planning

node_modules/ol/webgl/ShaderBuilder.js

@@ -0,0 +1,450 @@
+/**
+ * Classes and utilities for generating shaders from literal style objects
+ * @module ol/webgl/ShaderBuilder
+ */
+import { ValueTypes, expressionToGlsl, getStringNumberEquivalent, uniformNameForVariable, } from '../style/expressions.js';
+/**
+ * @typedef {Object} VaryingDescription
+ * @property {string} name Varying name, as will be declared in the header.
+ * @property {string} type Varying type, either `float`, `vec2`, `vec4`...
+ * @property {string} expression Expression which will be assigned to the varying in the vertex shader, and
+ * passed on to the fragment shader.
+ */
+/**
+ * @classdesc
+ * This class implements a classic builder pattern for generating many different types of shaders.
+ * Methods can be chained, e. g.:
+ *
+ * ```js
+ * const shader = new ShaderBuilder()
+ *   .addVarying('v_width', 'float', 'a_width')
+ *   .addUniform('u_time')
+ *   .setColorExpression('...')
+ *   .setSizeExpression('...')
+ *   .outputSymbolFragmentShader();
+ * ```
+ */
+var ShaderBuilder = /** @class */ (function () {
+    function ShaderBuilder() {
+        /**
+         * Uniforms; these will be declared in the header (should include the type).
+         * @type {Array<string>}
+         * @private
+         */
+        this.uniforms = [];
+        /**
+         * Attributes; these will be declared in the header (should include the type).
+         * @type {Array<string>}
+         * @private
+         */
+        this.attributes = [];
+        /**
+         * Varyings with a name, a type and an expression.
+         * @type {Array<VaryingDescription>}
+         * @private
+         */
+        this.varyings = [];
+        /**
+         * @type {string}
+         * @private
+         */
+        this.sizeExpression = 'vec2(1.0)';
+        /**
+         * @type {string}
+         * @private
+         */
+        this.rotationExpression = '0.0';
+        /**
+         * @type {string}
+         * @private
+         */
+        this.offsetExpression = 'vec2(0.0)';
+        /**
+         * @type {string}
+         * @private
+         */
+        this.colorExpression = 'vec4(1.0)';
+        /**
+         * @type {string}
+         * @private
+         */
+        this.texCoordExpression = 'vec4(0.0, 0.0, 1.0, 1.0)';
+        /**
+         * @type {string}
+         * @private
+         */
+        this.discardExpression = 'false';
+        /**
+         * @type {boolean}
+         * @private
+         */
+        this.rotateWithView = false;
+    }
+    /**
+     * Adds a uniform accessible in both fragment and vertex shaders.
+     * The given name should include a type, such as `sampler2D u_texture`.
+     * @param {string} name Uniform name
+     * @return {ShaderBuilder} the builder object
+     */
+    ShaderBuilder.prototype.addUniform = function (name) {
+        this.uniforms.push(name);
+        return this;
+    };
+    /**
+     * Adds an attribute accessible in the vertex shader, read from the geometry buffer.
+     * The given name should include a type, such as `vec2 a_position`.
+     * @param {string} name Attribute name
+     * @return {ShaderBuilder} the builder object
+     */
+    ShaderBuilder.prototype.addAttribute = function (name) {
+        this.attributes.push(name);
+        return this;
+    };
+    /**
+     * Adds a varying defined in the vertex shader and accessible from the fragment shader.
+     * The type and expression of the varying have to be specified separately.
+     * @param {string} name Varying name
+     * @param {'float'|'vec2'|'vec3'|'vec4'} type Type
+     * @param {string} expression Expression used to assign a value to the varying.
+     * @return {ShaderBuilder} the builder object
+     */
+    ShaderBuilder.prototype.addVarying = function (name, type, expression) {
+        this.varyings.push({
+            name: name,
+            type: type,
+            expression: expression,
+        });
+        return this;
+    };
+    /**
+     * Sets an expression to compute the size of the shape.
+     * This expression can use all the uniforms and attributes available
+     * in the vertex shader, and should evaluate to a `vec2` value.
+     * @param {string} expression Size expression
+     * @return {ShaderBuilder} the builder object
+     */
+    ShaderBuilder.prototype.setSizeExpression = function (expression) {
+        this.sizeExpression = expression;
+        return this;
+    };
+    /**
+     * Sets an expression to compute the rotation of the shape.
+     * This expression can use all the uniforms and attributes available
+     * in the vertex shader, and should evaluate to a `float` value in radians.
+     * @param {string} expression Size expression
+     * @return {ShaderBuilder} the builder object
+     */
+    ShaderBuilder.prototype.setRotationExpression = function (expression) {
+        this.rotationExpression = expression;
+        return this;
+    };
+    /**
+     * Sets an expression to compute the offset of the symbol from the point center.
+     * This expression can use all the uniforms and attributes available
+     * in the vertex shader, and should evaluate to a `vec2` value.
+     * Note: will only be used for point geometry shaders.
+     * @param {string} expression Offset expression
+     * @return {ShaderBuilder} the builder object
+     */
+    ShaderBuilder.prototype.setSymbolOffsetExpression = function (expression) {
+        this.offsetExpression = expression;
+        return this;
+    };
+    /**
+     * Sets an expression to compute the color of the shape.
+     * This expression can use all the uniforms, varyings and attributes available
+     * in the fragment shader, and should evaluate to a `vec4` value.
+     * @param {string} expression Color expression
+     * @return {ShaderBuilder} the builder object
+     */
+    ShaderBuilder.prototype.setColorExpression = function (expression) {
+        this.colorExpression = expression;
+        return this;
+    };
+    /**
+     * Sets an expression to compute the texture coordinates of the vertices.
+     * This expression can use all the uniforms and attributes available
+     * in the vertex shader, and should evaluate to a `vec4` value.
+     * @param {string} expression Texture coordinate expression
+     * @return {ShaderBuilder} the builder object
+     */
+    ShaderBuilder.prototype.setTextureCoordinateExpression = function (expression) {
+        this.texCoordExpression = expression;
+        return this;
+    };
+    /**
+     * Sets an expression to determine whether a fragment (pixel) should be discarded,
+     * i.e. not drawn at all.
+     * This expression can use all the uniforms, varyings and attributes available
+     * in the fragment shader, and should evaluate to a `bool` value (it will be
+     * used in an `if` statement)
+     * @param {string} expression Fragment discard expression
+     * @return {ShaderBuilder} the builder object
+     */
+    ShaderBuilder.prototype.setFragmentDiscardExpression = function (expression) {
+        this.discardExpression = expression;
+        return this;
+    };
+    /**
+     * Sets whether the symbols should rotate with the view or stay aligned with the map.
+     * Note: will only be used for point geometry shaders.
+     * @param {boolean} rotateWithView Rotate with view
+     * @return {ShaderBuilder} the builder object
+     */
+    ShaderBuilder.prototype.setSymbolRotateWithView = function (rotateWithView) {
+        this.rotateWithView = rotateWithView;
+        return this;
+    };
+    /**
+     * @return {string} Previously set size expression
+     */
+    ShaderBuilder.prototype.getSizeExpression = function () {
+        return this.sizeExpression;
+    };
+    /**
+     * @return {string} Previously set symbol offset expression
+     */
+    ShaderBuilder.prototype.getOffsetExpression = function () {
+        return this.offsetExpression;
+    };
+    /**
+     * @return {string} Previously set color expression
+     */
+    ShaderBuilder.prototype.getColorExpression = function () {
+        return this.colorExpression;
+    };
+    /**
+     * @return {string} Previously set texture coordinate expression
+     */
+    ShaderBuilder.prototype.getTextureCoordinateExpression = function () {
+        return this.texCoordExpression;
+    };
+    /**
+     * @return {string} Previously set fragment discard expression
+     */
+    ShaderBuilder.prototype.getFragmentDiscardExpression = function () {
+        return this.discardExpression;
+    };
+    /**
+     * Generates a symbol vertex shader from the builder parameters,
+     * intended to be used on point geometries.
+     *
+     * Three uniforms are hardcoded in all shaders: `u_projectionMatrix`, `u_offsetScaleMatrix`,
+     * `u_offsetRotateMatrix`, `u_time`.
+     *
+     * The following attributes are hardcoded and expected to be present in the vertex buffers:
+     * `vec2 a_position`, `float a_index` (being the index of the vertex in the quad, 0 to 3).
+     *
+     * The following varyings are hardcoded and gives the coordinate of the pixel both in the quad and on the texture:
+     * `vec2 v_quadCoord`, `vec2 v_texCoord`
+     *
+     * @param {boolean} [forHitDetection] If true, the shader will be modified to include hit detection variables
+     * (namely, hit color with encoded feature id).
+     * @return {string} The full shader as a string.
+     */
+    ShaderBuilder.prototype.getSymbolVertexShader = function (forHitDetection) {
+        var offsetMatrix = this.rotateWithView
+            ? 'u_offsetScaleMatrix * u_offsetRotateMatrix'
+            : 'u_offsetScaleMatrix';
+        var attributes = this.attributes;
+        var varyings = this.varyings;
+        if (forHitDetection) {
+            attributes = attributes.concat('vec4 a_hitColor');
+            varyings = varyings.concat({
+                name: 'v_hitColor',
+                type: 'vec4',
+                expression: 'a_hitColor',
+            });
+        }
+        return "precision mediump float;\nuniform mat4 u_projectionMatrix;\nuniform mat4 u_offsetScaleMatrix;\nuniform mat4 u_offsetRotateMatrix;\nuniform float u_time;\nuniform float u_zoom;\nuniform float u_resolution;\n".concat(this.uniforms
+            .map(function (uniform) {
+            return 'uniform ' + uniform + ';';
+        })
+            .join('\n'), "\nattribute vec2 a_position;\nattribute float a_index;\n").concat(attributes
+            .map(function (attribute) {
+            return 'attribute ' + attribute + ';';
+        })
+            .join('\n'), "\nvarying vec2 v_texCoord;\nvarying vec2 v_quadCoord;\n").concat(varyings
+            .map(function (varying) {
+            return 'varying ' + varying.type + ' ' + varying.name + ';';
+        })
+            .join('\n'), "\nvoid main(void) {\n  mat4 offsetMatrix = ").concat(offsetMatrix, ";\n  vec2 halfSize = ").concat(this.sizeExpression, " * 0.5;\n  vec2 offset = ").concat(this.offsetExpression, ";\n  float angle = ").concat(this.rotationExpression, ";\n  float offsetX;\n  float offsetY;\n  if (a_index == 0.0) {\n    offsetX = (offset.x - halfSize.x) * cos(angle) + (offset.y - halfSize.y) * sin(angle);\n    offsetY = (offset.y - halfSize.y) * cos(angle) - (offset.x - halfSize.x) * sin(angle);\n  } else if (a_index == 1.0) {\n    offsetX = (offset.x + halfSize.x) * cos(angle) + (offset.y - halfSize.y) * sin(angle);\n    offsetY = (offset.y - halfSize.y) * cos(angle) - (offset.x + halfSize.x) * sin(angle);\n  } else if (a_index == 2.0) {\n    offsetX = (offset.x + halfSize.x) * cos(angle) + (offset.y + halfSize.y) * sin(angle);\n    offsetY = (offset.y + halfSize.y) * cos(angle) - (offset.x + halfSize.x) * sin(angle);\n  } else {\n    offsetX = (offset.x - halfSize.x) * cos(angle) + (offset.y + halfSize.y) * sin(angle);\n    offsetY = (offset.y + halfSize.y) * cos(angle) - (offset.x - halfSize.x) * sin(angle);\n  }\n  vec4 offsets = offsetMatrix * vec4(offsetX, offsetY, 0.0, 0.0);\n  gl_Position = u_projectionMatrix * vec4(a_position, 0.0, 1.0) + offsets;\n  vec4 texCoord = ").concat(this.texCoordExpression, ";\n  float u = a_index == 0.0 || a_index == 3.0 ? texCoord.s : texCoord.p;\n  float v = a_index == 2.0 || a_index == 3.0 ? texCoord.t : texCoord.q;\n  v_texCoord = vec2(u, v);\n  u = a_index == 0.0 || a_index == 3.0 ? 0.0 : 1.0;\n  v = a_index == 2.0 || a_index == 3.0 ? 0.0 : 1.0;\n  v_quadCoord = vec2(u, v);\n").concat(varyings
+            .map(function (varying) {
+            return '  ' + varying.name + ' = ' + varying.expression + ';';
+        })
+            .join('\n'), "\n}");
+    };
+    /**
+     * Generates a symbol fragment shader from the builder parameters,
+     * intended to be used on point geometries.
+     *
+     * Expects the following varyings to be transmitted by the vertex shader:
+     * `vec2 v_quadCoord`, `vec2 v_texCoord`
+     *
+     * @param {boolean} [forHitDetection] If true, the shader will be modified to include hit detection variables
+     * (namely, hit color with encoded feature id).
+     * @return {string} The full shader as a string.
+     */
+    ShaderBuilder.prototype.getSymbolFragmentShader = function (forHitDetection) {
+        var hitDetectionBypass = forHitDetection
+            ? '  if (gl_FragColor.a < 0.1) { discard; } gl_FragColor = v_hitColor;'
+            : '';
+        var varyings = this.varyings;
+        if (forHitDetection) {
+            varyings = varyings.concat({
+                name: 'v_hitColor',
+                type: 'vec4',
+                expression: 'a_hitColor',
+            });
+        }
+        return "precision mediump float;\nuniform float u_time;\nuniform float u_zoom;\nuniform float u_resolution;\n".concat(this.uniforms
+            .map(function (uniform) {
+            return 'uniform ' + uniform + ';';
+        })
+            .join('\n'), "\nvarying vec2 v_texCoord;\nvarying vec2 v_quadCoord;\n").concat(varyings
+            .map(function (varying) {
+            return 'varying ' + varying.type + ' ' + varying.name + ';';
+        })
+            .join('\n'), "\nvoid main(void) {\n  if (").concat(this.discardExpression, ") { discard; }\n  gl_FragColor = ").concat(this.colorExpression, ";\n  gl_FragColor.rgb *= gl_FragColor.a;\n").concat(hitDetectionBypass, "\n}");
+    };
+    return ShaderBuilder;
+}());
+export { ShaderBuilder };
+/**
+ * @typedef {Object} StyleParseResult
+ * @property {ShaderBuilder} builder Shader builder pre-configured according to a given style
+ * @property {Object<string,import("./Helper").UniformValue>} uniforms Uniform definitions.
+ * @property {Array<import("../renderer/webgl/PointsLayer").CustomAttribute>} attributes Attribute descriptions.
+ */
+/**
+ * Parses a {@link import("../style/literal").LiteralStyle} object and returns a {@link ShaderBuilder}
+ * object that has been configured according to the given style, as well as `attributes` and `uniforms`
+ * arrays to be fed to the `WebGLPointsRenderer` class.
+ *
+ * Also returns `uniforms` and `attributes` properties as expected by the
+ * {@link module:ol/renderer/webgl/PointsLayer~WebGLPointsLayerRenderer}.
+ *
+ * @param {import("../style/literal").LiteralStyle} style Literal style.
+ * @return {StyleParseResult} Result containing shader params, attributes and uniforms.
+ */
+export function parseLiteralStyle(style) {
+    var symbStyle = style.symbol;
+    var size = symbStyle.size !== undefined ? symbStyle.size : 1;
+    var color = symbStyle.color || 'white';
+    var texCoord = symbStyle.textureCoord || [0, 0, 1, 1];
+    var offset = symbStyle.offset || [0, 0];
+    var opacity = symbStyle.opacity !== undefined ? symbStyle.opacity : 1;
+    var rotation = symbStyle.rotation !== undefined ? symbStyle.rotation : 0;
+    /**
+     * @type {import("../style/expressions.js").ParsingContext}
+     */
+    var vertContext = {
+        inFragmentShader: false,
+        variables: [],
+        attributes: [],
+        stringLiteralsMap: {},
+        functions: {},
+    };
+    var parsedSize = expressionToGlsl(vertContext, size, ValueTypes.NUMBER_ARRAY | ValueTypes.NUMBER);
+    var parsedOffset = expressionToGlsl(vertContext, offset, ValueTypes.NUMBER_ARRAY);
+    var parsedTexCoord = expressionToGlsl(vertContext, texCoord, ValueTypes.NUMBER_ARRAY);
+    var parsedRotation = expressionToGlsl(vertContext, rotation, ValueTypes.NUMBER);
+    /**
+     * @type {import("../style/expressions.js").ParsingContext}
+     */
+    var fragContext = {
+        inFragmentShader: true,
+        variables: vertContext.variables,
+        attributes: [],
+        stringLiteralsMap: vertContext.stringLiteralsMap,
+        functions: {},
+    };
+    var parsedColor = expressionToGlsl(fragContext, color, ValueTypes.COLOR);
+    var parsedOpacity = expressionToGlsl(fragContext, opacity, ValueTypes.NUMBER);
+    var opacityFilter = '1.0';
+    var visibleSize = "vec2(".concat(expressionToGlsl(fragContext, size, ValueTypes.NUMBER_ARRAY | ValueTypes.NUMBER), ").x");
+    switch (symbStyle.symbolType) {
+        case 'square':
+            break;
+        case 'image':
+            break;
+        // taken from https://thebookofshaders.com/07/
+        case 'circle':
+            opacityFilter = "(1.0-smoothstep(1.-4./".concat(visibleSize, ",1.,dot(v_quadCoord-.5,v_quadCoord-.5)*4.))");
+            break;
+        case 'triangle':
+            var st = '(v_quadCoord*2.-1.)';
+            var a = "(atan(".concat(st, ".x,").concat(st, ".y))");
+            opacityFilter = "(1.0-smoothstep(.5-3./".concat(visibleSize, ",.5,cos(floor(.5+").concat(a, "/2.094395102)*2.094395102-").concat(a, ")*length(").concat(st, ")))");
+            break;
+        default:
+            throw new Error('Unexpected symbol type: ' + symbStyle.symbolType);
+    }
+    var builder = new ShaderBuilder()
+        .setSizeExpression("vec2(".concat(parsedSize, ")"))
+        .setRotationExpression(parsedRotation)
+        .setSymbolOffsetExpression(parsedOffset)
+        .setTextureCoordinateExpression(parsedTexCoord)
+        .setSymbolRotateWithView(!!symbStyle.rotateWithView)
+        .setColorExpression("vec4(".concat(parsedColor, ".rgb, ").concat(parsedColor, ".a * ").concat(parsedOpacity, " * ").concat(opacityFilter, ")"));
+    if (style.filter) {
+        var parsedFilter = expressionToGlsl(fragContext, style.filter, ValueTypes.BOOLEAN);
+        builder.setFragmentDiscardExpression("!".concat(parsedFilter));
+    }
+    /** @type {Object<string,import("../webgl/Helper").UniformValue>} */
+    var uniforms = {};
+    // define one uniform per variable
+    fragContext.variables.forEach(function (varName) {
+        var uniformName = uniformNameForVariable(varName);
+        builder.addUniform("float ".concat(uniformName));
+        uniforms[uniformName] = function () {
+            if (!style.variables || style.variables[varName] === undefined) {
+                throw new Error("The following variable is missing from the style: ".concat(varName));
+            }
+            var value = style.variables[varName];
+            if (typeof value === 'string') {
+                value = getStringNumberEquivalent(vertContext, value);
+            }
+            return value !== undefined ? value : -9999999; // to avoid matching with the first string literal
+        };
+    });
+    if (symbStyle.symbolType === 'image' && symbStyle.src) {
+        var texture = new Image();
+        texture.crossOrigin =
+            symbStyle.crossOrigin === undefined ? 'anonymous' : symbStyle.crossOrigin;
+        texture.src = symbStyle.src;
+        builder
+            .addUniform('sampler2D u_texture')
+            .setColorExpression(builder.getColorExpression() + ' * texture2D(u_texture, v_texCoord)');
+        uniforms['u_texture'] = texture;
+    }
+    // for each feature attribute used in the fragment shader, define a varying that will be used to pass data
+    // from the vertex to the fragment shader, as well as an attribute in the vertex shader (if not already present)
+    fragContext.attributes.forEach(function (attrName) {
+        if (vertContext.attributes.indexOf(attrName) === -1) {
+            vertContext.attributes.push(attrName);
+        }
+        builder.addVarying("v_".concat(attrName), 'float', "a_".concat(attrName));
+    });
+    // for each feature attribute used in the vertex shader, define an attribute in the vertex shader.
+    vertContext.attributes.forEach(function (attrName) {
+        builder.addAttribute("float a_".concat(attrName));
+    });
+    return {
+        builder: builder,
+        attributes: vertContext.attributes.map(function (attributeName) {
+            return {
+                name: attributeName,
+                callback: function (feature, props) {
+                    var value = props[attributeName];
+                    if (typeof value === 'string') {
+                        value = getStringNumberEquivalent(vertContext, value);
+                    }
+                    return value !== undefined ? value : -9999999; // to avoid matching with the first string literal
+                },
+            };
+        }),
+        uniforms: uniforms,
+    };
+}
+//# sourceMappingURL=ShaderBuilder.js.map