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chip8-zig/src/main-scene.zig

364 lines
14 KiB
Zig

const Self = @This();
const rl = @import("raylib");
const std = @import("std");
const Gltf = @import("zgltf");
const GlobalContext = @import("./global-context.zig");
const EmulatorModel = @import("./emulator-model.zig");
const ChipContext = @import("chip.zig");
const RaylibChip = @import("raylib-chip.zig");
const assert = std.debug.assert;
const Allocator = std.mem.Allocator;
const StringList = std.ArrayList([]const u8);
ctx: *GlobalContext,
allocator: Allocator,
emulator: EmulatorModel,
camera_turn_vel: rl.Vector3 = rl.Vector3{ .x = 0, .y = 0, .z = 0 },
camera_target_orientation: ?rl.Vector3 = null,
previous_click_time: f64 = 0.0,
shader: rl.Shader,
lights: [2]Light,
chip: *ChipContext,
raylib_chip: *RaylibChip,
chip_sound: rl.Sound,
pub fn genSinWave(wave: *rl.Wave, frequency: f32) void {
assert(wave.sampleSize == 16); // Only 16 bits are supported
const sample_rate: f32 = @floatFromInt(wave.sampleRate);
const sample_size: u5 = @truncate(wave.sampleSize);
const max_sample_value: f32 = @floatFromInt(@shlExact(@as(u32, 1), sample_size - 1));
const data: [*]i16 = @ptrCast(@alignCast(wave.data));
for (0..wave.frameCount) |i| {
const i_f32: f32 = @floatFromInt(i);
const sin_value: f32 = @sin(std.math.pi*2*frequency/sample_rate*i_f32);
data[i] = @intFromFloat(sin_value*max_sample_value);
}
}
const Light = struct {
const LightType = enum(i32) {
DIRECTIONAL = 0,
POINT = 1,
};
type: LightType,
enabled: bool,
position: rl.Vector3,
target: rl.Vector3,
color: rl.Color,
attenuation: f32 = 0.0,
enabledLoc: i32,
typeLoc: i32,
positionLoc: i32,
targetLoc: i32,
colorLoc: i32,
attenuationLoc: i32 = 0,
fn getLightShaderLocation(shader: rl.Shader, idx: usize, comptime name: []const u8) i32 {
var buf: [128]u8 = undefined;
var fba = std.heap.FixedBufferAllocator.init(&buf);
const prop_name = std.fmt.allocPrintZ(fba.allocator(), "lights[{d}]." ++ name, .{idx}) catch unreachable;
return rl.GetShaderLocation(shader, prop_name);
}
pub fn init(idx: usize, light_type: LightType, postion: rl.Vector3, target: rl.Vector3, color: rl.Color, shader: rl.Shader) Light {
var light = Light{
.type = light_type,
.enabled = true,
.position = postion,
.target = target,
.color = color,
.enabledLoc = Light.getLightShaderLocation(shader, idx, "enabled"),
.typeLoc = Light.getLightShaderLocation(shader, idx, "type"),
.positionLoc = Light.getLightShaderLocation(shader, idx, "position"),
.targetLoc = Light.getLightShaderLocation(shader, idx, "target"),
.colorLoc = Light.getLightShaderLocation(shader, idx, "color"),
};
light.update_values(shader);
return light;
}
pub fn update_values(self: *Light, shader: rl.Shader) void {
const enabled: i32 = @intFromBool(self.enabled);
rl.SetShaderValue(shader, self.enabledLoc, &enabled, rl.ShaderUniformDataType.SHADER_UNIFORM_INT);
const lightType: i32 = @intFromEnum(self.type);
rl.SetShaderValue(shader, self.typeLoc, &lightType, rl.ShaderUniformDataType.SHADER_UNIFORM_INT);
const position = [3]f32{ self.position.x, self.position.y, self.position.z };
rl.SetShaderValue(shader, self.positionLoc, &position, rl.ShaderUniformDataType.SHADER_UNIFORM_VEC3);
const target = [3]f32{ self.target.x, self.target.y, self.target.z };
rl.SetShaderValue(shader, self.targetLoc, &target, rl.ShaderUniformDataType.SHADER_UNIFORM_VEC3);
const color = [4]f32{
@as(f32, @floatFromInt(self.color.r)) / 255.0,
@as(f32, @floatFromInt(self.color.g)) / 255.0,
@as(f32, @floatFromInt(self.color.b)) / 255.0,
@as(f32, @floatFromInt(self.color.a)) / 255.0,
};
rl.SetShaderValue(shader, self.colorLoc, &color, rl.ShaderUniformDataType.SHADER_UNIFORM_VEC4);
}
};
fn getCameraProjection(camera: *const rl.Camera3D) rl.Matrix {
const screen_width: f32 = @floatFromInt(rl.GetScreenWidth());
const screen_height: f32 = @floatFromInt(rl.GetScreenHeight());
if (camera.projection == .CAMERA_PERSPECTIVE) {
return rl.MatrixPerspective(camera.fovy*rl.DEG2RAD, screen_width/screen_height, rl.RL_CULL_DISTANCE_NEAR, rl.RL_CULL_DISTANCE_FAR);
} else if (camera.projection == .CAMERA_ORTHOGRAPHIC) {
const aspect = screen_width/screen_height;
const top = camera.fovy/2.0;
const right = top*aspect;
return rl.MatrixOrtho(-right, right, -top, top, rl.RL_CULL_DISTANCE_NEAR, rl.RL_CULL_DISTANCE_FAR);
} else {
unreachable;
}
}
fn getScreenDirectionFromCamera(mat_proj: *const rl.Matrix, mat_view: *const rl.Matrix, point: rl.Vector2) rl.Vector3 {
const screen_width: f32 = @floatFromInt(rl.GetScreenWidth());
const screen_height: f32 = @floatFromInt(rl.GetScreenHeight());
const ndc_x = (2.0*point.x) / screen_width - 1.0;
const ndc_y = 1.0 - (2.0*point.y) / screen_height;
var near_point = rl.Vector3Unproject(.{ .x = ndc_x, .y = ndc_y, .z = 0.0 }, mat_proj.*, mat_view.*);
var far_point = rl.Vector3Unproject(.{ .x = ndc_x, .y = ndc_y, .z = 1.0 }, mat_proj.*, mat_view.*);
return rl.Vector3Subtract(far_point, near_point).normalize();
}
fn getPrefferedDistanceToBox(camera: *const rl.Camera3D, box: rl.BoundingBox) f32 {
const screen_width: f32 = @floatFromInt(rl.GetScreenWidth());
const screen_height: f32 = @floatFromInt(rl.GetScreenHeight());
const margin = @min(screen_width, screen_height)*0.1;
const box_size = box.max.sub(box.min);
const max_model_scale = @min((screen_width-2*margin)/box_size.x, (screen_height-2*margin)/box_size.y);
// const model_screen_width = box_size.x * max_model_scale;
const model_screen_height = box_size.y * max_model_scale;
const mat_proj = getCameraProjection(camera);
const mat_view = rl.MatrixIdentity(); // rl.MatrixLookAt(camera.position, camera.target, camera.up);
const screen_middle = rl.Vector2{ .x = screen_width/2, .y = screen_height/2 };
const box_top_middle = screen_middle.add(.{ .y = -model_screen_height/2 });
const middle_dir = getScreenDirectionFromCamera(&mat_proj, &mat_view, screen_middle);
const top_middle_dir = getScreenDirectionFromCamera(&mat_proj, &mat_view, box_top_middle);
const angle = top_middle_dir.angleBetween(middle_dir);
const distance = 1/@tan(angle) * (box_size.y/2) + box_size.z/4;
return distance;
}
pub fn init(allocator: Allocator, ctx: *GlobalContext) !Self {
const shader = rl.LoadShader("src/shaders/main.vs", "src/shaders/main.fs");
shader.locs.?[@intFromEnum(rl.ShaderLocationIndex.SHADER_LOC_VECTOR_VIEW)] = rl.GetShaderLocation(shader, "viewPos");
const ambientLoc = rl.GetShaderLocation(shader, "ambient");
rl.SetShaderValue(shader, ambientLoc, &[4]f32{ 0.6, 0.6, 1, 1.0 }, .SHADER_UNIFORM_VEC4);
var light1 = Light.init(0, .DIRECTIONAL, rl.Vector3.new(0.2, 0, -0.2), rl.Vector3.zero(), rl.WHITE, shader);
var light2 = Light.init(1, .DIRECTIONAL, rl.Vector3.new(0.2, 0, 0.2), rl.Vector3.zero(), rl.WHITE, shader);
var chip = try allocator.create(ChipContext);
chip.* = try ChipContext.init(allocator);
const sample_rate = 44100;
var data = try allocator.alloc(i16, sample_rate);
defer allocator.free(data);
var chip_wave = rl.Wave{
.frameCount = sample_rate,
.sampleRate = sample_rate,
.sampleSize = 16,
.channels = 1,
.data = @ptrCast(data.ptr),
};
genSinWave(&chip_wave, 440);
var chip_sound = rl.LoadSoundFromWave(chip_wave);
rl.SetSoundVolume(chip_sound, 0.2);
var raylib_chip = try allocator.create(RaylibChip);
raylib_chip.* = RaylibChip.init(chip, chip_sound);
var emulator = try EmulatorModel.init(allocator, raylib_chip);
emulator.setShader(shader);
return Self {
.allocator = allocator,
.ctx = ctx,
.emulator = emulator,
.shader = shader,
.lights = .{light1, light2},
.chip = chip,
.raylib_chip = raylib_chip,
.chip_sound = chip_sound,
};
}
pub fn deinit(self: *Self) void {
self.emulator.deinit();
rl.UnloadSound(self.chip_sound);
self.chip.deinit();
self.allocator.destroy(self.raylib_chip);
self.allocator.destroy(self.chip);
}
fn updateCamera(self: *Self, dt: f32) void {
const mouse_delta = rl.GetMouseDelta();
const camera = &self.ctx.camera;
const emulator = &self.emulator;
if (rl.IsWindowResized()) {
const distance = getPrefferedDistanceToBox(camera, emulator.bbox);
const direction = camera.position.sub(emulator.position).normalize();
camera.position = emulator.position.add(direction.scale(distance));
}
if (rl.Vector3Equals(camera.position, rl.Vector3Zero()) == 1) {
const distance = getPrefferedDistanceToBox(camera, self.emulator.bbox);
camera.target = emulator.position;
camera.position = emulator.position.sub(rl.Vector3.new(0, 0, 1).scale(distance));
}
var camera_turn_acc = rl.Vector3Zero();
if (rl.IsMouseButtonDown(rl.MouseButton.MOUSE_BUTTON_LEFT)) {
if (@fabs(mouse_delta.x) > 5) {
const rotation_speed = 2; // Radians/second
camera_turn_acc.x = -rotation_speed*mouse_delta.x;
}
if (@fabs(mouse_delta.x) < 5) {
self.camera_turn_vel = self.camera_turn_vel.scale(0.90); // Holding drag
}
}
if (rl.IsMouseButtonPressed(rl.MouseButton.MOUSE_BUTTON_LEFT)) {
self.camera_target_orientation = null;
const now = rl.GetTime();
const duration_between_clicks = now - self.previous_click_time;
if (duration_between_clicks < 0.3) {
const ray = rl.GetMouseRay(rl.GetMousePosition(), camera.*);
const collision = rl.GetRayCollisionBox(ray, self.emulator.bbox);
if (collision.hit) {
const front_face_normal = rl.Vector3.new(0, 0, -1);
const back_face_normal = rl.Vector3.new(0, 0, 1);
if (rl.Vector3Equals(collision.normal, front_face_normal) == 1) {
self.camera_target_orientation = front_face_normal;
} else if (rl.Vector3Equals(collision.normal, back_face_normal) == 1) {
self.camera_target_orientation = back_face_normal;
}
}
}
self.previous_click_time = now;
}
if (self.camera_target_orientation) |target| {
const current_direction = camera.position.sub(emulator.position).normalize();
const current_angle = std.math.atan2(f32, current_direction.z, current_direction.x);
const target_angle = std.math.atan2(f32, target.z, target.x);
const diff_angle = std.math.pi - @mod((target_angle - current_angle) + 3*std.math.pi, 2*std.math.pi);
if (@fabs(diff_angle) < 0.001) {
self.camera_turn_vel.x = 0;
self.camera_target_orientation = null;
} else {
self.camera_turn_vel.x = diff_angle*3;
}
}
self.camera_turn_vel = self.camera_turn_vel.scale(0.95); // Ambient drag
self.camera_turn_vel = self.camera_turn_vel.add(camera_turn_acc.scale(dt));
const camera_min_vel = 0;
if (self.camera_turn_vel.length() > camera_min_vel) {
const rotation = rl.MatrixRotate(camera.up.normalize(), self.camera_turn_vel.x*dt);
var view = rl.Vector3Subtract(camera.position, camera.target);
view = rl.Vector3Transform(view, rotation);
camera.position = rl.Vector3Add(camera.target, view);
}
}
pub fn update(self: *Self, dt: f32) void {
self.updateCamera(dt);
const camera = &self.ctx.camera;
const cameraPos = [3]f32{ camera.position.x, camera.position.y, camera.position.z };
rl.SetShaderValue(self.shader, self.shader.locs.?[@intFromEnum(rl.ShaderLocationIndex.SHADER_LOC_VECTOR_VIEW)], &cameraPos, rl.ShaderUniformDataType.SHADER_UNIFORM_VEC3);
for (&self.lights) |*light| {
light.update_values(self.shader);
}
self.emulator.updateDisplay();
// {
// var matProj = rl.MatrixIdentity();
// // projection = CAMERA_PERSPECTIVE
// matProj = rl.MatrixPerspective(camera.fovy*rl.DEG2RAD, (screen_width/screen_height), rl.RL_CULL_DISTANCE_NEAR, rl.RL_CULL_DISTANCE_FAR);
//
// var matView = rl.MatrixLookAt(camera.position, camera.target, camera.up);
// // Convert world position vector to quaternion
// var worldPos = rl.Vector4{ .x = position.x, .y = position.y, .z = position.z, .w = 1.0 };
//
// std.debug.print("worldPos {}\n", .{worldPos});
// // Transform world position to view
// worldPos = rl.QuaternionTransform(worldPos, matView);
//
// // Transform result to projection (clip space position)
// worldPos = rl.QuaternionTransform(worldPos, matProj);
//
// // Calculate normalized device coordinates (inverted y)
// var ndcPos = rl.Vector3.new( worldPos.x/worldPos.w, -worldPos.y/worldPos.w, worldPos.z/worldPos.w );
//
// // Calculate 2d screen position vector
// screen_position = rl.Vector2{ .x = (ndcPos.x + 1.0)/2.0*screen_width, .y = (ndcPos.y + 1.0)/2.0*screen_height };
// }
// const target_screen_position = rl.Vector2{ .x = screen_width/2, .y = screen_height*0.1 };
// {
// var matProj = get_camera_projection(&camera);
// var matView = rl.MatrixLookAt(camera.position, camera.target, camera.up);
//
// const ndc_x = (2.0*target_screen_position.x) / screen_width - 1.0;
// const ndc_y = 1.0 - (2.0*target_screen_position.y) / screen_height;
//
// var near_point = rl.Vector3Unproject(.{ .x = ndc_x, .y = ndc_y, .z = 0.0 }, matProj, matView);
// var far_point = rl.Vector3Unproject(.{ .x = ndc_x, .y = ndc_y, .z = 1.0 }, matProj, matView);
//
// var direction = rl.Vector3Subtract(far_point, near_point).normalize();
//
// var origin: rl.Vector3 = undefined;
// if (camera.projection == .CAMERA_PERSPECTIVE) {
// origin = camera.position;
// } else {
// origin = rl.Vector3Unproject(.{ .x = ndc_x, .y = ndc_y, .z = -1.0 }, matProj, matView);
// }
//
// var world_pos = origin.add(direction.scale(3));
//
// model_position = world_pos;
// }
}
pub fn draw(self: *Self) void {
rl.BeginShaderMode(self.shader);
{
self.emulator.draw();
}
rl.EndShaderMode();
}