void nxgl_circlepts(FAR const struct nxgl_point_s *center, nxgl_coord_t radius,
FAR struct nxgl_point_s *circle)
{
nxgl_coord_t xoffs;
nxgl_coord_t yoffs;
/* 0, 90, 180, and 270 degrees are the easiest */
circle[POINT_0p0].x = center->x + radius;
circle[POINT_0p0].y = center->y;
circle[POINT_90p0].x = center->x;
circle[POINT_90p0].y = center->y + radius;
circle[POINT_180p0].x = center->x - radius;
circle[POINT_180p0].y = center->y;
circle[POINT_270p0].x = center->x;
circle[POINT_270p0].y = center->y - radius;
/* Now 22.5, 67.5, 112.5, 157.5, 202.5, 247.5, 292.5, and 337.5 */
xoffs = b16toi(b16muli(COS_22p5, radius) + b16HALF);
yoffs = b16toi(b16muli(SIN_22p5, radius) + b16HALF);
circle[POINT_22p5].x = center->x + xoffs;
circle[POINT_22p5].y = center->y + yoffs;
circle[POINT_157p5].x = center->x - xoffs;
circle[POINT_157p5].y = center->y + yoffs;
circle[POINT_202p5].x = center->x - xoffs;
circle[POINT_202p5].y = center->y - yoffs;
circle[POINT_337p5].x = center->x + xoffs;
circle[POINT_337p5].y = center->y - yoffs;
circle[POINT_67p5].x = center->x + yoffs;
circle[POINT_67p5].y = center->y + xoffs;
circle[POINT_112p5].x = center->x - yoffs;
circle[POINT_112p5].y = center->y + xoffs;
circle[POINT_247p5].x = center->x - yoffs;
circle[POINT_247p5].y = center->y - xoffs;
circle[POINT_292p5].x = center->x + yoffs;
circle[POINT_292p5].y = center->y - xoffs;
/* Finally, 45.0, 135.0, 225.0, 315.0 */
xoffs = b16toi(b16muli(COS_45p0, radius) + b16HALF);
circle[POINT_45p0].x = center->x + xoffs;
circle[POINT_45p0].y = center->y + xoffs;
circle[POINT_135p0].x = center->x - xoffs;
circle[POINT_135p0].y = center->y + xoffs;
circle[POINT_225p0].x = center->x - xoffs;
circle[POINT_225p0].y = center->y - xoffs;
circle[POINT_315p0].x = center->x + xoffs;
circle[POINT_315p0].y = center->y - xoffs;
}
void nxgl_yuv2rgb(uint8_t y, uint8_t u, uint8_t v,
uint8_t *r, uint8_t *g, uint8_t *b)
{
b16_t vm128 = itob16(v) - b16_128P0;
b16_t um128 = itob16(u) - b16_128P0;
/* Per the JFIF specification:
*
* R = Y + 1.40200 * (V - 128.0)
* G = Y - 0.34414 * (U - 128.0) - 0.71414 * (V - 128.0)
* B = Y + 1.77200 * (U - 128.0)
*/
*r = (uint8_t)b16toi(itob16(y) + b16muli(b16_1P402, vm128));
*g = (uint8_t)b16toi(itob16(y) - b16muli(b16_P3441, um128) - b16muli(b16_P7141, vm128));
*b = (uint8_t)b16toi(itob16(y) + b16muli(b16_1P772, um128));
}
void nxgl_rgb2yuv(uint8_t r, uint8_t g, uint8_t b,
uint8_t *y, uint8_t *u, uint8_t *v)
{
/* Per the JFIF specification:
*
* Y = (0.2990 * R) + (0.5870 * G) + (0.1140 * B)
* U = 128 - (0.1687 * R) - (0.3313 * G) + (0.5000 * B)
* V = 128 + (0.5000 * R) - (0.4187 * G) - (0.0813 * B);
*/
*y = (uint8_t)b16toi(b16muli(b16_P2990, r) + b16muli(b16_P5870, g) + b16muli(b16_P1140, b));
*u = (uint8_t)b16toi(b16_128P0 - b16muli(b16_P1687, r) - b16muli(b16_P3313, g) + b16muli(b16_P5000, b));
*v = (uint8_t)b16toi(b16_128P0 + b16muli(b16_P5000, r) - b16muli(b16_P4187, g) - b16muli(b16_P0813, b));
}
void nxgl_circletraps(FAR const struct nxgl_point_s *center, nxgl_coord_t radius,
FAR struct nxgl_trapezoid_s *circle)
{
nxgl_coord_t xoffs;
nxgl_coord_t yoffs;
circle[0].top.x1 = itob16(center->x);
circle[0].top.x2 = circle[0].top.x1;
circle[0].top.y = center->y - radius;
circle[7].bot.x1 = circle[0].top.x1;
circle[7].bot.x2 = circle[0].top.x1;
circle[7].bot.y = center->y + radius;
circle[3].bot.x1 = itob16(center->x - radius);
circle[3].bot.x2 = itob16(center->x + radius);
circle[3].bot.y = center->y;
circle[4].top.x1 = circle[3].bot.x1;
circle[4].top.x2 = circle[3].bot.x2;
circle[4].top.y = circle[3].bot.y;
/* Now 22.5, 67.5, 112.5, 157.5, 202.5, 247.5, 292.5, and 337.5 */
xoffs = b16toi(b16muli(COS_22p5, radius) + b16HALF);
yoffs = b16toi(b16muli(SIN_22p5, radius) + b16HALF);
circle[2].bot.x1 = itob16(center->x - xoffs);
circle[2].bot.x2 = itob16(center->x + xoffs);
circle[2].bot.y = center->y - yoffs;
circle[3].top.x1 = circle[2].bot.x1;
circle[3].top.x2 = circle[2].bot.x2;
circle[3].top.y = circle[2].bot.y;
circle[4].bot.x1 = circle[2].bot.x1;
circle[4].bot.x2 = circle[2].bot.x2;
circle[4].bot.y = center->y + yoffs;
circle[5].top.x1 = circle[4].bot.x1;
circle[5].top.x2 = circle[4].bot.x2;
circle[5].top.y = circle[4].bot.y;
circle[0].bot.x1 = itob16(center->x - yoffs);
circle[0].bot.x2 = itob16(center->x + yoffs);
circle[0].bot.y = center->y - xoffs;
circle[1].top.x1 = circle[0].bot.x1;
circle[1].top.x2 = circle[0].bot.x2;
circle[1].top.y = circle[0].bot.y;
circle[6].bot.x1 = circle[1].top.x1;
circle[6].bot.x2 = circle[1].top.x2;
circle[6].bot.y = center->y + xoffs;
circle[7].top.x1 = circle[6].bot.x1;
circle[7].top.x2 = circle[6].bot.x2;
circle[7].top.y = circle[6].bot.y;
/* Finally, 45.0, 135.0, 225.0, 315.0 */
xoffs = b16toi(b16muli(COS_45p0, radius) + b16HALF);
circle[1].bot.x1 = itob16(center->x - xoffs);
circle[1].bot.x2 = itob16(center->x + xoffs);
circle[1].bot.y = center->y - xoffs;
circle[2].top.x1 = circle[1].bot.x1;
circle[2].top.x2 = circle[1].bot.x2;
circle[2].top.y = circle[1].bot.y;
circle[5].bot.x1 = circle[1].bot.x1;
circle[5].bot.x2 = circle[1].bot.x2;
circle[5].bot.y = center->y + xoffs;
circle[6].top.x1 = circle[5].bot.x1;
circle[6].top.x2 = circle[5].bot.x2;
circle[6].top.y = circle[5].bot.y;
}
