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Stronger typing of triangles and triangulation

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This commit is contained in:
Petr Sloup
2015-06-03 15:52:02 +02:00
parent e14bede9e9
commit bf65b8a4fe
2 changed files with 62 additions and 66 deletions
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29
src/ol/reproj/reproj.js
View File

@@ -68,7 +68,9 @@ ol.reproj.renderTriangles = function(context,
image.width + 1, image.height + 1); image.width + 1, image.height + 1);
}; };
goog.array.forEach(triangulation, function(tri, i, arr) { var shiftDistance = triangulation.shiftDistance;
goog.array.forEach(triangulation.triangles, function(tri, i, arr) {
context.save(); context.save();
var targetTL = ol.extent.getTopLeft(targetExtent); var targetTL = ol.extent.getTopLeft(targetExtent);
@@ -93,16 +95,17 @@ ol.reproj.renderTriangles = function(context,
* | 0 0 0 x1 y1 1 | |a11| |v1| * | 0 0 0 x1 y1 1 | |a11| |v1|
* | 0 0 0 x2 y2 1 | |a12| |v2| * | 0 0 0 x2 y2 1 | |a12| |v2|
*/ */
var x0 = tri[0][0][0], y0 = tri[0][0][1], var src = tri.source, tgt = tri.target;
x1 = tri[1][0][0], y1 = tri[1][0][1], var x0 = src[0][0], y0 = src[0][1],
x2 = tri[2][0][0], y2 = tri[2][0][1]; x1 = src[1][0], y1 = src[1][1],
var u0 = tri[0][1][0] - targetTL[0], v0 = -(tri[0][1][1] - targetTL[1]), x2 = src[2][0], y2 = src[2][1];
u1 = tri[1][1][0] - targetTL[0], v1 = -(tri[1][1][1] - targetTL[1]), var u0 = tgt[0][0] - targetTL[0], v0 = -(tgt[0][1] - targetTL[1]),
u2 = tri[2][1][0] - targetTL[0], v2 = -(tri[2][1][1] - targetTL[1]); u1 = tgt[1][0] - targetTL[0], v1 = -(tgt[1][1] - targetTL[1]),
if (tri.shiftDistance) { u2 = tgt[2][0] - targetTL[0], v2 = -(tgt[2][1] - targetTL[1]);
x0 = goog.math.modulo(x0 + tri.shiftDistance, tri.shiftDistance); if (tri.needsShift) {
x1 = goog.math.modulo(x1 + tri.shiftDistance, tri.shiftDistance); x0 = goog.math.modulo(x0 + shiftDistance, shiftDistance);
x2 = goog.math.modulo(x2 + tri.shiftDistance, tri.shiftDistance); x1 = goog.math.modulo(x1 + shiftDistance, shiftDistance);
x2 = goog.math.modulo(x2 + shiftDistance, shiftDistance);
} }
var augmentedMatrix = [ var augmentedMatrix = [
[x0, y0, 1, 0, 0, 0, u0 / targetResolution], [x0, y0, 1, 0, 0, 0, u0 / targetResolution],
@@ -149,9 +152,9 @@ ol.reproj.renderTriangles = function(context,
context.save(); context.save();
var tlSrcFromData = ol.extent.getTopLeft(src.extent); var tlSrcFromData = ol.extent.getTopLeft(src.extent);
context.translate(tlSrcFromData[0], tlSrcFromData[1]); context.translate(tlSrcFromData[0], tlSrcFromData[1]);
if (tri.shiftDistance) { if (tri.needsShift) {
context.save(); context.save();
context.translate(tri.shiftDistance, 0); context.translate(shiftDistance, 0);
renderImage(src.image); renderImage(src.image);
context.restore(); context.restore();
renderImage(src.image); renderImage(src.image);

99
src/ol/reproj/triangulation.js
View File

@@ -3,16 +3,27 @@ goog.provide('ol.reproj.triangulation');
goog.require('goog.array'); goog.require('goog.array');
goog.require('goog.math'); goog.require('goog.math');
goog.require('ol.coordinate');
goog.require('ol.extent'); goog.require('ol.extent');
goog.require('ol.proj'); goog.require('ol.proj');
/** /**
* Array of triangles, * Single triangle; consists of 3 source points and 3 target points.
* each triangles is Array (length=3) of * `needsShift` can be used to indicate that the whole triangle has to be
* projected point pairs (length=2; [src, dst]), * shifted during reprojection. This is needed for triangles crossing edges
* each point is ol.Coordinate. * of the source projection (dateline).
* @typedef {Array.<Array.<Array.<ol.Coordinate>>>} *
* @typedef {{source: Array.<ol.Coordinate>,
* target: Array.<ol.Coordinate>,
* needsShift: boolean}}
*/
ol.reproj.Triangle;
/**
* @typedef {{triangles: Array.<ol.reproj.Triangle>,
* shiftDistance: number}}
*/ */
ol.reproj.Triangulation; ol.reproj.Triangulation;
@@ -69,50 +80,30 @@ ol.reproj.triangulation.addTriangleIfValid_ = function(triangulation, a, b, c,
c = transformFwd(cSrc); c = transformFwd(cSrc);
} }
} }
var shiftDistance = 0; var needsShift = false;
if (sourceProj.isGlobal()) { if (sourceProj.canWrapX()) {
// determine if the triangle crosses the dateline here // determine if the triangle crosses the dateline here
// This can be detected by transforming centroid of the target triangle. // This can be detected by transforming centroid of the target triangle.
// If the transformed centroid is outside the transformed triangle, // If the transformed centroid is outside the transformed triangle,
// the triangle wraps around projection extent. // the triangle wraps around projection extent.
// In such case, the
var srcExtent = ol.extent.createEmpty();
ol.extent.extendCoordinate(srcExtent, aSrc);
ol.extent.extendCoordinate(srcExtent, bSrc);
ol.extent.extendCoordinate(srcExtent, cSrc);
var centroid = [(a[0] + b[0] + c[0]) / 3, var centroid = [(a[0] + b[0] + c[0]) / 3,
(a[1] + b[1] + c[1]) / 3]; (a[1] + b[1] + c[1]) / 3];
var centroidSrc = transformInv(centroid); var centroidSrc = transformInv(centroid);
var pInTriangle = function(p, p0, p1, p2) { if (!ol.coordinate.isInTriangle(centroidSrc, aSrc, bSrc, cSrc)) {
//TODO: move somewhere else needsShift = true;
var A = (-p1[1] * p2[0] + p0[1] * (-p1[0] + p2[0]) +
p0[0] * (p1[1] - p2[1]) + p1[0] * p2[1]) / 2;
var sign = A < 0 ? -1 : 1;
var s = (p0[1] * p2[0] - p0[0] * p2[1] +
(p2[1] - p0[1]) * p[0] +
(p0[0] - p2[0]) * p[1]) * sign;
var t = (p0[0] * p1[1] - p0[1] * p1[0] +
(p0[1] - p1[1]) * p[0] +
(p1[0] - p0[0]) * p[1]) * sign;
return s > 0 && t > 0 && (s + t) < 2 * A * sign;
};
if (!pInTriangle(centroidSrc, aSrc, bSrc, cSrc)) {
var sourceProjExtent = sourceProj.getExtent();
shiftDistance = ol.extent.getWidth(sourceProjExtent);
} }
} }
var tri = [[aSrc, a], [bSrc, b], [cSrc, c]]; triangulation.triangles.push({
// TODO: typing ! do not add properties to arrays ! source: [aSrc, bSrc, cSrc],
tri.shiftDistance = shiftDistance; target: [a, b, c],
if (shiftDistance) { needsShift: needsShift
triangulation.shiftDistance = shiftDistance; });
if (needsShift) {
var sourceProjExtent = sourceProj.getExtent();
triangulation.shiftDistance = ol.extent.getWidth(sourceProjExtent);
} }
triangulation.push(tri);
}; };
@@ -130,7 +121,10 @@ ol.reproj.triangulation.addTriangleIfValid_ = function(triangulation, a, b, c,
ol.reproj.triangulation.createForExtent = function(extent, sourceProj, ol.reproj.triangulation.createForExtent = function(extent, sourceProj,
targetProj, opt_maxTargetExtent, opt_maxSourceExtent, opt_subdiv) { targetProj, opt_maxTargetExtent, opt_maxSourceExtent, opt_subdiv) {
var triangulation = []; var triangulation = {
triangles: [],
shiftDistance: 0
};
var tlDst = ol.extent.getTopLeft(extent); var tlDst = ol.extent.getTopLeft(extent);
var brDst = ol.extent.getBottomRight(extent); var brDst = ol.extent.getBottomRight(extent);
@@ -178,26 +172,25 @@ ol.reproj.triangulation.createForExtent = function(extent, sourceProj,
ol.reproj.triangulation.getSourceExtent = function(triangulation) { ol.reproj.triangulation.getSourceExtent = function(triangulation) {
var extent = ol.extent.createEmpty(); var extent = ol.extent.createEmpty();
if (triangulation.shiftDistance) { var distance = triangulation.shiftDistance;
var shiftDistance = triangulation.shiftDistance; if (distance > 0) {
goog.array.forEach(triangulation, function(triangle, i, arr) { goog.array.forEach(triangulation.triangles, function(triangle, i, arr) {
var src = triangle.source;
ol.extent.extendCoordinate(extent, ol.extent.extendCoordinate(extent,
[goog.math.modulo(triangle[0][0][0] + shiftDistance, shiftDistance), [goog.math.modulo(src[0][0] + distance, distance), src[0][1]]);
triangle[0][0][1]]);
ol.extent.extendCoordinate(extent, ol.extent.extendCoordinate(extent,
[goog.math.modulo(triangle[1][0][0] + shiftDistance, shiftDistance), [goog.math.modulo(src[1][0] + distance, distance), src[1][1]]);
triangle[1][0][1]]);
ol.extent.extendCoordinate(extent, ol.extent.extendCoordinate(extent,
[goog.math.modulo(triangle[2][0][0] + shiftDistance, shiftDistance), [goog.math.modulo(src[2][0] + distance, distance), src[2][1]]);
triangle[2][0][1]]);
}); });
if (extent[0] > shiftDistance / 2) extent[0] -= shiftDistance; if (extent[0] > distance / 2) extent[0] -= distance;
if (extent[2] > shiftDistance / 2) extent[2] -= shiftDistance; if (extent[2] > distance / 2) extent[2] -= distance;
} else { } else {
goog.array.forEach(triangulation, function(triangle, i, arr) { goog.array.forEach(triangulation.triangles, function(triangle, i, arr) {
ol.extent.extendCoordinate(extent, triangle[0][0]); var src = triangle.source;
ol.extent.extendCoordinate(extent, triangle[1][0]); ol.extent.extendCoordinate(extent, src[0]);
ol.extent.extendCoordinate(extent, triangle[2][0]); ol.extent.extendCoordinate(extent, src[1]);
ol.extent.extendCoordinate(extent, src[2]);
}); });
} }