mirror of
https://github.com/Valeh2012/PersonalVotingMachine
synced 2024-11-25 18:31:00 +02:00
347 lines
7.2 KiB
C
347 lines
7.2 KiB
C
/*
|
|
|
|
u8g22_polygon.c
|
|
|
|
*/
|
|
|
|
|
|
#include "u8g2.h"
|
|
|
|
|
|
|
|
|
|
/*===========================================*/
|
|
/* local definitions */
|
|
|
|
typedef int16_t pg_word_t;
|
|
|
|
|
|
struct pg_point_struct
|
|
{
|
|
pg_word_t x;
|
|
pg_word_t y;
|
|
};
|
|
|
|
typedef struct _pg_struct pg_struct; /* forward declaration */
|
|
|
|
struct pg_edge_struct
|
|
{
|
|
pg_word_t x_direction; /* 1, if x2 is greater than x1, -1 otherwise */
|
|
pg_word_t height;
|
|
pg_word_t current_x_offset;
|
|
pg_word_t error_offset;
|
|
|
|
/* --- line loop --- */
|
|
pg_word_t current_y;
|
|
pg_word_t max_y;
|
|
pg_word_t current_x;
|
|
pg_word_t error;
|
|
|
|
/* --- outer loop --- */
|
|
uint8_t (*next_idx_fn)(pg_struct *pg, uint8_t i);
|
|
uint8_t curr_idx;
|
|
};
|
|
|
|
/* maximum number of points in the polygon */
|
|
/* can be redefined, but highest possible value is 254 */
|
|
#define PG_MAX_POINTS 6
|
|
|
|
/* index numbers for the pge structures below */
|
|
#define PG_LEFT 0
|
|
#define PG_RIGHT 1
|
|
|
|
|
|
struct _pg_struct
|
|
{
|
|
struct pg_point_struct list[PG_MAX_POINTS];
|
|
uint8_t cnt;
|
|
uint8_t is_min_y_not_flat;
|
|
pg_word_t total_scan_line_cnt;
|
|
struct pg_edge_struct pge[2]; /* left and right line draw structures */
|
|
};
|
|
|
|
|
|
/*===========================================*/
|
|
/* procedures, which should not be inlined (save as much flash ROM as possible */
|
|
|
|
#define PG_NOINLINE U8G2_NOINLINE
|
|
|
|
static uint8_t pge_Next(struct pg_edge_struct *pge) PG_NOINLINE;
|
|
static uint8_t pg_inc(pg_struct *pg, uint8_t i) PG_NOINLINE;
|
|
static uint8_t pg_dec(pg_struct *pg, uint8_t i) PG_NOINLINE;
|
|
static void pg_expand_min_y(pg_struct *pg, pg_word_t min_y, uint8_t pge_idx) PG_NOINLINE;
|
|
static void pg_line_init(pg_struct * const pg, uint8_t pge_index) PG_NOINLINE;
|
|
|
|
/*===========================================*/
|
|
/* line draw algorithm */
|
|
|
|
static uint8_t pge_Next(struct pg_edge_struct *pge)
|
|
{
|
|
if ( pge->current_y >= pge->max_y )
|
|
return 0;
|
|
|
|
pge->current_x += pge->current_x_offset;
|
|
pge->error += pge->error_offset;
|
|
if ( pge->error > 0 )
|
|
{
|
|
pge->current_x += pge->x_direction;
|
|
pge->error -= pge->height;
|
|
}
|
|
|
|
pge->current_y++;
|
|
return 1;
|
|
}
|
|
|
|
/* assumes y2 > y1 */
|
|
static void pge_Init(struct pg_edge_struct *pge, pg_word_t x1, pg_word_t y1, pg_word_t x2, pg_word_t y2)
|
|
{
|
|
pg_word_t dx = x2 - x1;
|
|
pg_word_t width;
|
|
|
|
pge->height = y2 - y1;
|
|
pge->max_y = y2;
|
|
pge->current_y = y1;
|
|
pge->current_x = x1;
|
|
|
|
if ( dx >= 0 )
|
|
{
|
|
pge->x_direction = 1;
|
|
width = dx;
|
|
pge->error = 0;
|
|
}
|
|
else
|
|
{
|
|
pge->x_direction = -1;
|
|
width = -dx;
|
|
pge->error = 1 - pge->height;
|
|
}
|
|
|
|
pge->current_x_offset = dx / pge->height;
|
|
pge->error_offset = width % pge->height;
|
|
}
|
|
|
|
/*===========================================*/
|
|
/* convex polygon algorithm */
|
|
|
|
static uint8_t pg_inc(pg_struct *pg, uint8_t i)
|
|
{
|
|
i++;
|
|
if ( i >= pg->cnt )
|
|
i = 0;
|
|
return i;
|
|
}
|
|
|
|
static uint8_t pg_dec(pg_struct *pg, uint8_t i)
|
|
{
|
|
i--;
|
|
if ( i >= pg->cnt )
|
|
i = pg->cnt-1;
|
|
return i;
|
|
}
|
|
|
|
static void pg_expand_min_y(pg_struct *pg, pg_word_t min_y, uint8_t pge_idx)
|
|
{
|
|
uint8_t i = pg->pge[pge_idx].curr_idx;
|
|
for(;;)
|
|
{
|
|
i = pg->pge[pge_idx].next_idx_fn(pg, i);
|
|
if ( pg->list[i].y != min_y )
|
|
break;
|
|
pg->pge[pge_idx].curr_idx = i;
|
|
}
|
|
}
|
|
|
|
static uint8_t pg_prepare(pg_struct *pg)
|
|
{
|
|
pg_word_t max_y;
|
|
pg_word_t min_y;
|
|
uint8_t i;
|
|
|
|
/* setup the next index procedures */
|
|
pg->pge[PG_RIGHT].next_idx_fn = pg_inc;
|
|
pg->pge[PG_LEFT].next_idx_fn = pg_dec;
|
|
|
|
/* search for highest and lowest point */
|
|
max_y = pg->list[0].y;
|
|
min_y = pg->list[0].y;
|
|
pg->pge[PG_LEFT].curr_idx = 0;
|
|
for( i = 1; i < pg->cnt; i++ )
|
|
{
|
|
if ( max_y < pg->list[i].y )
|
|
{
|
|
max_y = pg->list[i].y;
|
|
}
|
|
if ( min_y > pg->list[i].y )
|
|
{
|
|
pg->pge[PG_LEFT].curr_idx = i;
|
|
min_y = pg->list[i].y;
|
|
}
|
|
}
|
|
|
|
/* calculate total number of scan lines */
|
|
pg->total_scan_line_cnt = max_y;
|
|
pg->total_scan_line_cnt -= min_y;
|
|
|
|
/* exit if polygon height is zero */
|
|
if ( pg->total_scan_line_cnt == 0 )
|
|
return 0;
|
|
|
|
/* if the minimum y side is flat, try to find the lowest and highest x points */
|
|
pg->pge[PG_RIGHT].curr_idx = pg->pge[PG_LEFT].curr_idx;
|
|
pg_expand_min_y(pg, min_y, PG_RIGHT);
|
|
pg_expand_min_y(pg, min_y, PG_LEFT);
|
|
|
|
/* check if the min side is really flat (depends on the x values) */
|
|
pg->is_min_y_not_flat = 1;
|
|
if ( pg->list[pg->pge[PG_LEFT].curr_idx].x != pg->list[pg->pge[PG_RIGHT].curr_idx].x )
|
|
{
|
|
pg->is_min_y_not_flat = 0;
|
|
}
|
|
else
|
|
{
|
|
pg->total_scan_line_cnt--;
|
|
if ( pg->total_scan_line_cnt == 0 )
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static void pg_hline(pg_struct *pg, u8g2_t *u8g2)
|
|
{
|
|
pg_word_t x1, x2, y;
|
|
x1 = pg->pge[PG_LEFT].current_x;
|
|
x2 = pg->pge[PG_RIGHT].current_x;
|
|
y = pg->pge[PG_RIGHT].current_y;
|
|
|
|
if ( y < 0 )
|
|
return;
|
|
if ( y >= u8g2_GetDisplayHeight(u8g2) ) // does not work for 256x64 display???
|
|
return;
|
|
if ( x1 < x2 )
|
|
{
|
|
if ( x2 < 0 )
|
|
return;
|
|
if ( x1 >= u8g2_GetDisplayWidth(u8g2) )
|
|
return;
|
|
if ( x1 < 0 )
|
|
x1 = 0;
|
|
if ( x2 >= u8g2_GetDisplayWidth(u8g2) )
|
|
x2 = u8g2_GetDisplayWidth(u8g2);
|
|
u8g2_DrawHLine(u8g2, x1, y, x2 - x1);
|
|
}
|
|
else
|
|
{
|
|
if ( x1 < 0 )
|
|
return;
|
|
if ( x2 >= u8g2_GetDisplayWidth(u8g2) )
|
|
return;
|
|
if ( x2 < 0 )
|
|
x1 = 0;
|
|
if ( x1 >= u8g2_GetDisplayWidth(u8g2) )
|
|
x1 = u8g2_GetDisplayWidth(u8g2);
|
|
u8g2_DrawHLine(u8g2, x2, y, x1 - x2);
|
|
}
|
|
}
|
|
|
|
static void pg_line_init(pg_struct * const pg, uint8_t pge_index)
|
|
{
|
|
struct pg_edge_struct *pge = pg->pge+pge_index;
|
|
uint8_t idx;
|
|
pg_word_t x1;
|
|
pg_word_t y1;
|
|
pg_word_t x2;
|
|
pg_word_t y2;
|
|
|
|
idx = pge->curr_idx;
|
|
y1 = pg->list[idx].y;
|
|
x1 = pg->list[idx].x;
|
|
idx = pge->next_idx_fn(pg, idx);
|
|
y2 = pg->list[idx].y;
|
|
x2 = pg->list[idx].x;
|
|
pge->curr_idx = idx;
|
|
|
|
pge_Init(pge, x1, y1, x2, y2);
|
|
}
|
|
|
|
static void pg_exec(pg_struct *pg, u8g2_t *u8g2)
|
|
{
|
|
pg_word_t i = pg->total_scan_line_cnt;
|
|
|
|
/* first line is skipped if the min y line is not flat */
|
|
pg_line_init(pg, PG_LEFT);
|
|
pg_line_init(pg, PG_RIGHT);
|
|
|
|
if ( pg->is_min_y_not_flat != 0 )
|
|
{
|
|
pge_Next(&(pg->pge[PG_LEFT]));
|
|
pge_Next(&(pg->pge[PG_RIGHT]));
|
|
}
|
|
|
|
do
|
|
{
|
|
pg_hline(pg, u8g2);
|
|
while ( pge_Next(&(pg->pge[PG_LEFT])) == 0 )
|
|
{
|
|
pg_line_init(pg, PG_LEFT);
|
|
}
|
|
while ( pge_Next(&(pg->pge[PG_RIGHT])) == 0 )
|
|
{
|
|
pg_line_init(pg, PG_RIGHT);
|
|
}
|
|
i--;
|
|
} while( i > 0 );
|
|
}
|
|
|
|
/*===========================================*/
|
|
/* API procedures */
|
|
|
|
static void pg_ClearPolygonXY(pg_struct *pg)
|
|
{
|
|
pg->cnt = 0;
|
|
}
|
|
|
|
static void pg_AddPolygonXY(pg_struct *pg, int16_t x, int16_t y)
|
|
{
|
|
if ( pg->cnt < PG_MAX_POINTS )
|
|
{
|
|
pg->list[pg->cnt].x = x;
|
|
pg->list[pg->cnt].y = y;
|
|
pg->cnt++;
|
|
}
|
|
}
|
|
|
|
static void pg_DrawPolygon(pg_struct *pg, u8g2_t *u8g2)
|
|
{
|
|
if ( pg_prepare(pg) == 0 )
|
|
return;
|
|
pg_exec(pg, u8g2);
|
|
}
|
|
|
|
pg_struct u8g2_pg;
|
|
|
|
void u8g2_ClearPolygonXY(void)
|
|
{
|
|
pg_ClearPolygonXY(&u8g2_pg);
|
|
}
|
|
|
|
void u8g2_AddPolygonXY(U8X8_UNUSED u8g2_t *u8g2, int16_t x, int16_t y)
|
|
{
|
|
pg_AddPolygonXY(&u8g2_pg, x, y);
|
|
}
|
|
|
|
void u8g2_DrawPolygon(u8g2_t *u8g2)
|
|
{
|
|
pg_DrawPolygon(&u8g2_pg, u8g2);
|
|
}
|
|
|
|
void u8g2_DrawTriangle(u8g2_t *u8g2, int16_t x0, int16_t y0, int16_t x1, int16_t y1, int16_t x2, int16_t y2)
|
|
{
|
|
u8g2_ClearPolygonXY();
|
|
u8g2_AddPolygonXY(u8g2, x0, y0);
|
|
u8g2_AddPolygonXY(u8g2, x1, y1);
|
|
u8g2_AddPolygonXY(u8g2, x2, y2);
|
|
u8g2_DrawPolygon(u8g2);
|
|
}
|
|
|