Lockpick_RCM/bdk/libs/lvgl/lv_draw/lv_draw_triangle.c
2020-06-26 14:17:06 -06:00

169 lines
4.5 KiB
C

/**
* @file lv_draw_triangle.c
*
*/
/*********************
* INCLUDES
*********************/
#include "lv_draw_triangle.h"
#include "../lv_misc/lv_math.h"
/*********************
* DEFINES
*********************/
/**********************
* TYPEDEFS
**********************/
/**********************
* STATIC PROTOTYPES
**********************/
/**********************
* STATIC VARIABLES
**********************/
static void point_swap(lv_point_t * p1, lv_point_t * p2);
/**********************
* MACROS
**********************/
/**********************
* GLOBAL FUNCTIONS
**********************/
#if USE_LV_TRIANGLE != 0
/**
*
* @param points pointer to an array with 3 points
* @param mask the triangle will be drawn only in this mask
* @param color color of the triangle
*/
void lv_draw_triangle(const lv_point_t * points, const lv_area_t * mask, lv_color_t color)
{
lv_point_t tri[3];
memcpy(tri, points, sizeof(tri));
/*Sort the vertices according to their y coordinate (0: y max, 1: y mid, 2:y min)*/
if(tri[1].y < tri[0].y) point_swap(&tri[1], &tri[0]);
if(tri[2].y < tri[1].y) point_swap(&tri[2], &tri[1]);
if(tri[1].y < tri[0].y) point_swap(&tri[1], &tri[0]);
/*Return is the triangle is degenerated*/
if(tri[0].x == tri[1].x && tri[0].y == tri[1].y) return;
if(tri[1].x == tri[2].x && tri[1].y == tri[2].y) return;
if(tri[0].x == tri[2].x && tri[0].y == tri[2].y) return;
if(tri[0].x == tri[1].x && tri[1].x == tri[2].x) return;
if(tri[0].y == tri[1].y && tri[1].y == tri[2].y) return;
/*Draw the triangle*/
lv_point_t edge1;
lv_coord_t dx1 = LV_MATH_ABS(tri[0].x - tri[1].x);
lv_coord_t sx1 = tri[0].x < tri[1].x ? 1 : -1;
lv_coord_t dy1 = LV_MATH_ABS(tri[0].y - tri[1].y);
lv_coord_t sy1 = tri[0].y < tri[1].y ? 1 : -1;
lv_coord_t err1 = (dx1 > dy1 ? dx1 : -dy1) / 2;
lv_coord_t err_tmp1;
lv_point_t edge2;
lv_coord_t dx2 = LV_MATH_ABS(tri[0].x - tri[2].x);
lv_coord_t sx2 = tri[0].x < tri[2].x ? 1 : -1;
lv_coord_t dy2 = LV_MATH_ABS(tri[0].y - tri[2].y);
lv_coord_t sy2 = tri[0].y < tri[2].y ? 1 : -1;
lv_coord_t err2 = (dx1 > dy2 ? dx2 : -dy2) / 2;
lv_coord_t err_tmp2;
lv_coord_t y1_tmp;
lv_coord_t y2_tmp;
edge1.x = tri[0].x;
edge1.y = tri[0].y;
edge2.x = tri[0].x;
edge2.y = tri[0].y;
lv_area_t act_area;
lv_area_t draw_area;
while(1) {
act_area.x1 = edge1.x;
act_area.x2 = edge2.x ;
act_area.y1 = edge1.y;
act_area.y2 = edge2.y ;
draw_area.x1 = LV_MATH_MIN(act_area.x1, act_area.x2);
draw_area.x2 = LV_MATH_MAX(act_area.x1, act_area.x2);
draw_area.y1 = LV_MATH_MIN(act_area.y1, act_area.y2);
draw_area.y2 = LV_MATH_MAX(act_area.y1, act_area.y2);
draw_area.x2--; /*Do not draw most right pixel because it will be drawn by the adjacent triangle*/
fill_fp(&draw_area, mask, color, LV_OPA_50);
/*Calc. the next point of edge1*/
y1_tmp = edge1.y;
do {
if(edge1.x == tri[1].x && edge1.y == tri[1].y) {
dx1 = LV_MATH_ABS(tri[1].x - tri[2].x);
sx1 = tri[1].x < tri[2].x ? 1 : -1;
dy1 = LV_MATH_ABS(tri[1].y - tri[2].y);
sy1 = tri[1].y < tri[2].y ? 1 : -1;
err1 = (dx1 > dy1 ? dx1 : -dy1) / 2;
} else if(edge1.x == tri[2].x && edge1.y == tri[2].y) return;
err_tmp1 = err1;
if(err_tmp1 > -dx1) {
err1 -= dy1;
edge1.x += sx1;
}
if(err_tmp1 < dy1) {
err1 += dx1;
edge1.y += sy1;
}
} while(edge1.y == y1_tmp);
/*Calc. the next point of edge2*/
y2_tmp = edge2.y;
do {
if(edge2.x == tri[2].x && edge2.y == tri[2].y) return;
err_tmp2 = err2;
if(err_tmp2 > -dx2) {
err2 -= dy2;
edge2.x += sx2;
}
if(err_tmp2 < dy2) {
err2 += dx2;
edge2.y += sy2;
}
} while(edge2.y == y2_tmp);
}
}
#endif
/**********************
* STATIC FUNCTIONS
**********************/
#if USE_LV_TRIANGLE != 0
/**
* Swap two points
* p1 pointer to the first point
* p2 pointer to the second point
*/
static void point_swap(lv_point_t * p1, lv_point_t * p2)
{
lv_point_t tmp;
tmp.x = p1->x;
tmp.y = p1->y;
p1->x = p2->x;
p1->y = p2->y;
p2->x = tmp.x;
p2->y = tmp.y;
}
#endif