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hekate/bdk/libs/lvgl/lv_draw/lv_draw_vbasic.c

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[Nyx] Introducing hekate GUI, named Nyx! Version 0.8.0. Expect dragons!
2019-06-30 01:03:00 +00:00
/**
* @file lv_vdraw.c
*
*/
#include "lv_draw_vbasic.h"
#include <stdint.h>
#include <string.h>
#include "../lv_hal/lv_hal_disp.h"
#include "../lv_misc/lv_area.h"
#include "../lv_misc/lv_font.h"
#include "../lv_misc/lv_color.h"
#include "../lv_misc/lv_log.h"
#if LV_VDB_SIZE != 0
#include <stddef.h>
#include "../lv_core/lv_vdb.h"
#include "lv_draw.h"
/*********************
* INCLUDES
*********************/
/*********************
* DEFINES
*********************/
#define VFILL_HW_ACC_SIZE_LIMIT 50 /*Always fill < 50 px with 'sw_color_fill' because of the hw. init overhead*/
#ifndef LV_ATTRIBUTE_MEM_ALIGN
#define LV_ATTRIBUTE_MEM_ALIGN
#endif
/**********************
* TYPEDEFS
**********************/
/**********************
* STATIC PROTOTYPES
**********************/
static void sw_mem_blend(lv_color_t * dest, const lv_color_t * src, uint32_t length, lv_opa_t opa);
static void sw_color_fill(lv_area_t * mem_area, lv_color_t * mem, const lv_area_t * fill_area, lv_color_t color, lv_opa_t opa);
#if LV_COLOR_SCREEN_TRANSP
static inline lv_color_t color_mix_2_alpha(lv_color_t bg_color, lv_opa_t bg_opa, lv_color_t fg_color, lv_opa_t fg_opa);
#endif
/**********************
* STATIC VARIABLES
**********************/
/**********************
* MACROS
**********************/
/**********************
* GLOBAL FUNCTIONS
**********************/
/**
* Put a pixel in the Virtual Display Buffer
* @param x pixel x coordinate
* @param y pixel y coordinate
* @param mask_p fill only on this mask (truncated to VDB area)
* @param color pixel color
* @param opa opacity of the area (0..255)
*/
void lv_vpx(lv_coord_t x, lv_coord_t y, const lv_area_t * mask_p, lv_color_t color, lv_opa_t opa)
{
if(opa < LV_OPA_MIN) return;
if(opa > LV_OPA_MAX) opa = LV_OPA_COVER;
lv_vdb_t * vdb_p = lv_vdb_get();
if(!vdb_p) {
LV_LOG_WARN("Invalid VDB pointer");
return;
}
/*Pixel out of the mask*/
if(x < mask_p->x1 || x > mask_p->x2 ||
y < mask_p->y1 || y > mask_p->y2) {
return;
}
uint32_t vdb_width = lv_area_get_width(&vdb_p->area);
/*Make the coordinates relative to VDB*/
x -= vdb_p->area.x1;
y -= vdb_p->area.y1;
lv_disp_t * disp = lv_disp_get_active();
if(disp->driver.vdb_wr) {
disp->driver.vdb_wr((uint8_t *)vdb_p->buf, vdb_width, x, y, color, opa);
} else {
lv_color_t * vdb_px_p = vdb_p->buf + y * vdb_width + x;
#if LV_COLOR_SCREEN_TRANSP == 0
if(opa == LV_OPA_COVER) {
*vdb_px_p = color;
} else {
*vdb_px_p = lv_color_mix(color, *vdb_px_p, opa);
}
#else
*vdb_px_p = color_mix_2_alpha(*vdb_px_p, (*vdb_px_p).alpha, color, opa);
#endif
}
}
/**
* Fill an area in the Virtual Display Buffer
* @param cords_p coordinates of the area to fill
* @param mask_p fill only o this mask (truncated to VDB area)
* @param color fill color
* @param opa opacity of the area (0..255)
*/
void lv_vfill(const lv_area_t * cords_p, const lv_area_t * mask_p,
lv_color_t color, lv_opa_t opa)
{
if(opa < LV_OPA_MIN) return;
if(opa > LV_OPA_MAX) opa = LV_OPA_COVER;
lv_area_t res_a;
bool union_ok;
lv_vdb_t * vdb_p = lv_vdb_get();
if(!vdb_p) {
LV_LOG_WARN("Invalid VDB pointer");
return;
}
/*Get the union of cord and mask*/
/* The mask is already truncated to the vdb size
* in 'lv_refr_area_with_vdb' function */
union_ok = lv_area_intersect(&res_a, cords_p, mask_p);
/*If there are common part of the three area then draw to the vdb*/
if(union_ok == false) return;
lv_area_t vdb_rel_a; /*Stores relative coordinates on vdb*/
vdb_rel_a.x1 = res_a.x1 - vdb_p->area.x1;
vdb_rel_a.y1 = res_a.y1 - vdb_p->area.y1;
vdb_rel_a.x2 = res_a.x2 - vdb_p->area.x1;
vdb_rel_a.y2 = res_a.y2 - vdb_p->area.y1;
lv_color_t * vdb_buf_tmp = vdb_p->buf;
uint32_t vdb_width = lv_area_get_width(&vdb_p->area);
/*Move the vdb_tmp to the first row*/
vdb_buf_tmp += vdb_width * vdb_rel_a.y1;
#if USE_LV_GPU
static LV_ATTRIBUTE_MEM_ALIGN lv_color_t color_array_tmp[LV_HOR_RES]; /*Used by 'lv_disp_mem_blend'*/
static lv_coord_t last_width = -1;
lv_coord_t w = lv_area_get_width(&vdb_rel_a);
/*Don't use hw. acc. for every small fill (because of the init overhead)*/
if(w < VFILL_HW_ACC_SIZE_LIMIT) {
sw_color_fill(&vdb_p->area, vdb_p->buf, &vdb_rel_a, color, opa);
}
/*Not opaque fill*/
else if(opa == LV_OPA_COVER) {
/*Use hw fill if present*/
if(lv_disp_is_mem_fill_supported()) {
lv_coord_t row;
for(row = vdb_rel_a.y1; row <= vdb_rel_a.y2; row++) {
lv_disp_mem_fill(&vdb_buf_tmp[vdb_rel_a.x1], w, color);
vdb_buf_tmp += vdb_width;
}
}
/*Use hw blend if present and the area is not too small*/
else if(lv_area_get_height(&vdb_rel_a) > VFILL_HW_ACC_SIZE_LIMIT &&
lv_disp_is_mem_blend_supported()) {
/*Fill a one line sized buffer with a color and blend this later*/
if(color_array_tmp[0].full != color.full || last_width != w) {
uint16_t i;
for(i = 0; i < w; i++) {
color_array_tmp[i].full = color.full;
}
last_width = w;
}
/*Blend the filled line to every line VDB line-by-line*/
lv_coord_t row;
for(row = vdb_rel_a.y1; row <= vdb_rel_a.y2; row++) {
lv_disp_mem_blend(&vdb_buf_tmp[vdb_rel_a.x1], color_array_tmp, w, opa);
vdb_buf_tmp += vdb_width;
}
}
/*Else use sw fill if no better option*/
else {
sw_color_fill(&vdb_p->area, vdb_p->buf, &vdb_rel_a, color, opa);
}
}
/*Fill with opacity*/
else {
/*Use hw blend if present*/
if(lv_disp_is_mem_blend_supported()) {
if(color_array_tmp[0].full != color.full || last_width != w) {
uint16_t i;
for(i = 0; i < w; i++) {
color_array_tmp[i].full = color.full;
}
last_width = w;
}
lv_coord_t row;
for(row = vdb_rel_a.y1; row <= vdb_rel_a.y2; row++) {
lv_disp_mem_blend(&vdb_buf_tmp[vdb_rel_a.x1], color_array_tmp, w, opa);
vdb_buf_tmp += vdb_width;
}
}
/*Use sw fill with opa if no better option*/
else {
sw_color_fill(&vdb_p->area, vdb_p->buf, &vdb_rel_a, color, opa);
}
}
#else
sw_color_fill(&vdb_p->area, vdb_p->buf, &vdb_rel_a, color, opa);
#endif
}
/**
* Draw a letter in the Virtual Display Buffer
* @param pos_p left-top coordinate of the latter
* @param mask_p the letter will be drawn only on this area (truncated to VDB area)
* @param font_p pointer to font
* @param letter a letter to draw
* @param color color of letter
* @param opa opacity of letter (0..255)
*/
void lv_vletter(const lv_point_t * pos_p, const lv_area_t * mask_p,
const lv_font_t * font_p, uint32_t letter,
lv_color_t color, lv_opa_t opa)
{
const uint8_t bpp1_opa_table[2] = {0, 255}; /*Opacity mapping with bpp = 1 (Just for compatibility)*/
const uint8_t bpp2_opa_table[4] = {0, 85, 170, 255}; /*Opacity mapping with bpp = 2*/
const uint8_t bpp4_opa_table[16] = {0, 17, 34, 51, /*Opacity mapping with bpp = 4*/
68, 85, 102, 119,
136, 153, 170, 187,
204, 221, 238, 255
};
if(opa < LV_OPA_MIN) return;
if(opa > LV_OPA_MAX) opa = LV_OPA_COVER;
if(font_p == NULL) {
LV_LOG_WARN("Font: character's bitmap not found");
return;
}
lv_coord_t pos_x = pos_p->x;
lv_coord_t pos_y = pos_p->y;
uint8_t letter_w = lv_font_get_real_width(font_p, letter);
uint8_t letter_h = lv_font_get_height(font_p);
uint8_t bpp = lv_font_get_bpp(font_p, letter); /*Bit per pixel (1,2, 4 or 8)*/
const uint8_t * bpp_opa_table;
uint8_t mask_init;
uint8_t mask;
if(lv_font_is_monospace(font_p, letter)) {
pos_x += (lv_font_get_width(font_p, letter) - letter_w) / 2;
}
switch(bpp) {
case 1:
bpp_opa_table = bpp1_opa_table;
mask_init = 0x80;
break;
case 2:
bpp_opa_table = bpp2_opa_table;
mask_init = 0xC0;
break;
case 4:
bpp_opa_table = bpp4_opa_table;
mask_init = 0xF0;
break;
case 8:
bpp_opa_table = NULL;
mask_init = 0xFF;
break; /*No opa table, pixel value will be used directly*/
default:
return; /*Invalid bpp. Can't render the letter*/
}
const uint8_t * map_p = lv_font_get_bitmap(font_p, letter);
if(map_p == NULL) return;
/*If the letter is completely out of mask don't draw it */
if(pos_x + letter_w < mask_p->x1 || pos_x > mask_p->x2 ||
pos_y + letter_h < mask_p->y1 || pos_y > mask_p->y2) return;
lv_vdb_t * vdb_p = lv_vdb_get();
if(!vdb_p) {
LV_LOG_WARN("Invalid VDB pointer");
return;
}
lv_coord_t vdb_width = lv_area_get_width(&vdb_p->area);
lv_color_t * vdb_buf_tmp = vdb_p->buf;
lv_coord_t col, row;
uint8_t col_bit;
uint8_t col_byte_cnt;
uint8_t width_byte_scr = letter_w >> 3; /*Width in bytes (on the screen finally) (e.g. w = 11 -> 2 bytes wide)*/
if(letter_w & 0x7) width_byte_scr++;
uint8_t width_byte_bpp = (letter_w * bpp) >> 3; /*Letter width in byte. Real width in the font*/
if((letter_w * bpp) & 0x7) width_byte_bpp++;
/* Calculate the col/row start/end on the map*/
lv_coord_t col_start = pos_x >= mask_p->x1 ? 0 : mask_p->x1 - pos_x;
lv_coord_t col_end = pos_x + letter_w <= mask_p->x2 ? letter_w : mask_p->x2 - pos_x + 1;
lv_coord_t row_start = pos_y >= mask_p->y1 ? 0 : mask_p->y1 - pos_y;
lv_coord_t row_end = pos_y + letter_h <= mask_p->y2 ? letter_h : mask_p->y2 - pos_y + 1;
/*Set a pointer on VDB to the first pixel of the letter*/
vdb_buf_tmp += ((pos_y - vdb_p->area.y1) * vdb_width)
+ pos_x - vdb_p->area.x1;
/*If the letter is partially out of mask the move there on VDB*/
vdb_buf_tmp += (row_start * vdb_width) + col_start;
/*Move on the map too*/
map_p += (row_start * width_byte_bpp) + ((col_start * bpp) >> 3);
lv_disp_t * disp = lv_disp_get_active();
uint8_t letter_px;
lv_opa_t px_opa;
for(row = row_start; row < row_end; row ++) {
col_byte_cnt = 0;
col_bit = (col_start * bpp) % 8;
mask = mask_init >> col_bit;
for(col = col_start; col < col_end; col ++) {
letter_px = (*map_p & mask) >> (8 - col_bit - bpp);
if(letter_px != 0) {
if(opa == LV_OPA_COVER) {
px_opa = bpp == 8 ? letter_px : bpp_opa_table[letter_px];
} else {
px_opa = bpp == 8 ?
(uint16_t)((uint16_t)letter_px * opa) >> 8 :
(uint16_t)((uint16_t)bpp_opa_table[letter_px] * opa) >> 8;
}
if(disp->driver.vdb_wr) {
disp->driver.vdb_wr((uint8_t *)vdb_p->buf, vdb_width,
(col + pos_x) - vdb_p->area.x1, (row + pos_y) - vdb_p->area.y1,
color, px_opa);
} else {
#if LV_COLOR_SCREEN_TRANSP == 0
*vdb_buf_tmp = lv_color_mix(color, *vdb_buf_tmp, px_opa);
#else
*vdb_buf_tmp = color_mix_2_alpha(*vdb_buf_tmp, (*vdb_buf_tmp).alpha, color, px_opa);
#endif
}
}
vdb_buf_tmp++;
if(col_bit < 8 - bpp) {
col_bit += bpp;
mask = mask >> bpp;
} else {
col_bit = 0;
col_byte_cnt ++;
mask = mask_init;
map_p ++;
}
}
map_p += (width_byte_bpp) - col_byte_cnt;
vdb_buf_tmp += vdb_width - (col_end - col_start); /*Next row in VDB*/
}
}
/**
* Draw a color map to the display (image)
* @param cords_p coordinates the color map
* @param mask_p the map will drawn only on this area (truncated to VDB area)
* @param map_p pointer to a lv_color_t array
* @param opa opacity of the map
* @param chroma_keyed true: enable transparency of LV_IMG_LV_COLOR_TRANSP color pixels
* @param alpha_byte true: extra alpha byte is inserted for every pixel
* @param recolor mix the pixels with this color
* @param recolor_opa the intense of recoloring
*/
void lv_vmap(const lv_area_t * cords_p, const lv_area_t * mask_p,
const uint8_t * map_p, lv_opa_t opa, bool chroma_key, bool alpha_byte,
lv_color_t recolor, lv_opa_t recolor_opa)
{
if(opa < LV_OPA_MIN) return;
if(opa > LV_OPA_MAX) opa = LV_OPA_COVER;
lv_area_t masked_a;
bool union_ok;
lv_vdb_t * vdb_p = lv_vdb_get();
if(!vdb_p) {
LV_LOG_WARN("Invalid VDB pointer");
return;
}
/*Get the union of map size and mask*/
/* The mask is already truncated to the vdb size
* in 'lv_refr_area_with_vdb' function */
union_ok = lv_area_intersect(&masked_a, cords_p, mask_p);
/*If there are common part of the three area then draw to the vdb*/
if(union_ok == false) return;
/*The pixel size in byte is different if an alpha byte is added too*/
uint8_t px_size_byte = alpha_byte ? LV_IMG_PX_SIZE_ALPHA_BYTE : sizeof(lv_color_t);
/*If the map starts OUT of the masked area then calc. the first pixel*/
lv_coord_t map_width = lv_area_get_width(cords_p);
if(cords_p->y1 < masked_a.y1) {
map_p += (uint32_t) map_width * ((masked_a.y1 - cords_p->y1)) * px_size_byte;
}
if(cords_p->x1 < masked_a.x1) {
map_p += (masked_a.x1 - cords_p->x1) * px_size_byte;
}
/*Stores coordinates relative to the current VDB*/
masked_a.x1 = masked_a.x1 - vdb_p->area.x1;
masked_a.y1 = masked_a.y1 - vdb_p->area.y1;
masked_a.x2 = masked_a.x2 - vdb_p->area.x1;
masked_a.y2 = masked_a.y2 - vdb_p->area.y1;
lv_coord_t vdb_width = lv_area_get_width(&vdb_p->area);
lv_color_t * vdb_buf_tmp = vdb_p->buf;
vdb_buf_tmp += (uint32_t) vdb_width * masked_a.y1; /*Move to the first row*/
vdb_buf_tmp += (uint32_t) masked_a.x1; /*Move to the first col*/
lv_coord_t row;
lv_coord_t map_useful_w = lv_area_get_width(&masked_a);
lv_disp_t * disp = lv_disp_get_active();
/*The simplest case just copy the pixels into the VDB*/
if(chroma_key == false && alpha_byte == false && opa == LV_OPA_COVER && recolor_opa == LV_OPA_TRANSP) {
/*Use the custom VDB write function is exists*/
if(disp->driver.vdb_wr) {
lv_coord_t col;
for(row = masked_a.y1; row <= masked_a.y2; row++) {
for(col = 0; col < map_useful_w; col++) {
lv_color_t px_color = *((lv_color_t *)&map_p[(uint32_t)col * px_size_byte]);
disp->driver.vdb_wr((uint8_t *)vdb_p->buf, vdb_width, col + masked_a.x1, row, px_color, opa);
}
map_p += map_width * px_size_byte; /*Next row on the map*/
}
}
/*Normal native VDB*/
else {
for(row = masked_a.y1; row <= masked_a.y2; row++) {
#if USE_LV_GPU
if(lv_disp_is_mem_blend_supported() == false) {
sw_mem_blend(vdb_buf_tmp, (lv_color_t *)map_p, map_useful_w, opa);
} else {
lv_disp_mem_blend(vdb_buf_tmp, (lv_color_t *)map_p, map_useful_w, opa);
}
#else
sw_mem_blend(vdb_buf_tmp, (lv_color_t *)map_p, map_useful_w, opa);
#endif
map_p += map_width * px_size_byte; /*Next row on the map*/
vdb_buf_tmp += vdb_width; /*Next row on the VDB*/
}
}
}
/*In the other cases every pixel need to be checked one-by-one*/
else {
lv_color_t chroma_key_color = LV_COLOR_TRANSP;
lv_coord_t col;
lv_color_t last_img_px = LV_COLOR_BLACK;
lv_color_t recolored_px = lv_color_mix(recolor, last_img_px, recolor_opa);
for(row = masked_a.y1; row <= masked_a.y2; row++) {
for(col = 0; col < map_useful_w; col++) {
lv_opa_t opa_result = opa;
uint8_t * px_color_p = (uint8_t *) &map_p[(uint32_t)col * px_size_byte];
lv_color_t px_color;
/*Calculate with the pixel level alpha*/
if(alpha_byte) {
#if LV_COLOR_DEPTH == 8 || LV_COLOR_DEPTH == 1
px_color.full = px_color_p[0];
#elif LV_COLOR_DEPTH == 16
/*Because of Alpha byte 16 bit color can start on odd address which can cause crash*/
px_color.full = px_color_p[0] + (px_color_p[1] << 8);
#elif LV_COLOR_DEPTH == 32
px_color = *((lv_color_t *)px_color_p);
#endif
lv_opa_t px_opa = *(px_color_p + LV_IMG_PX_SIZE_ALPHA_BYTE - 1);
if(px_opa == LV_OPA_TRANSP) continue;
else if(px_opa != LV_OPA_COVER) opa_result = (uint32_t)((uint32_t)px_opa * opa_result) >> 8;
} else {
px_color = *((lv_color_t *)px_color_p);
}
/*Handle chroma key*/
if(chroma_key && px_color.full == chroma_key_color.full) continue;
/*Re-color the pixel if required*/
if(recolor_opa != LV_OPA_TRANSP) {
if(last_img_px.full != px_color.full) { /*Minor acceleration: calculate only for new colors (save the last)*/
last_img_px = px_color;
recolored_px = lv_color_mix(recolor, last_img_px, recolor_opa);
}
/*Handle custom VDB write is present*/
if(disp->driver.vdb_wr) {
disp->driver.vdb_wr((uint8_t *)vdb_p->buf, vdb_width, col + masked_a.x1, row, recolored_px, opa_result);
}
/*Normal native VDB write*/
else {
if(opa_result == LV_OPA_COVER) vdb_buf_tmp[col].full = recolored_px.full;
else vdb_buf_tmp[col] = lv_color_mix(recolored_px, vdb_buf_tmp[col], opa_result);
}
} else {
/*Handle custom VDB write is present*/
if(disp->driver.vdb_wr) {
disp->driver.vdb_wr((uint8_t *)vdb_p->buf, vdb_width, col + masked_a.x1, row, px_color, opa_result);
}
/*Normal native VDB write*/
else {
if(opa_result == LV_OPA_COVER) vdb_buf_tmp[col] = px_color;
else {
#if LV_COLOR_SCREEN_TRANSP == 0
vdb_buf_tmp[col] = lv_color_mix(px_color, vdb_buf_tmp[col], opa_result);
#else
vdb_buf_tmp[col] = color_mix_2_alpha(vdb_buf_tmp[col], vdb_buf_tmp[col].alpha, px_color, opa_result);
#endif
}
}
}
}
map_p += map_width * px_size_byte; /*Next row on the map*/
vdb_buf_tmp += vdb_width; /*Next row on the VDB*/
}
}
}
/**********************
* STATIC FUNCTIONS
**********************/
/**
* Blend pixels to destination memory using opacity
* @param dest a memory address. Copy 'src' here.
* @param src pointer to pixel map. Copy it to 'dest'.
* @param length number of pixels in 'src'
* @param opa opacity (0, LV_OPA_TRANSP: transparent ... 255, LV_OPA_COVER, fully cover)
*/
static void sw_mem_blend(lv_color_t * dest, const lv_color_t * src, uint32_t length, lv_opa_t opa)
{
if(opa == LV_OPA_COVER) {
memcpy(dest, src, length * sizeof(lv_color_t));
} else {
uint32_t col;
for(col = 0; col < length; col++) {
dest[col] = lv_color_mix(src[col], dest[col], opa);
}
}
}
/**
*
* @param mem_area coordinates of 'mem' memory area
* @param mem a memory address. Considered to a rectangular window according to 'mem_area'
* @param fill_area coordinates of an area to fill. Relative to 'mem_area'.
* @param color fill color
* @param opa opacity (0, LV_OPA_TRANSP: transparent ... 255, LV_OPA_COVER, fully cover)
*/
static void sw_color_fill(lv_area_t * mem_area, lv_color_t * mem, const lv_area_t * fill_area, lv_color_t color, lv_opa_t opa)
{
/*Set all row in vdb to the given color*/
lv_coord_t row;
lv_coord_t col;
lv_coord_t mem_width = lv_area_get_width(mem_area);
lv_disp_t * disp = lv_disp_get_active();
if(disp->driver.vdb_wr) {
for(col = fill_area->x1; col <= fill_area->x2; col++) {
for(row = fill_area->y1; row <= fill_area->y2; row++) {
disp->driver.vdb_wr((uint8_t *)mem, mem_width, col, row, color, opa);
}
}
} else {
mem += fill_area->y1 * mem_width; /*Go to the first row*/
/*Run simpler function without opacity*/
if(opa == LV_OPA_COVER) {
/*Fill the first row with 'color'*/
for(col = fill_area->x1; col <= fill_area->x2; col++) {
mem[col] = color;
}
/*Copy the first row to all other rows*/
lv_color_t * mem_first = &mem[fill_area->x1];
lv_coord_t copy_size = (fill_area->x2 - fill_area->x1 + 1) * sizeof(lv_color_t);
mem += mem_width;
for(row = fill_area->y1 + 1; row <= fill_area->y2; row++) {
memcpy(&mem[fill_area->x1], mem_first, copy_size);
mem += mem_width;
}
}
/*Calculate with alpha too*/
else {
#if LV_COLOR_SCREEN_TRANSP == 0
lv_color_t bg_tmp = LV_COLOR_BLACK;
lv_color_t opa_tmp = lv_color_mix(color, bg_tmp, opa);
#endif
for(row = fill_area->y1; row <= fill_area->y2; row++) {
for(col = fill_area->x1; col <= fill_area->x2; col++) {
#if LV_COLOR_SCREEN_TRANSP == 0
/*If the bg color changed recalculate the result color*/
if(mem[col].full != bg_tmp.full) {
bg_tmp = mem[col];
opa_tmp = lv_color_mix(color, bg_tmp, opa);
}
mem[col] = opa_tmp;
#else
mem[col] = color_mix_2_alpha(mem[col], mem[col].alpha, color, opa);
#endif
}
mem += mem_width;
}
}
}
}
#if LV_COLOR_SCREEN_TRANSP
/**
* Mix two colors. Both color can have alpha value. It requires ARGB888 colors.
* @param bg_color background color
* @param bg_opa alpha of the background color
* @param fg_color foreground color
* @param fg_opa alpha of the foreground color
* @return the mixed color. the alpha channel (color.alpha) contains the result alpha
*/
static inline lv_color_t color_mix_2_alpha(lv_color_t bg_color, lv_opa_t bg_opa, lv_color_t fg_color, lv_opa_t fg_opa)
{
/* Pick the foreground if it's fully opaque or the Background is fully transparent*/
if(fg_opa == LV_OPA_COVER && bg_opa <= LV_OPA_MIN) {
fg_color.alpha = fg_opa;
return fg_color;
}
/*Transparent foreground: use the Background*/
else if(fg_opa <= LV_OPA_MIN) {
return bg_color;
}
/*Opaque background: use simple mix*/
else if(bg_opa >= LV_OPA_MAX) {
return lv_color_mix(fg_color, bg_color, fg_opa);
}
/*Both colors have alpha. Expensive calculation need to be applied*/
else {
/*Save the parameters and the result. If they will be asked again don't compute again*/
static lv_opa_t fg_opa_save = 0;
static lv_opa_t bg_opa_save = 0;
static lv_color_t c = {{0}};
if(fg_opa != fg_opa_save || bg_opa != bg_opa_save) {
fg_opa_save = fg_opa;
bg_opa_save = bg_opa;
/*Info: https://en.wikipedia.org/wiki/Alpha_compositing#Analytical_derivation_of_the_over_operator*/
lv_opa_t alpha_res = 255 - ((uint16_t)((uint16_t)(255 - fg_opa) * (255 - bg_opa)) >> 8);
if(alpha_res == 0) {
while(1);
}
lv_opa_t ratio = (uint16_t)((uint16_t) fg_opa * 255) / alpha_res;
c = lv_color_mix(fg_color, bg_color, ratio);
c.alpha = alpha_res;
}
return c;
}
}
#endif /*LV_COLOR_SCREEN_TRANSP*/
#endif
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