From 4ef6922da8a4dd03c86615fca0d716d3c7ef3ca7 Mon Sep 17 00:00:00 2001
From: schmelczerandras <andras@schmelzer.dev>
Date: Sat, 25 Jul 2020 17:02:08 +0200
Subject: [PATCH] Add naive quality controller

---
 .../src/scripts/drawing/webgl2-renderer.ts    | 71 +++++++++++++++++--
 frontend/src/shaders/random.frag              |  1 -
 2 files changed, 67 insertions(+), 5 deletions(-)

diff --git a/frontend/src/scripts/drawing/webgl2-renderer.ts b/frontend/src/scripts/drawing/webgl2-renderer.ts
index da179c6..c3e4512 100644
--- a/frontend/src/scripts/drawing/webgl2-renderer.ts
+++ b/frontend/src/scripts/drawing/webgl2-renderer.ts
@@ -1,5 +1,7 @@
 import { mat2d, vec2 } from 'gl-matrix';
+import { clamp } from '../helper/clamp';
 import { Rectangle } from '../math/rectangle';
+import { InfoText } from '../objects/types/info-text';
 import { Drawer } from './drawer';
 import { DefaultFrameBuffer } from './graphics-library/default-frame-buffer';
 import { FragmentShaderOnlyProgram } from './graphics-library/fragment-shader-only-program';
@@ -16,6 +18,67 @@ export class WebGl2Renderer implements Drawer {
   private distanceFieldFrameBuffer: IntermediateFrameBuffer;
   private lightingFrameBuffer: DefaultFrameBuffer;
 
+  private targetDeltaTime = (1 / 50) * 1000;
+  private deltaTimeError = (1 / 1000) * 1000;
+  private additiveQualityIncrease = 0.05;
+  private multiplicativeQualityDecrease = 1.5;
+  private timeSinceLastAdjusment = 0;
+  private adjusmentRate = 500;
+  private maxRenderScale = 2;
+  private minRenderScale = 0.2;
+
+  private exponentialDecayedDeltaTime = 0.0;
+
+  private configureRenderScale(deltaTime: DOMHighResTimeStamp) {
+    this.timeSinceLastAdjusment += deltaTime;
+    if (this.timeSinceLastAdjusment < this.adjusmentRate) {
+      return;
+    }
+    this.timeSinceLastAdjusment = 0;
+
+    this.exponentialDecayedDeltaTime =
+      (15 / 16) * this.exponentialDecayedDeltaTime + deltaTime / 16;
+
+    if (
+      this.exponentialDecayedDeltaTime <=
+      this.targetDeltaTime - this.deltaTimeError
+    ) {
+      this.distanceFieldFrameBuffer.renderScale +=
+        this.additiveQualityIncrease / 2;
+      this.lightingFrameBuffer.renderScale += this.additiveQualityIncrease;
+    } else if (
+      this.exponentialDecayedDeltaTime >
+      this.targetDeltaTime + this.deltaTimeError
+    ) {
+      this.distanceFieldFrameBuffer.renderScale /= this.multiplicativeQualityDecrease;
+      this.lightingFrameBuffer.renderScale /= this.multiplicativeQualityDecrease;
+    }
+
+    this.distanceFieldFrameBuffer.renderScale = clamp(
+      this.distanceFieldFrameBuffer.renderScale,
+      this.minRenderScale,
+      this.maxRenderScale
+    );
+    this.lightingFrameBuffer.renderScale = clamp(
+      this.lightingFrameBuffer.renderScale,
+      this.minRenderScale,
+      this.maxRenderScale
+    );
+
+    InfoText.modifyRecord(
+      'dt decay',
+      this.exponentialDecayedDeltaTime.toFixed(2)
+    );
+    InfoText.modifyRecord(
+      'q1',
+      this.distanceFieldFrameBuffer.renderScale.toFixed(2)
+    );
+    InfoText.modifyRecord(
+      'q2',
+      this.lightingFrameBuffer.renderScale.toFixed(2)
+    );
+  }
+
   constructor(
     private canvas: HTMLCanvasElement,
     private overlay: HTMLElement,
@@ -34,8 +97,8 @@ export class WebGl2Renderer implements Drawer {
       new FragmentShaderOnlyProgram(this.gl, ...shaderSources[1]),
     ]);
 
-    this.distanceFieldFrameBuffer.renderScale = 0.1;
-    this.lightingFrameBuffer.renderScale = 0.2;
+    this.distanceFieldFrameBuffer.renderScale = 0.5;
+    this.lightingFrameBuffer.renderScale = 1;
 
     try {
       this.stopwatch = new WebGlStopwatch(this.gl);
@@ -43,6 +106,8 @@ export class WebGl2Renderer implements Drawer {
   }
 
   public startFrame(deltaTime: DOMHighResTimeStamp): void {
+    this.configureRenderScale(deltaTime);
+
     this.stopwatch?.start();
     this.uniforms = {};
     this.distanceFieldFrameBuffer.setSize();
@@ -62,8 +127,6 @@ export class WebGl2Renderer implements Drawer {
   }
 
   private calculateOwnUniforms() {
-    const resolution = vec2.fromValues(this.canvas.width, this.canvas.height);
-
     const distanceScreenToWorld = this.getScreenToWorldTransform(
       this.distanceFieldFrameBuffer.getSize()
     );
diff --git a/frontend/src/shaders/random.frag b/frontend/src/shaders/random.frag
index d8f0df9..56ce0b4 100644
--- a/frontend/src/shaders/random.frag
+++ b/frontend/src/shaders/random.frag
@@ -10,7 +10,6 @@ float interpolate(float from, float to, float quotient) {
     return from + (to - from) * clamp(steppedQ, 0.0, 1.0);
 }
 
-
 float noise(float x){
     return fract(sin(x) * 43758.5453123);
 }