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#include "emb-line.h"
#include "emb-logging.h"
#include "emb-vector.h"
#include <stdlib.h>
/**************************************************/
/* EmbLine */
/**************************************************/
double embLine_x1(EmbLine line)
{
return line.x1;
}
double embLine_y1(EmbLine line)
{
return line.y1;
}
double embLine_x2(EmbLine line)
{
return line.x2;
}
double embLine_y2(EmbLine line)
{
return line.y2;
}
/**************************************************/
/* EmbLineObject */
/**************************************************/
/* Returns an EmbLineObject. It is created on the stack. */
EmbLineObject embLineObject_make(double x1, double y1, double x2, double y2)
{
EmbLineObject stackLineObj;
stackLineObj.line.x1 = x1;
stackLineObj.line.y1 = y1;
stackLineObj.line.x2 = x2;
stackLineObj.line.y2 = y2;
return stackLineObj;
}
/* Returns a pointer to an EmbLineObject. It is created on the heap. The caller is responsible for freeing the allocated memory. */
EmbLineObject* embLineObject_create(double x1, double y1, double x2, double y2)
{
EmbLineObject* heapLineObj = (EmbLineObject*)malloc(sizeof(EmbLineObject));
if(!heapLineObj) { embLog_error("emb-line.c embLineObject_create(), cannot allocate memory for heapLineObj\n"); return 0; }
heapLineObj->line.x1 = x1;
heapLineObj->line.y1 = y1;
heapLineObj->line.x2 = x2;
heapLineObj->line.y2 = y2;
return heapLineObj;
}
/**************************************************/
/* EmbLineObjectList */
/**************************************************/
EmbLineObjectList* embLineObjectList_create(EmbLineObject data)
{
EmbLineObjectList* heapLineObjList = (EmbLineObjectList*)malloc(sizeof(EmbLineObjectList));
if(!heapLineObjList) { embLog_error("emb-line.c embLineObjectList_create(), cannot allocate memory for heapLineObjList\n"); return 0; }
heapLineObjList->lineObj = data;
heapLineObjList->next = 0;
return heapLineObjList;
}
EmbLineObjectList* embLineObjectList_add(EmbLineObjectList* pointer, EmbLineObject data)
{
if(!pointer) { embLog_error("emb-line.c embLineObjectList_add(), pointer argument is null\n"); return 0; }
if(pointer->next) { embLog_error("emb-line.c embLineObjectList_add(), pointer->next should be null\n"); return 0; }
pointer->next = (EmbLineObjectList*)malloc(sizeof(EmbLineObjectList));
if(!pointer->next) { embLog_error("emb-line.c embLineObjectList_add(), cannot allocate memory for pointer->next\n"); return 0; }
pointer = pointer->next;
pointer->lineObj = data;
pointer->next = 0;
return pointer;
}
int embLineObjectList_count(EmbLineObjectList* pointer)
{
int i = 1;
if(!pointer) return 0;
while(pointer->next)
{
pointer = pointer->next;
i++;
}
return i;
}
int embLineObjectList_empty(EmbLineObjectList* pointer)
{
if(!pointer)
return 1;
return 0;
}
void embLineObjectList_free(EmbLineObjectList* pointer)
{
EmbLineObjectList* tempPointer = pointer;
EmbLineObjectList* nextPointer = 0;
while(tempPointer)
{
nextPointer = tempPointer->next;
free(tempPointer);
tempPointer = nextPointer;
}
pointer = 0;
}
/* TODO: API Cleanup: This function should use an embLine parameter, not vector1/vector2, and look like this:
embLine_normalVector(EmbLine line, EmbVector* result, int clockwise) */
/*! Finds the normalized vector perpendicular (clockwise) to the line given by v1->v2 (normal to the line) */
void embLine_normalVector(EmbVector vector1, EmbVector vector2, EmbVector* result, int clockwise)
{
double temp;
if(!result) { embLog_error("emb-line.c embLine_normalVector(), result argument is null\n"); return; }
result->X = vector2.X - vector1.X;
result->Y = vector2.Y - vector1.Y;
embVector_normalize(*result, result);
temp = result->X;
result->X = result->Y;
result->Y = -temp;
if(!clockwise)
{
result->X = -result->X;
result->Y = -result->Y;
}
}
/* TODO: API Cleanup: This is similar to the code we already have in geom-line.c, but may work well here.
Also the result has NOTHING to do with vectors. It sets a point, not a vector, even though
vector math is used internally inside this function. The function should look like this:
embLine_intersectionPoint(EmbLine line1, EmbLine line2, EmbPoint* result)
*/
/*! Finds the intersection of two lines given by v1->v2 and v3->v4 and sets the value in the result variable */
void embLine_intersectionPoint(EmbVector v1, EmbVector v2, EmbVector v3, EmbVector v4, EmbVector* result)
{
double A2 = v2.Y - v1.Y;
double B2 = v1.X - v2.X;
double C2 = A2 * v1.X + B2 * v1.Y;
double A1 = v4.Y - v3.Y;
double B1 = v3.X - v4.X;
double C1 = A1 * v3.X + B1 * v3.Y;
double det = A1 * B2 - A2 * B1;
if(!result) { embLog_error("emb-line.c embLine_intersectionPoint(), result argument is null\n"); return; }
/*TODO: The code below needs revised since division by zero can still occur */
if(det < 1e-10 && det > -1e-10)
{
result->X = -10000; /* TODO: What is significant about these numbers? Leave the point, undefined */
result->Y = -10000; /* TODO: A better solution would be to return an unsigned char(0 parallel, 1 intersecting, 2 not-intersecting) */
}
result->X = (B2 * C1 - B1 * C2) / det;
result->Y = (A1 * C2 - A2 * C1) / det;
}
/* kate: bom off; indent-mode cstyle; indent-width 4; replace-trailing-space-save on; */
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