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authorPushkar Joshi2012-03-02 12:23:44 -0800
committerPushkar Joshi2012-03-02 12:23:44 -0800
commit1b68bb87c458877cb850a96d8a093d6064bc41dc (patch)
treee479c2f0a3958cdf2110654b1886769518b1bee7 /js/helper-classes/RDGE
parent0b7f2f54738d2c1ea480b9bac7d3a750b1ef4df6 (diff)
downloadninja-1b68bb87c458877cb850a96d8a093d6064bc41dc.tar.gz
Catmull-Rom spline sampling for the brush stroke, and options for stroke size, stroke hardness and both stroke colors (left and right --- temporarily using the stroke and fill colors respectively)
Diffstat (limited to 'js/helper-classes/RDGE')
-rwxr-xr-xjs/helper-classes/RDGE/GLBrushStroke.js72
1 files changed, 66 insertions, 6 deletions
diff --git a/js/helper-classes/RDGE/GLBrushStroke.js b/js/helper-classes/RDGE/GLBrushStroke.js
index f5b0bce1..c1469977 100755
--- a/js/helper-classes/RDGE/GLBrushStroke.js
+++ b/js/helper-classes/RDGE/GLBrushStroke.js
@@ -31,6 +31,8 @@ function GLBrushStroke() {
31 //stroke information 31 //stroke information
32 this._strokeWidth = 0.0; 32 this._strokeWidth = 0.0;
33 this._strokeColor = [0.4, 0.4, 0.4, 1.0]; 33 this._strokeColor = [0.4, 0.4, 0.4, 1.0];
34 this._secondStrokeColor = this._strokeColor;
35 this._strokeHardness = 100;
34 this._strokeMaterial; 36 this._strokeMaterial;
35 this._strokeStyle = "Solid"; 37 this._strokeStyle = "Solid";
36 38
@@ -39,7 +41,7 @@ function GLBrushStroke() {
39 this._WETNESS_FACTOR = 0.25; 41 this._WETNESS_FACTOR = 0.25;
40 42
41 //prevent extremely long paths that can take a long time to render 43 //prevent extremely long paths that can take a long time to render
42 this._MAX_ALLOWED_SAMPLES = 500; 44 this._MAX_ALLOWED_SAMPLES = 5000;
43 45
44 //drawing context 46 //drawing context
45 this._world = null; 47 this._world = null;
@@ -106,6 +108,8 @@ function GLBrushStroke() {
106 this.setStrokeMaterial = function (m) { this._strokeMaterial = m; } 108 this.setStrokeMaterial = function (m) { this._strokeMaterial = m; }
107 this.getStrokeColor = function () { return this._strokeColor; } 109 this.getStrokeColor = function () { return this._strokeColor; }
108 this.setStrokeColor = function (c) { this._strokeColor = c; } 110 this.setStrokeColor = function (c) { this._strokeColor = c; }
111 this.setSecondStrokeColor = function(c){this._secondStrokeColor=c;}
112 this.setStrokeHardness = function(h){this._strokeHardness=h;}
109 this.getStrokeStyle = function () { return this._strokeStyle; } 113 this.getStrokeStyle = function () { return this._strokeStyle; }
110 this.setStrokeStyle = function (s) { this._strokeStyle = s; } 114 this.setStrokeStyle = function (s) { this._strokeStyle = s; }
111 115
@@ -133,7 +137,7 @@ function GLBrushStroke() {
133 this._Points[i][2]+=tz; 137 this._Points[i][2]+=tz;
134 } 138 }
135 } 139 }
136 140
137 this.computeMetaGeometry = function(){ 141 this.computeMetaGeometry = function(){
138 if (this._dirty){ 142 if (this._dirty){
139 var numPoints = this._Points.length; 143 var numPoints = this._Points.length;
@@ -172,6 +176,44 @@ function GLBrushStroke() {
172 } 176 }
173 } 177 }
174 178
179 //**** add samples to the long sections of the path --- Catmull-Rom spline interpolation
180 if (numPoints>1) {
181 var numInsertedPoints = 0;
182 var threshold = 5;//0.25*this._strokeWidth; //this determines whether a segment between two sample is too long
183 var prevPt = this._Points[0];
184 for (var i=1;i<numPoints;i++){
185 var pt = this._Points[i];
186 var diff = [pt[0]-prevPt[0], pt[1]-prevPt[1]];
187 var distance = Math.sqrt(diff[0]*diff[0]+diff[1]*diff[1]);
188 if (distance>threshold){
189 //build the control polygon for the Catmull-Rom spline (prev. 2 points and next 2 points)
190 var prev = (i===1) ? i-1 : i-2;
191 var next = (i===numPoints-1) ? i : i+1;
192 var ctrlPts = [this._Points[prev], this._Points[i-1], this._Points[i], this._Points[next]];
193 //insert points along the prev. to current point
194 var numNewPoints = Math.floor(distance/threshold);
195 for (var j=0;j<numNewPoints;j++){
196 var param = (j+1)/(numNewPoints+1);
197 var newpt = this._CatmullRomSplineInterpolate(ctrlPts, param);
198 //insert new point before point i
199 this._Points.splice(i, 0, newpt);
200 i++;
201 numInsertedPoints++;
202 }
203 this._dirty=true;
204 }
205 prevPt=pt;
206 //update numPoints to match the new length
207 numPoints = this._Points.length;
208
209 //end this function if the numPoints has gone above the max. size specified
210 if (numPoints> this._MAX_ALLOWED_SAMPLES){
211 console.log("leaving the resampling because numPoints is greater than limit:"+this._MAX_ALLOWED_SAMPLES);
212 break;
213 }
214 }
215 console.log("Inserted "+numInsertedPoints+" additional CatmullRom points");
216 }
175 // *** compute the bounding box ********* 217 // *** compute the bounding box *********
176 this._BBoxMin = [Infinity, Infinity, Infinity]; 218 this._BBoxMin = [Infinity, Infinity, Infinity];
177 this._BBoxMax = [-Infinity, -Infinity, -Infinity]; 219 this._BBoxMax = [-Infinity, -Infinity, -Infinity];
@@ -362,7 +404,6 @@ function GLBrushStroke() {
362 } 404 }
363 */ 405 */
364 406
365 //todo test how to render the path as a bunch of moveTo and lineTos (for calligraphic brush styles)
366 var numTraces = this._strokeWidth; 407 var numTraces = this._strokeWidth;
367 var halfNumTraces = numTraces/2; 408 var halfNumTraces = numTraces/2;
368 var deltaDisplacement = [1,0];//[this._strokeWidth/numTraces, 0]; //a horizontal line brush 409 var deltaDisplacement = [1,0];//[this._strokeWidth/numTraces, 0]; //a horizontal line brush
@@ -371,17 +412,20 @@ function GLBrushStroke() {
371 var disp = [startPos[0]+t*deltaDisplacement[0], startPos[1]+t*deltaDisplacement[1]]; 412 var disp = [startPos[0]+t*deltaDisplacement[0], startPos[1]+t*deltaDisplacement[1]];
372 //ctx.globalCompositeOperation = 'source-over'; 413 //ctx.globalCompositeOperation = 'source-over';
373 var distFromMiddle = Math.abs(halfNumTraces-t); 414 var distFromMiddle = Math.abs(halfNumTraces-t);
374 var alphaVal = 1.0 - (distFromMiddle/halfNumTraces); 415 var alphaVal = 1.0 - (100-this._strokeHardness)*(distFromMiddle/halfNumTraces)/100;
375 ctx.save(); 416 ctx.save();
376 ctx.lineWidth=this._strokeWidth/10;//4; 417 ctx.lineWidth=this._strokeWidth/10;//4;
377 if (ctx.lineWidth<2) 418 if (ctx.lineWidth<2)
378 ctx.lineWidth=2; 419 ctx.lineWidth=2;
420 if (t===numTraces-1){
421 ctx.lineWidth = 1;
422 }
379 ctx.lineJoin="bevel"; 423 ctx.lineJoin="bevel";
380 ctx.lineCap="butt"; 424 ctx.lineCap="butt";
381 if (t<numTraces/2) 425 if (t<numTraces/2)
382 ctx.strokeStyle="rgba("+parseInt(255*this._strokeColor[0])+","+parseInt(255*this._strokeColor[1])+","+parseInt(255*this._strokeColor[2])+","+alphaVal+")"; 426 ctx.strokeStyle="rgba("+parseInt(255*this._strokeColor[0])+","+parseInt(255*this._strokeColor[1])+","+parseInt(255*this._strokeColor[2])+","+alphaVal+")";
383 else 427 else
384 ctx.strokeStyle="rgba("+255+","+parseInt(255*this._strokeColor[1])+","+parseInt(255*this._strokeColor[2])+","+alphaVal+")"; 428 ctx.strokeStyle="rgba("+parseInt(255*this._secondStrokeColor[0])+","+parseInt(255*this._secondStrokeColor[1])+","+parseInt(255*this._secondStrokeColor[2])+","+alphaVal+")";
385 ctx.translate(disp[0],disp[1]); 429 ctx.translate(disp[0],disp[1]);
386 ctx.beginPath(); 430 ctx.beginPath();
387 ctx.moveTo(this._Points[0][0]-bboxMin[0], this._Points[0][1]-bboxMin[1]); 431 ctx.moveTo(this._Points[0][0]-bboxMin[0], this._Points[0][1]-bboxMin[1]);
@@ -437,4 +481,20 @@ function GLBrushStroke() {
437 return true; 481 return true;
438 } 482 }
439 483
440} //function GLSubpath ...class definition \ No newline at end of file 484} //function GLBrushStroke ...class definition
485
486GLBrushStroke.prototype._CatmullRomSplineInterpolate = function(ctrlPts, t)
487{
488 //perform CatmullRom interpolation on the spline...assume t is in [0,1]
489 var t2 = t*t;
490 var t3 = t2*t;
491 var retPoint = [0,0,0];
492 for (var i=0;i<3;i++){
493 retPoint[i] = 0.5 *(
494 (2*ctrlPts[1][i]) +
495 (-ctrlPts[0][i] + ctrlPts[2][i]) * t +
496 (2*ctrlPts[0][i] - 5*ctrlPts[1][i] + 4*ctrlPts[2][i] - ctrlPts[3][i]) * t2 +
497 (-ctrlPts[0][i] + 3*ctrlPts[1][i]- 3*ctrlPts[2][i] + ctrlPts[3][i]) * t3);
498 }
499 return retPoint;
500} \ No newline at end of file