sneak/Shared/SneakGame.cs
Colin McMillen 93a5d477bb New FOV algorithm that works pretty well.
Saved for posterity here, approximately:
https://twitter.com/mcmillen/status/1227326054949408768

GitOrigin-RevId: e960dad1d9241c08dbf1292c6856311d4ebd7a85
2020-02-13 14:55:02 -05:00

283 lines
9.9 KiB
C#

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using System;
using System.Collections.Generic;
namespace SemiColinGames {
public class SneakGame : Game {
const int TARGET_FPS = 60;
const double TARGET_FRAME_TIME = 1.0 / TARGET_FPS;
readonly GraphicsDeviceManager graphics;
RenderTarget2D sceneTarget;
RenderTarget2D lightingTarget;
BasicEffect lightingEffect;
SpriteBatch spriteBatch;
SpriteFont font;
bool fullScreen = false;
bool paused = false;
IDisplay display;
readonly History<Input> input = new History<Input>(2);
readonly FpsCounter fpsCounter = new FpsCounter();
readonly Timer updateTimer = new Timer(TARGET_FRAME_TIME / 2.0, "UpdateTimer");
readonly Timer drawTimer = new Timer(TARGET_FRAME_TIME / 2.0, "DrawTimer");
// Draw() needs to be called without IsRunningSlowly this many times before we actually
// attempt to draw the scene. This is a workaround for the fact that otherwise the first few
// frames can be really slow to draw.
int framesToSuppress = 2;
Texture2D grasslandBg1;
Texture2D grasslandBg2;
Player player;
World world;
readonly Camera camera = new Camera();
public SneakGame() {
graphics = new GraphicsDeviceManager(this) {
SynchronizeWithVerticalRetrace = true,
GraphicsProfile = GraphicsProfile.HiDef
};
IsFixedTimeStep = true;
TargetElapsedTime = TimeSpan.FromSeconds(TARGET_FRAME_TIME);
IsMouseVisible = true;
Content.RootDirectory = "Content";
}
// Performs initialization that's needed before starting to run.
protected override void Initialize() {
display = (IDisplay) Services.GetService(typeof(IDisplay));
display.Initialize(Window, graphics);
display.SetFullScreen(fullScreen);
Debug.Initialize(GraphicsDevice);
sceneTarget = new RenderTarget2D(
GraphicsDevice, camera.Width, camera.Height, false /* mipmap */,
GraphicsDevice.PresentationParameters.BackBufferFormat, DepthFormat.Depth24);
lightingTarget = new RenderTarget2D(
GraphicsDevice, camera.Width, camera.Height, false /* mipmap */,
GraphicsDevice.PresentationParameters.BackBufferFormat, DepthFormat.Depth24);
lightingEffect = new BasicEffect(GraphicsDevice);
lightingEffect.World = Matrix.CreateTranslation(0, 0, 0);
lightingEffect.View = Matrix.CreateLookAt(Vector3.Backward, Vector3.Zero, Vector3.Up);
lightingEffect.VertexColorEnabled = true;
RasterizerState rasterizerState = new RasterizerState() {
CullMode = CullMode.None
};
GraphicsDevice.RasterizerState = rasterizerState;
base.Initialize();
}
// Called once per game. Loads all game content.
protected override void LoadContent() {
spriteBatch = new SpriteBatch(GraphicsDevice);
font = Content.Load<SpriteFont>("font");
player = new Player(Content.Load<Texture2D>("Ninja_Female"));
world = new World(Content.Load<Texture2D>("grassland"), Levels.ONE_ONE);
grasslandBg1 = Content.Load<Texture2D>("grassland_bg1");
grasslandBg2 = Content.Load<Texture2D>("grassland_bg2");
}
// Called once per game. Unloads all game content.
protected override void UnloadContent() {
updateTimer.DumpStats();
drawTimer.DumpStats();
}
// Updates the game world.
protected override void Update(GameTime gameTime) {
updateTimer.Start();
input.Add(new Input(GamePad.GetState(PlayerIndex.One), Keyboard.GetState()));
if (input[0].Exit) {
Exit();
}
if (input[0].Pause && !input[1].Pause) {
paused = !paused;
}
if (input[0].FullScreen && !input[1].FullScreen) {
fullScreen = !fullScreen;
display.SetFullScreen(fullScreen);
}
Debug.Clear(paused);
if (input[0].Debug && !input[1].Debug) {
Debug.Enabled = !Debug.Enabled;
}
if (!paused) {
float modelTime = (float) gameTime.ElapsedGameTime.TotalSeconds;
Clock.AddModelTime(modelTime);
player.Update(modelTime, input, world.CollisionTargets);
camera.Update(player.Position, world.Width);
}
base.Update(gameTime);
updateTimer.Stop();
}
// Called when the game should draw itself.
protected override void Draw(GameTime gameTime) {
drawTimer.Start();
if (framesToSuppress > 0 && !gameTime.IsRunningSlowly) {
framesToSuppress--;
}
// We need to update the FPS counter in Draw() since Update() might get called more
// frequently, especially when gameTime.IsRunningSlowly.
fpsCounter.Update();
string fpsText = $"{GraphicsDevice.Viewport.Width}x{GraphicsDevice.Viewport.Height}, " +
$"{fpsCounter.Fps} FPS";
if (paused) {
fpsText += " (paused)";
}
Debug.SetFpsText(fpsText);
// Draw scene to sceneTarget.
GraphicsDevice.SetRenderTarget(sceneTarget);
GraphicsDevice.Clear(Color.CornflowerBlue);
spriteBatch.Begin(SpriteSortMode.Deferred, null, SamplerState.LinearWrap, null, null);
// Draw background.
Rectangle bgSource = new Rectangle(
(int) (camera.Left * 0.25), 0, camera.Width, camera.Height);
Rectangle bgTarget = new Rectangle(0, 0, camera.Width, camera.Height);
spriteBatch.Draw(grasslandBg2, bgTarget, bgSource, Color.White);
bgSource = new Rectangle(
(int) (camera.Left * 0.5), 0, camera.Width, camera.Height);
spriteBatch.Draw(grasslandBg1, bgTarget, bgSource, Color.White);
spriteBatch.End();
// Set up transformation matrix for drawing world objects.
Matrix transform = Matrix.CreateTranslation(-camera.Left, -camera.Top, 0);
spriteBatch.Begin(
SpriteSortMode.Deferred, null, SamplerState.LinearWrap, null, null, null, transform);
// Draw player.
player.Draw(spriteBatch);
// Draw foreground tiles.
world.Draw(spriteBatch);
// Draw debug rects & lines.
Debug.Draw(spriteBatch);
// Aaaaand we're done.
spriteBatch.End();
// Draw lighting to lightingTarget.
GraphicsDevice.SetRenderTarget(lightingTarget);
GraphicsDevice.Clear(new Color(0, 0, 0, 0f));
lightingEffect.Projection = camera.Projection;
DrawFov();
// Draw sceneTarget to screen.
GraphicsDevice.SetRenderTarget(null);
GraphicsDevice.Clear(Color.CornflowerBlue);
if (framesToSuppress == 0) {
spriteBatch.Begin(SpriteSortMode.Immediate, BlendState.AlphaBlend,
SamplerState.PointClamp, DepthStencilState.Default,
RasterizerState.CullNone);
Rectangle drawRect = new Rectangle(
0, 0, GraphicsDevice.Viewport.Width, GraphicsDevice.Viewport.Height);
spriteBatch.Draw(sceneTarget, drawRect, Color.White);
spriteBatch.Draw(lightingTarget, drawRect, Color.White);
// Draw debug toasts.
Debug.DrawToasts(spriteBatch, font);
spriteBatch.End();
}
base.Draw(gameTime);
drawTimer.Stop();
}
private void DrawFov() {
// TODO: DrawIndexedPrimitives
Color color = Color.FromNonPremultiplied(new Vector4(0, 0, 1, 0.6f));
Vector2 eyePos = player.EyePosition;
int numConePoints = 60;
// TODO: don't new[] every frame.
VertexPositionColor[] conePoints = new VertexPositionColor[numConePoints];
float visionRange = 150;
float visionRangeSq = visionRange * visionRange;
float fov = FMath.DegToRad(120);
float fovStep = fov / (numConePoints - 1);
Vector2 ray = new Vector2(visionRange * player.GetFacing, 0);
if (player.GetPose == Player.Pose.Stretching) {
ray = ray.Rotate(player.GetFacing * FMath.DegToRad(-30));
}
if (player.GetPose == Player.Pose.Crouching) {
ray = ray.Rotate(player.GetFacing * FMath.DegToRad(30));
}
for (int i = 0; i < conePoints.Length; i++) {
float angle = -fov / 2 + fovStep * i;
Vector2 rotated = ray.Rotate(angle);
Vector2 closestHit = Vector2.Add(eyePos, rotated);
float hitTime = 1f;
Vector2 halfTileSize = new Vector2(World.TileSize / 2.0f, World.TileSize / 2.0f);
for (int j = 0; j < world.CollisionTargets.Length; j++) {
AABB box = world.CollisionTargets[j];
if (Math.Abs(box.Position.X - player.Position.X) > visionRange + halfTileSize.X) {
continue;
}
Vector2 delta = Vector2.Add(halfTileSize, Vector2.Subtract(box.Position, eyePos));
if (delta.LengthSquared() > visionRangeSq) {
continue;
}
Hit? maybeHit = box.IntersectSegment(eyePos, rotated);
if (maybeHit != null) {
Hit hit = maybeHit.Value;
if (hit.Time < hitTime) {
hitTime = hit.Time;
closestHit = hit.Position;
}
}
}
float tint = 0.6f - hitTime / 2;
Color tinted = Color.FromNonPremultiplied(new Vector4(0, 0, 1, tint));
conePoints[i] = new VertexPositionColor(new Vector3(closestHit, 0), tinted);
}
// TODO: don't new[] every frame.
VertexPositionColor[] vertices = new VertexPositionColor[numConePoints * 3];
VertexPositionColor eyeVertex = new VertexPositionColor(new Vector3(eyePos, 0), color);
for (int i = 0; i < numConePoints - 1; i++) {
vertices[i * 3] = eyeVertex;
vertices[i * 3 + 1] = conePoints[i];
vertices[i * 3 + 2] = conePoints[i + 1];
}
VertexBuffer vertexBuffer = new VertexBuffer(
GraphicsDevice, typeof(VertexPositionColor), vertices.Length, BufferUsage.WriteOnly);
vertexBuffer.SetData<VertexPositionColor>(vertices);
GraphicsDevice.SetVertexBuffer(vertexBuffer);
foreach (EffectPass pass in lightingEffect.CurrentTechnique.Passes) {
pass.Apply();
GraphicsDevice.DrawPrimitives(PrimitiveType.TriangleList, 0, vertices.Length / 3);
}
}
}
}