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/**
* Routines for simple 2D->2D transformations for rotated, flipped screens.
*
* XXX This code is not intel-specific. Move it into a common/utility
* someday.
*/
#include "intel_rotate.h"
#define MIN2(A, B) ( ((A) < (B)) ? (A) : (B) )
#define ABS(A) ( ((A) < 0) ? -(A) : (A) )
void
matrix23Set(struct matrix23 *m,
int m00, int m01, int m02, int m10, int m11, int m12)
{
m->m00 = m00;
m->m01 = m01;
m->m02 = m02;
m->m10 = m10;
m->m11 = m11;
m->m12 = m12;
}
/*
* Transform (x,y) coordinate by the given matrix.
*/
void
matrix23TransformCoordf(const struct matrix23 *m, float *x, float *y)
{
const float x0 = *x;
const float y0 = *y;
*x = m->m00 * x0 + m->m01 * y0 + m->m02;
*y = m->m10 * x0 + m->m11 * y0 + m->m12;
}
void
matrix23TransformCoordi(const struct matrix23 *m, int *x, int *y)
{
const int x0 = *x;
const int y0 = *y;
*x = m->m00 * x0 + m->m01 * y0 + m->m02;
*y = m->m10 * x0 + m->m11 * y0 + m->m12;
}
/*
* Transform a width and height by the given matrix.
* XXX this could be optimized quite a bit.
*/
void
matrix23TransformDistance(const struct matrix23 *m, int *xDist, int *yDist)
{
int x0 = 0, y0 = 0;
int x1 = *xDist, y1 = 0;
int x2 = 0, y2 = *yDist;
matrix23TransformCoordi(m, &x0, &y0);
matrix23TransformCoordi(m, &x1, &y1);
matrix23TransformCoordi(m, &x2, &y2);
*xDist = (x1 - x0) + (x2 - x0);
*yDist = (y1 - y0) + (y2 - y0);
if (*xDist < 0)
*xDist = -*xDist;
if (*yDist < 0)
*yDist = -*yDist;
}
/**
* Transform the rect defined by (x, y, w, h) by m.
*/
void
matrix23TransformRect(const struct matrix23 *m, int *x, int *y, int *w,
int *h)
{
int x0 = *x, y0 = *y;
int x1 = *x + *w, y1 = *y;
int x2 = *x + *w, y2 = *y + *h;
int x3 = *x, y3 = *y + *h;
matrix23TransformCoordi(m, &x0, &y0);
matrix23TransformCoordi(m, &x1, &y1);
matrix23TransformCoordi(m, &x2, &y2);
matrix23TransformCoordi(m, &x3, &y3);
*w = ABS(x1 - x0) + ABS(x2 - x1);
/**w = ABS(*w);*/
*h = ABS(y1 - y0) + ABS(y2 - y1);
/**h = ABS(*h);*/
*x = MIN2(x0, x1);
*x = MIN2(*x, x2);
*y = MIN2(y0, y1);
*y = MIN2(*y, y2);
}
/*
* Make rotation matrix for width X height screen.
*/
void
matrix23Rotate(struct matrix23 *m, int width, int height, int angle)
{
switch (angle) {
case 0:
matrix23Set(m, 1, 0, 0, 0, 1, 0);
break;
case 90:
matrix23Set(m, 0, 1, 0, -1, 0, width);
break;
case 180:
matrix23Set(m, -1, 0, width, 0, -1, height);
break;
case 270:
matrix23Set(m, 0, -1, height, 1, 0, 0);
break;
default:
/*abort() */ ;
}
}
/*
* Make flip/reflection matrix for width X height screen.
*/
void
matrix23Flip(struct matrix23 *m, int width, int height, int xflip, int yflip)
{
if (xflip) {
m->m00 = -1;
m->m01 = 0;
m->m02 = width - 1;
}
else {
m->m00 = 1;
m->m01 = 0;
m->m02 = 0;
}
if (yflip) {
m->m10 = 0;
m->m11 = -1;
m->m12 = height - 1;
}
else {
m->m10 = 0;
m->m11 = 1;
m->m12 = 0;
}
}
/*
* result = a * b
*/
void
matrix23Multiply(struct matrix23 *result,
const struct matrix23 *a, const struct matrix23 *b)
{
result->m00 = a->m00 * b->m00 + a->m01 * b->m10;
result->m01 = a->m00 * b->m01 + a->m01 * b->m11;
result->m02 = a->m00 * b->m02 + a->m01 * b->m12 + a->m02;
result->m10 = a->m10 * b->m00 + a->m11 * b->m10;
result->m11 = a->m10 * b->m01 + a->m11 * b->m11;
result->m12 = a->m10 * b->m02 + a->m11 * b->m12 + a->m12;
}
#if 000
#include <stdio.h>
int
main(int argc, char *argv[])
{
int width = 500, height = 400;
int rot;
int fx = 0, fy = 0; /* flip x and/or y ? */
int coords[4][2];
/* four corner coords to test with */
coords[0][0] = 0;
coords[0][1] = 0;
coords[1][0] = width - 1;
coords[1][1] = 0;
coords[2][0] = width - 1;
coords[2][1] = height - 1;
coords[3][0] = 0;
coords[3][1] = height - 1;
for (rot = 0; rot < 360; rot += 90) {
struct matrix23 rotate, flip, m;
int i;
printf("Rot %d, xFlip %d, yFlip %d:\n", rot, fx, fy);
/* make transformation matrix 'm' */
matrix23Rotate(&rotate, width, height, rot);
matrix23Flip(&flip, width, height, fx, fy);
matrix23Multiply(&m, &rotate, &flip);
/* xform four coords */
for (i = 0; i < 4; i++) {
int x = coords[i][0];
int y = coords[i][1];
matrix23TransformCoordi(&m, &x, &y);
printf(" %d, %d -> %d %d\n", coords[i][0], coords[i][1], x, y);
}
/* xform width, height */
{
int x = width;
int y = height;
matrix23TransformDistance(&m, &x, &y);
printf(" %d x %d -> %d x %d\n", width, height, x, y);
}
/* xform rect */
{
int x = 50, y = 10, w = 200, h = 100;
matrix23TransformRect(&m, &x, &y, &w, &h);
printf(" %d,%d %d x %d -> %d, %d %d x %d\n", 50, 10, 200, 100,
x, y, w, h);
}
}
return 0;
}
#endif
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