Merge pull request #816 from OpenGeoscience/image-test-stability

Modify the webgl line feature shaders.

.travis.yml

@@ -5,7 +5,7 @@ sudo: required
 dist: trusty
 
 node_js:
-  - 6
+  - 8
 
 addons:
   firefox: latest  # version 55.0 - 57.x have an issue with screenshots.
@@ -38,8 +38,9 @@ before_install:
   # Start xvfb with a specific resolution and pixel depth
   - "/sbin/start-stop-daemon --start --quiet --pidfile /tmp/custom_xvfb_99.pid --make-pidfile --background --exec /usr/bin/Xvfb -- :99 -ac -screen 0 1280x1024x24"
   - CACHE="${HOME}/cache" CMAKE_VERSION=3.5.0 CMAKE_SHORT_VERSION=3.5 source ./scripts/install_cmake.sh
+  - npm install -g npm@latest
+  - npm install -g node-pre-gyp
   - npm prune
-  - npm install -g npm
 
 before_script:
   - export DISPLAY=:99.0

docs/provisioning.rst

@@ -15,7 +15,7 @@ onward.  They assume a basic installation, as, for instance, from the
 
 Add nodejs to the sources so it can be installed ::
 
-    wget -qO- https://deb.nodesource.com/setup_6.x | sudo bash -
+    wget -qO- https://deb.nodesource.com/setup_8.x | sudo bash -
 
 Install required packages (you may want to also include cmake-curses-gui for
 convenience in configuring CMake options) ::

src/gl/lineFeature.js

@@ -109,17 +109,24 @@ var gl_lineFeature = function (arg) {
           'const float PI = 3.14159265358979323846264;',
 
           'vec4 viewCoord(vec3 c) {',
-          '  vec4 result = projectionMatrix * modelViewMatrix * vec4(c.xyz, 1);',
+          '  vec4 result = projectionMatrix * modelViewMatrix * vec4(c.xyz, 1.0);',
           '  if (result.w != 0.0)  result = result / result.w;',
           '  return result;',
           '}',
 
+          'float atan2(float y, float x) {',
+          '  if (x > 0.0)  return atan(y / x);',
+          '  if (x < 0.0 && y >= 0.0)  return atan(y / x) + PI;',
+          '  if (x < 0.0)  return atan(y / x) - PI;',
+          '  return sign(y) * 0.5 * PI;',
+          '}',
+
           'void main(void)',
           '{',
           /* If any vertex has been deliberately set to a negative opacity,
            * skip doing computations on it. */
           '  if (strokeOpacity < 0.0) {',
-          '    gl_Position = vec4(2, 2, 0, 1);',
+          '    gl_Position = vec4(2.0, 2.0, 0.0, 1.0);',
           '    return;',
           '  }',
           /* convert coordinates.  We have four values, since we need to
@@ -133,10 +140,10 @@ var gl_lineFeature = function (arg) {
           // calculate line segment vector and angle
           '  vec2 deltaCB = C.xy - B.xy;',
           '  if (deltaCB == vec2(0.0, 0.0)) {',
-          '    gl_Position = vec4(2, 2, 0, 1);',
+          '    gl_Position = vec4(2.0, 2.0, 0.0, 1.0);',
           '    return;',
           '  }',
-          '  float angleCB = atan(deltaCB.y / aspect, deltaCB.x);',
+          '  float angleCB = atan2(deltaCB.y, deltaCB.x * aspect);',
           // values we need to pass along
           '  strokeColorVar = vec4(strokeColor, strokeOpacity);',
           // extract values from our flags field
@@ -169,22 +176,22 @@ var gl_lineFeature = function (arg) {
           // offset, then the functional join angle is not simply half the
           // angle between the two lines, but rather half the angle of the
           // inside edge of the the two lines.
-          '  float cosABC, sinABC, cosBCD, sinBCD;',  // of half angles
+          '  float cosABC = 1.0, sinABC = 0.0, cosBCD = 1.0, sinBCD = 0.0;',  // of half angles
           // handle near end
           '  if (nearMode >= 4) {',
-          '    float angleBA = atan((B.y - A.y) / aspect, B.x - A.x);',
+          '    float angleBA = atan2(B.y - A.y, (B.x - A.x) * aspect);',
           '    if (A.xy == B.xy)  angleBA = angleCB;',
           '    float angleABC = angleCB - angleBA;',
           // ensure angle is in the range [-PI, PI], then take the half angle
-          '    angleABC = (mod(angleABC + PI, 2.0 * PI) - PI) / 2.0;',
+          '    angleABC = (mod(angleABC + 3.0 * PI, 2.0 * PI) - PI) / 2.0;',
           '    cosABC = cos(angleABC);  sinABC = sin(angleABC);',
           // if this angle is close to flat, pass-through the join
           '    if (nearMode >= 4 && cosABC > 0.999999) {',
           '      nearMode = 3;',
           '    }',
           // miter, miter-clip
           '    if (nearMode == 4 || nearMode == 7) {',
-          '      if (cosABC == 0.0 || 1.0 / cosABC > miterLimit) {',
+          '      if (cosABC < 0.000001 || 1.0 / cosABC > miterLimit) {',
           '        if (nearMode == 4) {',
           '          nearMode = 5;',
           '        } else {',
@@ -205,19 +212,19 @@ var gl_lineFeature = function (arg) {
 
           // handle far end
           '  if (farMode >= 4) {',
-          '    float angleDC = atan((D.y - C.y) / aspect, D.x - C.x);',
+          '    float angleDC = atan2(D.y - C.y, (D.x - C.x) * aspect);',
           '    if (D.xy == C.xy)  angleDC = angleCB;',
           '    float angleBCD = angleDC - angleCB;',
           // ensure angle is in the range [-PI, PI], then take the half angle
-          '    angleBCD = (mod(angleBCD + PI, 2.0 * PI) - PI) / 2.0;',
+          '    angleBCD = (mod(angleBCD + 3.0 * PI, 2.0 * PI) - PI) / 2.0;',
           '    cosBCD = cos(angleBCD);  sinBCD = sin(angleBCD);',
           // if this angle is close to flat, pass-through the join
           '    if (farMode >= 4 && cosBCD > 0.999999) {',
           '      farMode = 3;',
           '    }',
           // miter, miter-clip
           '    if (farMode == 4 || farMode == 7) {',
-          '      if (cosBCD == 0.0 || 1.0 / cosBCD > miterLimit) {',
+          '      if (cosBCD < 0.000001 || 1.0 / cosBCD > miterLimit) {',
           '        if (farMode == 4)  farMode = 5;',
           '      } else {',
           '        farMode = 4;',
@@ -231,7 +238,7 @@ var gl_lineFeature = function (arg) {
           '  gl_Position = vec4(',
           '    B.x + (xOffset * cos(angleCB) - yOffset * sin(angleCB)) * pixelWidth,',
           '    B.y + (xOffset * sin(angleCB) + yOffset * cos(angleCB)) * pixelWidth * aspect,',
-          '    B.z, 1);',
+          '    B.z, 1.0);',
           // store other values needed to determine which pixels to plot.
           '  float lineLength = length(vec2(deltaCB.x, deltaCB.y / aspect)) / pixelWidth;',
 
@@ -262,7 +269,11 @@ var gl_lineFeature = function (arg) {
   function createFragmentShader(allowDebug) {
     var fragmentShaderSource = [
           '#ifdef GL_ES',
-          '  precision highp float;',
+          '  #ifdef GL_FRAGMENT_PRECISION_HIGH',
+          '    precision highp float;',
+          '  #else',
+          '    precision mediump float;',
+          '  #endif',
           '#endif',
           'varying vec4 strokeColorVar;',
           'varying vec4 subpos;',
@@ -275,8 +286,8 @@ var gl_lineFeature = function (arg) {
           '  vec4 color = strokeColorVar;',
           allowDebug ? '  bool debug = bool(mod(fixedFlags, 2.0));' : '',
           '  float opacity = 1.0;',
-          '  int nearMode = int(info.x);',
-          '  int farMode = int(info.y);',
+          '  int nearMode = int(floor(info.x + 0.5));',
+          '  int farMode = int(floor(info.y + 0.5));',
           '  float cosABC = angles.x;',
           '  float sinABC = angles.y;',
           '  float cosBCD = angles.z;',

testing/test-data/base-images.tgz.md5

@@ -1 +1 @@
-2333a69e96ce063d10862bd8d563eb3d
+24a2ffe0807138fe13c33ddeccb2b426

testing/test-data/base-images.tgz.url

@@ -1 +1 @@
-https://data.kitware.com/api/v1/file/5a9ed5838d777f0685786207/download
+https://data.kitware.com/api/v1/file/5af1fcff8d777f0685797d19/download

tests/gl-cases/glPolygons.js

@@ -2446,9 +2446,7 @@ describe('glPolygons', function () {
       layer: layer
     }).read(JSON.stringify(data), function () {
       myMap.draw();
-      // maximum error is 0.0030 because of a change in Chrome 65.  When new
-      // versions are released, see if this can be moved back to 0.0015
-      imageTest.imageTest('glMultiPolygons', null, 0.0030, done, myMap.onIdle, 0, 2);
+      imageTest.imageTest('glMultiPolygons', null, 0.0015, done, myMap.onIdle, 0, 2);
     });
   });
 

tests/headed-cases/lines.js

@@ -16,9 +16,7 @@ describe('lines example', function () {
   it('more lines', function (done) {
     base$ = $('iframe#map')[0].contentWindow.jQuery;
     base$('#lines').val(100000).trigger('change');
-    // maximum error is 0.0030 because of a change in Chrome 65.  When new
-    // versions are released, see if this can be moved back to 0.0015
-    imageTest.imageTest('exampleLines100k', '#map', 0.0030, done, null, 0, 2, '#map.ready[segments="100000"]');
+    imageTest.imageTest('exampleLines100k', '#map', 0.0015, done, null, 0, 2, '#map.ready[segments="100000"]');
   }, 10000);
   it('thin preset', function (done) {
     base$('button.preset').eq(1).trigger('click');