Codebase list frogatto / HEAD src / rectangle_rotator.cpp
HEAD

Tree @HEAD (Download .tar.gz)

rectangle_rotator.cpp @HEAD — raw · history · blame 

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
#include "graphics.hpp"
#include "rectangle_rotator.hpp"
#include <math.h>
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif
#include "unit_test.hpp"

void rotate_rect(GLshort center_x, GLshort center_y, float rotation, GLshort* rect_vertexes){

	point p;
	
	float rotate_radians = (rotation * M_PI)/180;
	
	//rect r(rect_vertexes[0],rect_vertexes[1],rect_vertexes[4]-rect_vertexes[0],rect_vertexes[5]-rect_vertexes[1]);
	
	p = rotate_point_around_origin_with_offset( rect_vertexes[0], rect_vertexes[1], rotate_radians, center_x, center_y );
	rect_vertexes[0] = p.x;
	rect_vertexes[1] = p.y;
	
	p = rotate_point_around_origin_with_offset( rect_vertexes[2], rect_vertexes[3], rotate_radians, center_x, center_y );
	rect_vertexes[2] = p.x;
	rect_vertexes[3] = p.y;
	
	p = rotate_point_around_origin_with_offset( rect_vertexes[4], rect_vertexes[5], rotate_radians, center_x, center_y );
	rect_vertexes[4] = p.x;
	rect_vertexes[5] = p.y;
	
	p = rotate_point_around_origin_with_offset( rect_vertexes[6], rect_vertexes[7], rotate_radians, center_x, center_y );
	rect_vertexes[6] = p.x;
	rect_vertexes[7] = p.y;
	
}


void rotate_rect(const rect& r, GLfloat angle, GLshort* output){
	
	point offset;
	offset.x = r.x() + r.w()/2;
	offset.y = r.y() + r.h()/2;

	point p;

	p = rotate_point_around_origin_with_offset( r.x(), r.y(), angle, offset.x, offset.y );
	output[0] = p.x;
	output[1] = p.y;

	p = rotate_point_around_origin_with_offset( r.x2(), r.y(), angle, offset.x, offset.y );
	output[2] = p.x;
	output[3] = p.y;

	p = rotate_point_around_origin_with_offset( r.x2(), r.y2(), angle, offset.x, offset.y );
	output[4] = p.x;
	output[5] = p.y;

	p = rotate_point_around_origin_with_offset( r.x(), r.y2(), angle, offset.x, offset.y );
	output[6] = p.x;
	output[7] = p.y;

}

point rotate_point_around_origin_with_offset(int x1, int y1, float alpha, int u1, int v1){
	
	point beta = rotate_point_around_origin(x1 - u1, y1 - v1, alpha);
	
	beta.x += u1;
	beta.y += v1;
	
	return beta;
}

point rotate_point_around_origin(int x1, int y1, float alpha){

	point beta;
	
	/*   //we actually don't need the initial theta and radius.  This is why:
	x2 = R * (cos(theta) * cos(alpha) + sin(theta) * sin(alpha))
	y2 = R * (sin(theta) * cos(alpha) + cos(theta) * sin(alpha));
	but
	R * (cos(theta)) = x1
	R * (sin(theta)) = x2
	this collapses the above to:  */

	beta.x = x1 * cos(alpha) - y1 * sin(alpha);
	beta.y = y1 * cos(alpha) + x1 * sin(alpha);

	return beta;
}

/*UNIT_TEST(rotate_test) {
	std::cerr << "rotating_a_point \n";
	std::cerr << rotate_point_around_origin( 1000, 1000, (M_PI/2)).to_string() << "\n";  //Should be -1000,1000 
	std::cerr << rotate_point_around_origin_with_offset( 11000, 1000, (M_PI/2), 10000,0).to_string() << "\n"; //Should be 9000,1000 
	
	GLshort myOutputData[8];
	rect r(10, 10, 20, 30);
	rotate_rect(r, (M_PI*2), myOutputData);
	
	std::cerr << "Outputting point list \n";
	for(int i=0;i<8;++i){
		std::cerr << myOutputData[i] << " ";
		if(i%2){ std::cerr << "\n";}
	}
}*/


BENCHMARK(rect_rotation) {
	rect r(10, 10, 20, 30);
	GLshort output[8];
	BENCHMARK_LOOP {
		rotate_rect(r, 75, output);
	}
}