Webgl / added time and resolution as default uniforms

Also added the `zoom` and `resolution` style operators

src/ol/style/expressions.js

@@ -314,6 +314,24 @@ Operators['time'] = {
     return 'u_time';
   }
 };
+Operators['zoom'] = {
+  getReturnType: function(args) {
+    return ValueTypes.NUMBER;
+  },
+  toGlsl: function(context, args) {
+    assertArgsCount(args, 0);
+    return 'u_zoom';
+  }
+};
+Operators['resolution'] = {
+  getReturnType: function(args) {
+    return ValueTypes.NUMBER;
+  },
+  toGlsl: function(context, args) {
+    assertArgsCount(args, 0);
+    return 'u_resolution';
+  }
+};
 Operators['*'] = {
   getReturnType: function(args) {
     return ValueTypes.NUMBER;

src/ol/webgl/Helper.js

@@ -43,7 +43,9 @@ export const DefaultUniform = {
   PROJECTION_MATRIX: 'u_projectionMatrix',
   OFFSET_SCALE_MATRIX: 'u_offsetScaleMatrix',
   OFFSET_ROTATION_MATRIX: 'u_offsetRotateMatrix',
-  TIME: 'u_time'
+  TIME: 'u_time',
+  ZOOM: 'u_zoom',
+  RESOLUTION: 'u_resolution'
 };
 
 /**
@@ -557,6 +559,8 @@ class WebGLHelper extends Disposable {
     this.setUniformMatrixValue(DefaultUniform.OFFSET_ROTATION_MATRIX, fromTransform(this.tmpMat4_, offsetRotateMatrix));
 
     this.setUniformFloatValue(DefaultUniform.TIME, (Date.now() - this.startTime_) * 0.001);
+    this.setUniformFloatValue(DefaultUniform.ZOOM, frameState.viewState.zoom);
+    this.setUniformFloatValue(DefaultUniform.RESOLUTION, frameState.viewState.resolution);
   }
 
   /**

src/ol/webgl/ShaderBuilder.js

@@ -274,6 +274,8 @@ uniform mat4 u_projectionMatrix;
 uniform mat4 u_offsetScaleMatrix;
 uniform mat4 u_offsetRotateMatrix;
 uniform float u_time;
+uniform float u_zoom;
+uniform float u_resolution;
 ${this.uniforms.map(function(uniform) {
     return 'uniform ' + uniform + ';';
   }).join('\n')}
@@ -335,6 +337,8 @@ ${varyings.map(function(varying) {
 
     return `precision mediump float;
 uniform float u_time;
+uniform float u_zoom;
+uniform float u_resolution;
 ${this.uniforms.map(function(uniform) {
     return 'uniform ' + uniform + ';';
   }).join('\n')}

test/spec/ol/style/expressions.test.js

@@ -122,6 +122,8 @@ describe('ol.style.expressions', function() {
       expect(getValueType(['get', 'myAttr'])).to.eql(ValueTypes.ANY);
       expect(getValueType(['var', 'myValue'])).to.eql(ValueTypes.ANY);
       expect(getValueType(['time'])).to.eql(ValueTypes.NUMBER);
+      expect(getValueType(['zoom'])).to.eql(ValueTypes.NUMBER);
+      expect(getValueType(['resolution'])).to.eql(ValueTypes.NUMBER);
       expect(getValueType(['+', ['get', 'size'], 12])).to.eql(ValueTypes.NUMBER);
       expect(getValueType(['-', ['get', 'size'], 12])).to.eql(ValueTypes.NUMBER);
       expect(getValueType(['/', ['get', 'size'], 12])).to.eql(ValueTypes.NUMBER);
@@ -156,6 +158,8 @@ describe('ol.style.expressions', function() {
       expect(expressionToGlsl(context, ['get', 'myAttr'])).to.eql('a_myAttr');
       expect(expressionToGlsl(context, ['var', 'myValue'])).to.eql('u_myValue');
       expect(expressionToGlsl(context, ['time'])).to.eql('u_time');
+      expect(expressionToGlsl(context, ['zoom'])).to.eql('u_zoom');
+      expect(expressionToGlsl(context, ['resolution'])).to.eql('u_resolution');
       expect(expressionToGlsl(context, ['+', ['*', ['get', 'size'], 0.001], 12])).to.eql('((a_size * 0.001) + 12.0)');
       expect(expressionToGlsl(context, ['/', ['-', ['get', 'size'], 20], 100])).to.eql('((a_size - 20.0) / 100.0)');
       expect(expressionToGlsl(context, ['clamp', ['get', 'attr2'], ['get', 'attr3'], 20])).to.eql('clamp(a_attr2, a_attr3, 20.0)');

test/spec/ol/webgl/helper.test.js

@@ -14,6 +14,8 @@ const VERTEX_SHADER = `
   uniform mat4 u_offsetScaleMatrix;
   uniform mat4 u_offsetRotateMatrix;
   uniform float u_time;
+  uniform float u_zoom;
+  uniform float u_resolution;
   
   attribute float a_test;
   uniform float u_test;
@@ -28,6 +30,8 @@ const INVALID_VERTEX_SHADER = `
   uniform mat4 u_offsetScaleMatrix;
   uniform mat4 u_offsetRotateMatrix;
   uniform float u_time;
+  uniform float u_zoom;
+  uniform float u_resolution;
   
   bla
   uniform float u_test;

test/spec/ol/webgl/shaderbuilder.test.js

@@ -18,6 +18,8 @@ uniform mat4 u_projectionMatrix;
 uniform mat4 u_offsetScaleMatrix;
 uniform mat4 u_offsetRotateMatrix;
 uniform float u_time;
+uniform float u_zoom;
+uniform float u_resolution;
 
 attribute vec2 a_position;
 attribute float a_index;
@@ -59,6 +61,8 @@ uniform mat4 u_projectionMatrix;
 uniform mat4 u_offsetScaleMatrix;
 uniform mat4 u_offsetRotateMatrix;
 uniform float u_time;
+uniform float u_zoom;
+uniform float u_resolution;
 uniform float u_myUniform;
 attribute vec2 a_position;
 attribute float a_index;
@@ -97,6 +101,8 @@ uniform mat4 u_projectionMatrix;
 uniform mat4 u_offsetScaleMatrix;
 uniform mat4 u_offsetRotateMatrix;
 uniform float u_time;
+uniform float u_zoom;
+uniform float u_resolution;
 
 attribute vec2 a_position;
 attribute float a_index;
@@ -130,6 +136,8 @@ uniform mat4 u_projectionMatrix;
 uniform mat4 u_offsetScaleMatrix;
 uniform mat4 u_offsetRotateMatrix;
 uniform float u_time;
+uniform float u_zoom;
+uniform float u_resolution;
 
 attribute vec2 a_position;
 attribute float a_index;
@@ -169,6 +177,8 @@ void main(void) {
 
       expect(builder.getSymbolFragmentShader()).to.eql(`precision mediump float;
 uniform float u_time;
+uniform float u_zoom;
+uniform float u_resolution;
 
 varying vec2 v_texCoord;
 varying vec2 v_quadCoord;
@@ -193,6 +203,8 @@ void main(void) {
 
       expect(builder.getSymbolFragmentShader()).to.eql(`precision mediump float;
 uniform float u_time;
+uniform float u_zoom;
+uniform float u_resolution;
 uniform float u_myUniform;
 uniform vec2 u_myUniform2;
 varying vec2 v_texCoord;
@@ -210,6 +222,8 @@ void main(void) {
 
       expect(builder.getSymbolFragmentShader(true)).to.eql(`precision mediump float;
 uniform float u_time;
+uniform float u_zoom;
+uniform float u_resolution;
 
 varying vec2 v_texCoord;
 varying vec2 v_quadCoord;