Added missing files.

3 files changed, 217 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 429d332..557f0dd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2005-10-05  Ian McIntosh  <ian_mcintosh@linuxadvocate.org>
 
+	* src/map_math.c:
+	* src/map_math.h: Added missing files.
+
+2005-10-05  Ian McIntosh  <ian_mcintosh@linuxadvocate.org>
+
 	* src/map_hittest.c:
 	* src/map_hittest.h: Added missing files.
 
diff --git a/src/map_math.c b/src/map_math.c
new file mode 100644
index 0000000..f9a7dbf
--- /dev/null
+++ b/src/map_math.c
@@ -0,0 +1,182 @@
+/***************************************************************************
+ *            map_math.c
+ *
+ *  Copyright  2005  Ian McIntosh
+ *  ian_mcintosh@linuxadvocate.org
+ ****************************************************************************/
+
+/*
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Library General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <gtk/gtk.h>
+#include "map.h"
+
+// ========================================================
+//  Coordinate Conversion Functions
+// ========================================================
+
+// convert pixels to a span of degrees
+gdouble map_pixels_to_degrees(map_t* pMap, gint16 nPixels, guint16 uZoomLevel)
+{
+	gdouble fMonitorPixelsPerInch = 85.333;	// XXX: don't hardcode this
+	gdouble fPixelsPerMeter = fMonitorPixelsPerInch * INCHES_PER_METER;
+	gdouble fMetersOfPixels = ((float)nPixels) / fPixelsPerMeter;
+
+	// If we had 3 meters of pixels (a very big monitor:) and the scale was 1000:1 then
+	// we would want to show 3000 meters worth of world space
+	gdouble fMetersOfWorld = ((float)g_sZoomLevels[uZoomLevel-1].uScale) * fMetersOfPixels;
+
+	//g_print("nPixels (%d) = fMetersOfPixels (%f) = fMetersOfWorld (%f) = fDegrees (%f)\n", nPixels, fMetersOfPixels, fMetersOfWorld, WORLD_METERS_TO_DEGREES(fMetersOfWorld));
+	return WORLD_METERS_TO_DEGREES(fMetersOfWorld);
+}
+
+gdouble map_degrees_to_pixels(map_t* pMap, gdouble fDegrees, guint16 uZoomLevel)
+{
+	gdouble fMonitorPixelsPerInch = 85.333;	// XXX: don't hardcode this
+
+	gdouble fResultInMeters = WORLD_DEGREES_TO_METERS(fDegrees);
+	gdouble fResultInPixels = (INCHES_PER_METER * fResultInMeters) * fMonitorPixelsPerInch;
+	fResultInPixels /= (float)g_sZoomLevels[uZoomLevel-1].uScale;
+	return fResultInPixels;
+}
+
+void map_windowpoint_to_mappoint(map_t* pMap, screenpoint_t* pScreenPoint, mappoint_t* pMapPoint)
+{
+	// Calculate the # of pixels away from the center point the click was
+	gint16 nPixelDeltaX = (gint)(pScreenPoint->nX) - (pMap->MapDimensions.uWidth / 2);
+	gint16 nPixelDeltaY = (gint)(pScreenPoint->nY) - (pMap->MapDimensions.uHeight / 2);
+
+	// Convert pixels to world coordinates
+	pMapPoint->fLongitude = pMap->MapCenter.fLongitude + map_pixels_to_degrees(pMap, nPixelDeltaX, pMap->uZoomLevel);
+	// reverse the X, clicking above
+	pMapPoint->fLatitude = pMap->MapCenter.fLatitude - map_pixels_to_degrees(pMap, nPixelDeltaY, pMap->uZoomLevel);
+}
+
+gboolean map_rects_overlap(const maprect_t* p1, const maprect_t* p2)
+{
+	if(p1->B.fLatitude < p2->A.fLatitude) return FALSE;
+	if(p1->B.fLongitude < p2->A.fLongitude) return FALSE;
+	if(p1->A.fLatitude > p2->B.fLatitude) return FALSE;
+	if(p1->A.fLongitude > p2->B.fLongitude) return FALSE;
+
+	return TRUE;
+}
+
+gboolean map_math_screenpoint_in_screenrect(screenpoint_t* pPt, screenrect_t* pRect)
+{
+	return(pPt->nX >= pRect->A.nX && pPt->nX <= pRect->B.nX && pPt->nY >= pRect->A.nY && pPt->nY <= pRect->B.nY);
+}
+
+gint map_screenrect_width(const screenrect_t* pRect)
+{
+	gint nDelta = pRect->B.nX - pRect->A.nX;	// NOTE: this works no matter which point has bigger values
+	return abs(nDelta);
+}
+gint map_screenrect_height(const screenrect_t* pRect)
+{
+	gint nDelta = pRect->B.nY - pRect->A.nY;	// NOTE: this works no matter which point has bigger values
+	return abs(nDelta);
+}
+
+void map_get_screenrect_centerpoint(const screenrect_t* pRect, screenpoint_t* pPoint)
+{
+	pPoint->nX = (pRect->A.nX + pRect->B.nX) / 2;		// NOTE: this works no matter which point has bigger values
+	pPoint->nY = (pRect->A.nY + pRect->B.nY) / 2;
+}
+
+gdouble map_get_distance_in_meters(mappoint_t* pA, mappoint_t* pB)
+{
+	// XXX: this function is broken.
+
+	// This functions calculates the length of the arc of the "greatcircle" that goes through
+	// the two points A and B and whos center is the center of the sphere, O.
+
+	// When we multiply this angle (in radians) by the radius, we get the length of the arc.
+
+	// NOTE: This algorithm wrongly assumes that Earth is a perfect sphere.
+	//       It is actually slightly egg shaped.  But it's good enough.
+
+	// All trig functions expect arguments in radians.
+	gdouble fLonA_Rad = DEG2RAD(pA->fLongitude);
+	gdouble fLonB_Rad = DEG2RAD(pB->fLongitude);
+	gdouble fLatA_Rad = DEG2RAD(pA->fLatitude);
+	gdouble fLatB_Rad = DEG2RAD(pB->fLatitude);
+
+	// Step 1. Calculate AOB (in radians).
+	// An explanation of this equation is at http://mathforum.org/library/drmath/view/51722.html
+	gdouble fAOB_Rad = acos((cos(fLatA_Rad) * cos(fLatB_Rad) * cos(fLonB_Rad - fLonA_Rad)) + (sin(fLatA_Rad) * sin(fLatB_Rad)));
+
+	// Step 2. Multiply the angle by the radius of the sphere to get arc length.
+	return fAOB_Rad * RADIUS_OF_WORLD_IN_METERS;
+}
+
+gdouble map_get_straight_line_distance_in_degrees(mappoint_t* p1, mappoint_t* p2)
+{
+	gdouble fDeltaX = ((p2->fLongitude) - (p1->fLongitude));
+	gdouble fDeltaY = ((p2->fLatitude) - (p1->fLatitude));
+
+	return sqrt((fDeltaX*fDeltaX) + (fDeltaY*fDeltaY));
+}
+
+gdouble map_get_distance_in_pixels(map_t* pMap, mappoint_t* p1, mappoint_t* p2)
+{
+	rendermetrics_t metrics;
+	map_get_render_metrics(pMap, &metrics);
+
+	gdouble fX1 = SCALE_X(&metrics, p1->fLongitude);
+	gdouble fY1 = SCALE_Y(&metrics, p1->fLatitude);
+
+	gdouble fX2 = SCALE_X(&metrics, p2->fLongitude);
+	gdouble fY2 = SCALE_Y(&metrics, p2->fLatitude);
+
+	gdouble fDeltaX = fX2 - fX1;
+	gdouble fDeltaY = fY2 - fY1;
+
+	return sqrt((fDeltaX*fDeltaX) + (fDeltaY*fDeltaY));
+}
+
+
+gboolean map_points_equal(mappoint_t* p1, mappoint_t* p2)
+{
+	return( p1->fLatitude == p2->fLatitude && p1->fLongitude == p2->fLongitude);
+}
+
+gboolean map_math_maprects_equal(maprect_t* pA, maprect_t* pB)
+{
+	return map_points_equal(&(pA->A), &(pB->A)) && map_points_equal(&(pA->B), &(pB->B));
+}
+
+
+#ifdef ROADSTER_DEAD_CODE
+/*
+gdouble map_distance_in_units_to_degrees(map_t* pMap, gdouble fDistance, gint nDistanceUnit)
+{
+	switch(nDistanceUnit) {
+		case UNIT_FEET:
+			return WORLD_FEET_TO_DEGREES(fDistance);
+		case UNIT_MILES:
+			return WORLD_MILES_TO_DEGREES(fDistance);
+		case UNIT_METERS:
+			return WORLD_METERS_TO_DEGREES(fDistance);
+		case UNIT_KILOMETERS:
+			return WORLD_KILOMETERS_TO_DEGREES(fDistance);
+		default:
+			g_warning("UNKNOWN DISTANCE UNIT (%d)\n", nDistanceUnit);
+			return 0;
+	}
+}
+*/
+#endif
diff --git a/src/map_math.h b/src/map_math.h
new file mode 100644
index 0000000..5643b98
--- /dev/null
+++ b/src/map_math.h
@@ -0,0 +1,30 @@
+/***************************************************************************
+ *            map_math.h
+ *
+ *  Copyright  2005  Ian McIntosh
+ *  ian_mcintosh@linuxadvocate.org
+ ****************************************************************************/
+
+/*
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Library General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef _MAP_MATH_H_
+#define _MAP_MATH_H_
+
+gboolean map_math_screenpoint_in_screenrect(screenpoint_t* pPt, screenrect_t* pRect);
+gboolean map_math_maprects_equal(maprect_t* pA, maprect_t* pB);
+
+#endif