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Diffstat (limited to 'jni/feature_mos/src/mosaic/Geometry.h')
| -rw-r--r-- | jni/feature_mos/src/mosaic/Geometry.h | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/jni/feature_mos/src/mosaic/Geometry.h b/jni/feature_mos/src/mosaic/Geometry.h new file mode 100644 index 000000000..0efa0f4a5 --- /dev/null +++ b/jni/feature_mos/src/mosaic/Geometry.h @@ -0,0 +1,156 @@ +/* + * Copyright (C) 2011 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +///////////////////////////// +// Geometry.h +// $Id: Geometry.h,v 1.2 2011/06/17 13:35:48 mbansal Exp $ + +#pragma once +#include "MosaicTypes.h" + +/////////////////////////////////////////////////////////////// +///////////////// BEG GLOBAL ROUTINES ///////////////////////// +/////////////////////////////////////////////////////////////// + + +inline double hypotSq(double a, double b) +{ + return ((a)*(a)+(b)*(b)); +} + +inline void ClipRect(double x, double y, BlendRect &brect) +{ + if (y < brect.bot) brect.bot = y; + if (y > brect.top) brect.top = y; + if (x < brect.lft) brect.lft = x; + if (x > brect.rgt) brect.rgt = x; +} + +inline void ClipRect(BlendRect rrect, BlendRect &brect) +{ + if (rrect.bot < brect.bot) brect.bot = rrect.bot; + if (rrect.top > brect.top) brect.top = rrect.top; + if (rrect.lft < brect.lft) brect.lft = rrect.lft; + if (rrect.rgt > brect.rgt) brect.rgt = rrect.rgt; +} + +// Clip x to be within [-border,width+border-1] +inline void clipToSegment(int &x, int width, int border) +{ + if(x < -border) + x = -border; + else if(x >= width+border) + x = width + border - 1; +} + +// Return true if x within [-border,width+border-1] +inline bool inSegment(int x, int width, int border) +{ + return (x >= -border && x < width + border - 1); +} + +inline void FindTriangleCentroid(double x0, double y0, double x1, double y1, + double x2, double y2, + double &mass, double ¢X, double ¢Y) +{ + // Calculate the centroid of the triangle + centX = (x0 + x1 + x2) / 3.0; + centY = (y0 + y1 + y2) / 3.0; + + // Calculate 2*Area for the triangle + if (y0 == y2) + { + if (x0 == x1) + { + mass = fabs((y1 - y0) * (x2 - x0)); // Special case 1a + } + else + { + mass = fabs((y1 - y0) * (x1 - x0)); // Special case 1b + } + } + else if (x0 == x2) + { + if (x0 == x1) + { + mass = fabs((x2 - x0) * (y2 - y0)); // Special case 2a + } + else + { + mass = fabs((x1 - x0) * (y2 - y0)); // Special case 2a + } + } + else if (x1 == x2) + { + mass = fabs((x1 - x0) * (y2 - y0)); // Special case 3 + } + else + { + // Calculate line equation from x0,y0 to x2,y2 + double dx = x2 - x0; + double dy = y2 - y0; + // Calculate the length of the side + double len1 = sqrt(dx * dx + dy * dy); + double m1 = dy / dx; + double b1 = y0 - m1 * x0; + // Calculate the line that goes through x1,y1 and is perpendicular to + // the other line + double m2 = 1.0 / m1; + double b2 = y1 - m2 * x1; + // Calculate the intersection of the two lines + if (fabs( m1 - m2 ) > 1.e-6) + { + double x = (b2 - b1) / (m1 - m2); + // the mass is the base * height + dx = x1 - x; + dy = y1 - m1 * x + b1; + mass = len1 * sqrt(dx * dx + dy * dy); + } + else + { + mass = fabs( (y1 - y0) * (x2 - x0) ); + } + } +} + +inline void FindQuadCentroid(double x0, double y0, double x1, double y1, double x2, double y2, double x3, double y3, + double ¢X, double ¢Y) + +{ + // To find the centroid: + // 1) Divide the quadrilateral into two triangles by scribing a diagonal + // 2) Calculate the centroid of each triangle (the intersection of the angle bisections). + // 3) Find the centroid of the quad by weighting each triangle centroids by their area. + + // Calculate the corner points + double z; + + // The quad is split from x0,y0 to x2,y2 + double mass1, mass2, cent1x, cent2x, cent1y, cent2y; + FindTriangleCentroid(x0, y0, x1, y1, x2, y2, mass1, cent1x, cent1y); + FindTriangleCentroid(x0, y0, x3, y3, x2, y2, mass2, cent2x, cent2y); + + // determine position of quad centroid + z = mass2 / (mass1 + mass2); + centX = cent1x + (cent2x - cent1x) * z; + centY = cent1y + (cent2y - cent1y) * z; +} + +/////////////////////////////////////////////////////////////// +////////////////// END GLOBAL ROUTINES //////////////////////// +/////////////////////////////////////////////////////////////// + + |