Use hsl instead of hsv for brightness and color effects

Revert "Increase maximum texture size and back it off if GL fails to render"

package.json

@@ -53,7 +53,7 @@
     "minilog": "3.1.0",
     "raw-loader": "^0.5.1",
     "scratch-storage": "^1.0.0",
-    "scratch-svg-renderer": "0.2.0-prerelease.20181126212715",
+    "scratch-svg-renderer": "0.2.0-prerelease.20181220183040",
     "twgl.js": "4.4.0"
   }
 }

src/Drawable.js

@@ -426,16 +426,16 @@ class Drawable {
      * Should the drawable use NEAREST NEIGHBOR or LINEAR INTERPOLATION mode
      */
     get useNearest () {
-        // We can't use nearest neighbor unless we are a multiple of 90 rotation
-        if (this._direction % 90 !== 0) {
-            return false;
-        }
-
         // Raster skins (bitmaps) should always prefer nearest neighbor
         if (this.skin.isRaster) {
             return true;
         }
 
+        // We can't use nearest neighbor unless we are a multiple of 90 rotation
+        if (this._direction % 90 !== 0) {
+            return false;
+        }
+
         // If the scale of the skin is very close to 100 (0.99999 variance is okay I guess)
         if (Math.abs(this.scale[0]) > 99 && Math.abs(this.scale[0]) < 101 &&
             Math.abs(this.scale[1]) > 99 && Math.abs(this.scale[1]) < 101) {
@@ -536,13 +536,15 @@ class Drawable {
     _getTransformedHullPoints () {
         const projection = twgl.m4.ortho(-1, 1, -1, 1, -1, 1);
         const skinSize = this.skin.size;
+        const halfXPixel = 1 / skinSize[0] / 2;
+        const halfYPixel = 1 / skinSize[1] / 2;
         const tm = twgl.m4.multiply(this._uniforms.u_modelMatrix, projection);
         const transformedHullPoints = [];
         for (let i = 0; i < this._convexHullPoints.length; i++) {
             const point = this._convexHullPoints[i];
             const glPoint = twgl.v3.create(
-                0.5 + (-point[0] / skinSize[0]),
-                (point[1] / skinSize[1]) - 0.5,
+                0.5 + (-point[0] / skinSize[0]) - halfXPixel,
+                (point[1] / skinSize[1]) - 0.5 + halfYPixel,
                 0
             );
             twgl.m4.transformPoint(tm, glPoint, glPoint);

src/RenderWebGL.js

@@ -931,7 +931,11 @@ class RenderWebGL extends EventEmitter {
         const worldPos = twgl.v3.create();
 
         drawable.updateMatrix();
-        drawable.skin.updateSilhouette();
+        if (drawable.skin) {
+            drawable.skin.updateSilhouette();
+        } else {
+            log.warn(`Could not find skin for drawable with id: ${drawableID}`);
+        }
 
         for (worldPos[1] = bounds.bottom; worldPos[1] <= bounds.top; worldPos[1]++) {
             for (worldPos[0] = bounds.left; worldPos[0] <= bounds.right; worldPos[0]++) {
@@ -963,7 +967,11 @@ class RenderWebGL extends EventEmitter {
             // default pick list ignores visible and ghosted sprites.
             if (drawable.getVisible() && drawable.getUniforms().u_ghost !== 0) {
                 drawable.updateMatrix();
-                drawable.skin.updateSilhouette();
+                if (drawable.skin) {
+                    drawable.skin.updateSilhouette();
+                } else {
+                    log.warn(`Could not find skin for drawable with id: ${id}`);
+                }
                 return true;
             }
             return false;

src/shaders/sprite.frag

@@ -54,39 +54,24 @@ varying vec2 v_texCoord;
 // Smaller values can cause problems with "color" and "brightness" effects on some mobile devices
 const float epsilon = 1e-3;
 
-// Convert an RGB color to Hue, Saturation, and Value.
+// Convert an RGB color to Hue, Chroma, and Value.
 // All components of input and output are expected to be in the [0,1] range.
-vec3 convertRGB2HSV(vec3 rgb)
+vec3 convertRGB2HCV(vec3 rgb)
 {
-	// Hue calculation has 3 cases, depending on which RGB component is largest, and one of those cases involves a "mod"
-	// operation. In order to avoid that "mod" we split the M==R case in two: one for G<B and one for B>G. The B>G case
-	// will be calculated in the negative and fed through abs() in the hue calculation at the end.
-	// See also: https://en.wikipedia.org/wiki/HSL_and_HSV#Hue_and_chroma
-	const vec4 hueOffsets = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
+	// Based on work by Sam Hocevar and Emil Persson
+	vec4 P = (rgb.g < rgb.b) ? vec4(rgb.bg, -1.0, 2.0/3.0) : vec4(rgb.gb, 0.0, -1.0/3.0);
+	vec4 Q = (rgb.r < P.x) ? vec4(P.xyw, rgb.r) : vec4(rgb.r, P.yzx);
+	float C = Q.x - min(Q.w, Q.y);
+	float H = abs((Q.w - Q.y) / (6.0 * C + epsilon) + Q.z);
+	return vec3(H, C, Q.x);
+}
 
-	// temp1.xy = sort B & G (largest first)
-	// temp1.z = the hue offset we'll use if it turns out that R is the largest component (M==R)
-	// temp1.w = the hue offset we'll use if it turns out that R is not the largest component (M==G or M==B)
-	vec4 temp1 = rgb.b > rgb.g ? vec4(rgb.bg, hueOffsets.wz) : vec4(rgb.gb, hueOffsets.xy);
-
-	// temp2.x = the largest component of RGB ("M" / "Max")
-	// temp2.yw = the smaller components of RGB, ordered for the hue calculation (not necessarily sorted by magnitude!)
-	// temp2.z = the hue offset we'll use in the hue calculation
-	vec4 temp2 = rgb.r > temp1.x ? vec4(rgb.r, temp1.yzx) : vec4(temp1.xyw, rgb.r);
-
-	// m = the smallest component of RGB ("min")
-	float m = min(temp2.y, temp2.w);
-
-	// Chroma = M - m
-	float C = temp2.x - m;
-
-	// Value = M
-	float V = temp2.x;
-
-	return vec3(
-		abs(temp2.z + (temp2.w - temp2.y) / (6.0 * C + epsilon)), // Hue
-		C / (temp2.x + epsilon), // Saturation
-		V); // Value
+vec3 convertRGB2HSL(vec3 rgb)
+{
+	vec3 hcv = convertRGB2HCV(rgb);
+	float L = hcv.z - hcv.y * 0.5;
+	float S = hcv.y / (1.0 - abs(L * 2.0 - 1.0) + epsilon);
+	return vec3(hcv.x, S, L);
 }
 
 vec3 convertHue2RGB(float hue)
@@ -97,11 +82,11 @@ vec3 convertHue2RGB(float hue)
 	return clamp(vec3(r, g, b), 0.0, 1.0);
 }
 
-vec3 convertHSV2RGB(vec3 hsv)
+vec3 convertHSL2RGB(vec3 hsl)
 {
-	vec3 rgb = convertHue2RGB(hsv.x);
-	float c = hsv.z * hsv.y;
-	return rgb * c + hsv.z - c;
+	vec3 rgb = convertHue2RGB(hsl.x);
+	float C = (1.0 - abs(2.0 * hsl.z - 1.0)) * hsl.y;
+	return (rgb - 0.5) * C + hsl.z;
 }
 #endif // !defined(DRAW_MODE_silhouette) && (defined(ENABLE_color) || defined(ENABLE_brightness))
 
@@ -166,7 +151,7 @@ void main()
 
 	#if defined(ENABLE_color) || defined(ENABLE_brightness)
 	{
-		vec3 hsv = convertRGB2HSV(gl_FragColor.xyz);
+		vec3 hsl = convertRGB2HSL(gl_FragColor.xyz);
 
 		#ifdef ENABLE_color
 		{
@@ -174,19 +159,19 @@ void main()
 			// so that some slight change of hue will be visible
 			const float minLightness = 0.11 / 2.0;
 			const float minSaturation = 0.09;
-			if (hsv.z < minLightness) hsv = vec3(0.0, 1.0, minLightness);
-			else if (hsv.y < minSaturation) hsv = vec3(0.0, minSaturation, hsv.z);
+			if (hsl.z < minLightness) hsl = vec3(0.0, 1.0, minLightness);
+			else if (hsl.y < minSaturation) hsl = vec3(0.0, minSaturation, hsl.z);
 
-			hsv.x = mod(hsv.x + u_color, 1.0);
-			if (hsv.x < 0.0) hsv.x += 1.0;
+			hsl.x = mod(hsl.x + u_color, 1.0);
+			if (hsl.x < 0.0) hsl.x += 1.0;
 		}
 		#endif // ENABLE_color
 
 		#ifdef ENABLE_brightness
-		hsv.z = clamp(hsv.z + u_brightness, 0.0, 1.0);
+		hsl.z = clamp(hsl.z + u_brightness, 0.0, 1.0);
 		#endif // ENABLE_brightness
 
-		gl_FragColor.rgb = convertHSV2RGB(hsv);
+		gl_FragColor.rgb = convertHSL2RGB(hsl);
 	}
 	#endif // defined(ENABLE_color) || defined(ENABLE_brightness)