) !void {
+    try graphics.drawMesh(cube.mesh, Graphics.Transform{
+        .position = .{ 0.0, 0.0, 0.0 },
+        .rotation = cube.transform.rotation,
+        .scale = cube.transform.scale,
+    });
     for (OFFSETS) |offset| {
         try graphics.drawMesh(cube.mesh, Graphics.Transform{
             .position = cube.transform.position + offset,

src/game.zig

@@ -27,6 +27,7 @@ pub fn init(alloc: std.mem.Allocator) GameError!Self {
     var controller = try graph.getController();
     controller.addResource(graphics);
     controller.addResource(Mouse{
+        .buttons = .{},
         .x = 0.0,
         .y = 0.0,
         .dx = 0.0,
@@ -106,7 +107,7 @@ fn processEvents(
 ) GameError!void {
     mouse.dx = 0.0;
     mouse.dy = 0.0;
-    keyboard.reset();
+    keyboard.keys.reset();
 
     sdl.PumpEvents();
     while (true) {
@@ -131,11 +132,19 @@ fn processEvents(
                 },
                 sdl.EVENT_KEY_DOWN => {
                     if (event.key.windowID != sdl.GetWindowID(graphics.window)) continue;
-                    keyboard.press(event.key.scancode);
+                    keyboard.keys.press(event.key.scancode);
                 },
                 sdl.EVENT_KEY_UP => {
                     if (event.key.windowID != sdl.GetWindowID(graphics.window)) continue;
-                    keyboard.release(event.key.scancode);
+                    keyboard.keys.release(event.key.scancode);
+                },
+                sdl.EVENT_MOUSE_BUTTON_DOWN => {
+                    if (event.button.windowID != sdl.GetWindowID(graphics.window)) continue;
+                    mouse.buttons.press(event.button.button);
+                },
+                sdl.EVENT_MOUSE_BUTTON_UP => {
+                    if (event.button.windowID != sdl.GetWindowID(graphics.window)) continue;
+                    mouse.buttons.release(event.button.button);
                 },
                 else => {},
             }

src/graphics.zig

@@ -189,7 +189,7 @@ pub fn create() GameError!Self {
 
         .camera = Camera{
             .transform = Transform{
-                .position = .{ 0.0, 0.0, -4.0 },
+                .position = .{ 0.0, 0.0, 4.0 },
             },
             .near = 1.0,
             .far = 1024.0,

src/graphics/camera.zig

@@ -17,8 +17,8 @@ pub fn matrix(camera: Camera) @Vector(16, f32) {
     const projection = @Vector(16, f32){
         xx, 0,  0,   0,
         0,  yy, 0,   0,
-        0,  0,  zz, wz,
+        0,  0,  -zz, wz,
-        0,  0,  1,  0,
+        0,  0,  -1,  0,
     };
     return Transform.multiplyMatrix(projection, camera.transform.inverseMatrix());
 }

src/graphics/presets.zig

@@ -20,5 +20,10 @@ pub const DEPTH_ENABLED = sdl.GPUDepthStencilState{
 pub const RASTERIZER_CULL = sdl.GPURasterizerState{
     .cull_mode = sdl.GPU_CULLMODE_BACK,
     .fill_mode = sdl.GPU_FILLMODE_FILL,
-    .front_face = sdl.GPU_FRONTFACE_CLOCKWISE,
+    .front_face = sdl.GPU_FRONTFACE_COUNTER_CLOCKWISE,
+};
+
+pub const RASTERIZER_NO_CULL = sdl.GPURasterizerState{
+    .cull_mode = sdl.GPU_CULLMODE_NONE,
+    .fill_mode = sdl.GPU_FILLMODE_FILL,
 };

src/graphics/transform.zig

@@ -58,10 +58,16 @@ pub fn translate(transform: *Transform, translation: Position) void {
 pub fn translateLocal(transform: *Transform, translation: Position) void {
     @setFloatMode(.optimized);
 
-    const a = transform.rotation[0];
+    transform.position += rotateVector(translation, transform.rotation);
-    const b = transform.rotation[1];
+}
-    const c = transform.rotation[2];
+
-    const d = transform.rotation[3];
+pub fn rotateVector(vector: Position, rotation: Rotation) Position {
+    @setFloatMode(.optimized);
+
+    const a = rotation[0];
+    const b = rotation[1];
+    const c = rotation[2];
+    const d = rotation[3];
 
     const s = 2.0 / (a * a + b * b + c * c + d * d);
     const bs = b * s;
@@ -78,9 +84,11 @@ pub fn translateLocal(transform: *Transform, translation: Position) void {
     const cd = c * ds;
     const dd = d * ds;
 
-    transform.position[0] += translation[0] * (1 - cc - dd) + translation[1] * (bc - ad) + translation[2] * (bd + ac);
+    return .{
-    transform.position[1] += translation[0] * (bc + ad) + translation[1] * (1 - bb - dd) + translation[2] * (cd - ab);
+        vector[0] * (1 - cc - dd) + vector[1] * (bc - ad) + vector[2] * (bd + ac),
-    transform.position[2] += translation[0] * (bd - ac) + translation[1] * (cd + ab) + translation[2] * (1 - bb - cc);
+        vector[0] * (bc + ad) + vector[1] * (1 - bb - dd) + vector[2] * (cd - ab),
+        vector[0] * (bd - ac) + vector[1] * (cd + ab) + vector[2] * (1 - bb - cc),
+    };
 }
 
 pub fn rotate(transform: *Transform, rotation: Rotation) void {
@@ -95,11 +103,49 @@ pub fn rotateLocal(transform: *Transform, rotation: Rotation) void {
     transform.rotation = normalizeRotation(combineRotations(rotation, transform.rotation));
 }
 
+pub fn rotateByAxis(transform: *Transform, axis: Position, angle: f32) void {
+    transform.rotate(rotationByAxis(axis, angle));
+}
+
+pub fn rotateToward(transform: *Transform, target: Position, origin_norm: Position) void {
+    @setFloatMode(.optimized);
+
+    transform.rotation = rotationToward(origin_norm, target - transform.position, .{ .normalize_to = true });
+}
+
+const RotationTowardOptions = struct {
+    normalize_from: bool = false,
+    normalize_to: bool = false,
+};
+pub fn rotationToward(from: Position, to: Position, comptime options: RotationTowardOptions) Rotation {
+    @setFloatMode(.optimized);
+
+    const from_norm = if (options.normalize_from) extractNormal(from)[0] else from;
+    const to_norm = if (options.normalize_to) extractNormal(to)[0] else to;
+
+    const combined = combineRotations(.{
+        0.0, to_norm[0], to_norm[1], to_norm[2],
+    }, .{
+        0.0, from_norm[0], from_norm[1], from_norm[2],
+    });
+    return normalizeRotation(.{
+        1 - combined[0],
+        combined[1],
+        combined[2],
+        combined[3],
+    });
+}
+
 pub fn normalizeRotation(r: Rotation) Rotation {
     @setFloatMode(.optimized);
 
-    const length_inverse = 1.0 / @sqrt(r[0] * r[0] + r[1] * r[1] + r[2] * r[2] + r[3] * r[3]);
+    const length = @sqrt(r[0] * r[0] + r[1] * r[1] + r[2] * r[2] + r[3] * r[3]);
+    if (length <= 1e-15) {
+        return .{ 1.0, 0.0, 0.0, 0.0 };
+    } else {
+        const length_inverse = 1.0 / length;
         return r * @as(Rotation, @splat(length_inverse));
+    }
 }
 
 pub fn combineRotations(a: Rotation, b: Rotation) Rotation {
@@ -113,11 +159,11 @@ pub fn combineRotations(a: Rotation, b: Rotation) Rotation {
     };
 }
 
-pub fn rotationByAxis(axis: Position, rotation: f32) Rotation {
+pub fn rotationByAxis(axis: Position, angle: f32) Rotation {
     @setFloatMode(.optimized);
 
-    const cos = std.math.cos(rotation * 0.5);
+    const cos = std.math.cos(angle * 0.5);
-    const sin = std.math.sin(rotation * 0.5);
+    const sin = std.math.sin(angle * 0.5);
 
     return .{ cos, sin * axis[0], sin * axis[1], sin * axis[2] };
 }

src/keyboard.zig

@@ -1,69 +1,4 @@
 const sdl = @import("sdl");
+const key_store = @import("data/keystore.zig");
 
-const BUFFER_SIZE = 16;
+keys: key_store.KeyStore(sdl.Scancode, 16, sdl.SCANCODE_UNKNOWN) = .{},
-const ZERO = sdl.SCANCODE_UNKNOWN;
-
-just_pressed: [BUFFER_SIZE]sdl.Scancode = .{ZERO} ** BUFFER_SIZE,
-pressed: [BUFFER_SIZE]sdl.Scancode = .{ZERO} ** BUFFER_SIZE,
-just_released: [BUFFER_SIZE]sdl.Scancode = .{ZERO} ** BUFFER_SIZE,
-
-const Self = @This();
-pub fn reset(self: *Self) void {
-    self.just_pressed = .{ZERO} ** BUFFER_SIZE;
-    self.just_released = .{ZERO} ** BUFFER_SIZE;
-}
-pub fn press(self: *Self, code: sdl.Scancode) void {
-    for (self.pressed) |pressed| {
-        if (pressed == code) return;
-    }
-    for (&self.pressed) |*pressed| {
-        if (pressed.* == ZERO) {
-            pressed.* = code;
-            break;
-        }
-    }
-    for (self.just_pressed) |just_pressed| {
-        if (just_pressed == code) return;
-    }
-    for (&self.just_pressed) |*just_pressed| {
-        if (just_pressed.* == ZERO) {
-            just_pressed.* = code;
-            break;
-        }
-    }
-}
-pub fn release(self: *Self, code: sdl.Scancode) void {
-    for (&self.pressed) |*pressed| {
-        if (pressed.* == code) {
-            pressed.* = ZERO;
-            break;
-        }
-    }
-    for (self.just_released) |just_released| {
-        if (just_released == code) return;
-    }
-    for (&self.just_released) |*just_released| {
-        if (just_released.* == ZERO) {
-            just_released.* = code;
-            break;
-        }
-    }
-}
-pub fn is_just_pressed(self: *Self, code: sdl.Scancode) bool {
-    for (self.just_pressed) |just_pressed| {
-        if (just_pressed == code) return true;
-    }
-    return false;
-}
-pub fn is_pressed(self: *Self, code: sdl.Scancode) bool {
-    for (self.pressed) |pressed| {
-        if (pressed == code) return true;
-    }
-    return false;
-}
-pub fn is_just_released(self: *Self, code: sdl.Scancode) bool {
-    for (self.just_released) |just_released| {
-        if (just_released == code) return true;
-    }
-    return false;
-}

src/mouse.zig

@@ -1,3 +1,8 @@
+const sdl = @import("sdl");
+const key_store = @import("data/keystore.zig");
+
+buttons: key_store.KeyStore(@TypeOf(sdl.BUTTON_LEFT), 4, 0),
+
 x: f32,
 y: f32,
 dx: f32,