sneak/Shared/Scene.cs
Colin McMillen 05638483a4 Support 4-layer parallax-scrolling backgrounds.
GitOrigin-RevId: 58c1d1fee99e56dd656af5bbf628fbdc16d55e14
2020-02-19 13:07:58 -05:00

119 lines
4.1 KiB
C#

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.Graphics;
namespace SemiColinGames {
class Scene {
public bool Enabled = false;
Color backgroundColor = Color.CornflowerBlue;
readonly GraphicsDevice graphics;
readonly Camera camera;
readonly RenderTarget2D sceneTarget;
readonly RenderTarget2D lightingTarget;
readonly BasicEffect lightingEffect;
readonly SpriteBatch spriteBatch;
public Scene(GraphicsDevice graphics, Camera camera) {
this.graphics = graphics;
this.camera = camera;
sceneTarget = new RenderTarget2D(
graphics, camera.Width, camera.Height, false /* mipmap */,
graphics.PresentationParameters.BackBufferFormat, DepthFormat.Depth24);
lightingTarget = new RenderTarget2D(
graphics, camera.Width, camera.Height, false /* mipmap */,
graphics.PresentationParameters.BackBufferFormat, DepthFormat.Depth24);
lightingEffect = new BasicEffect(graphics) {
World = Matrix.CreateTranslation(0, 0, 0),
View = Matrix.CreateLookAt(Vector3.Backward, Vector3.Zero, Vector3.Up),
VertexColorEnabled = true
};
spriteBatch = new SpriteBatch(graphics);
}
public void Draw(World world, Player player, LinesOfSight linesOfSight) {
graphics.SetRenderTarget(null);
graphics.Clear(backgroundColor);
if (!Enabled) {
return;
}
graphics.SetRenderTarget(sceneTarget);
graphics.Clear(backgroundColor);
// Draw scene to sceneTarget.
spriteBatch.Begin(SpriteSortMode.Deferred, null, SamplerState.LinearWrap, null, null);
// Draw background.
// We assume that all backgrounds are the same size; if not, the computation of yOffset needs
// to be computed separately for every background.
int yOffset = Textures.Background1.Height - camera.Height - 64;
Color bgBlend = Color.FromNonPremultiplied(new Vector4(1, 1, 1, 1));
Rectangle bgTarget = new Rectangle(0, 0, camera.Width, camera.Height);
Rectangle bgSource = new Rectangle(
(int) (camera.Left * 1f / 16), yOffset, camera.Width, camera.Height);
spriteBatch.Draw(Textures.Background1, bgTarget, bgSource, bgBlend);
bgSource = new Rectangle(
(int) (camera.Left * 1f / 8), yOffset, camera.Width, camera.Height);
spriteBatch.Draw(Textures.Background2, bgTarget, bgSource, bgBlend);
bgSource = new Rectangle(
(int) (camera.Left * 1f / 4), yOffset, camera.Width, camera.Height);
spriteBatch.Draw(Textures.Background3, bgTarget, bgSource, bgBlend);
bgSource = new Rectangle(
(int) (camera.Left * 1f / 2), yOffset, camera.Width, camera.Height);
spriteBatch.Draw(Textures.Background4, bgTarget, bgSource, bgBlend);
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);
// Aaaaand we're done.
spriteBatch.End();
// Draw lighting to lightingTarget.
graphics.SetRenderTarget(lightingTarget);
graphics.Clear(new Color(0, 0, 0, 0f));
lightingEffect.Projection = camera.Projection;
linesOfSight.Draw(player, world.CollisionTargets, graphics, lightingEffect);
// Draw debug rects & lines on top.
Debug.Draw(graphics, lightingEffect);
// Draw sceneTarget to screen.
graphics.SetRenderTarget(null);
spriteBatch.Begin(SpriteSortMode.Immediate, BlendState.AlphaBlend,
SamplerState.PointClamp, DepthStencilState.Default,
RasterizerState.CullNone);
Rectangle drawRect = new Rectangle(
0, 0, graphics.Viewport.Width, graphics.Viewport.Height);
spriteBatch.Draw(sceneTarget, drawRect, Color.White);
spriteBatch.Draw(lightingTarget, drawRect, Color.White);
// Draw debug toasts.
Debug.DrawToasts(spriteBatch);
spriteBatch.End();
}
}
}