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lv_canvas: handle alpha in rotate

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This commit is contained in:
Gabor Kiss-Vamosi 2019-03-27 00:05:15 +01:00
parent 41754236f8
commit 5be450a3aa
2 changed files with 78 additions and 11 deletions
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74
src/lv_objx/lv_canvas.c
View File

@ -80,8 +80,6 @@ lv_obj_t * lv_canvas_create(lv_obj_t * par, const lv_obj_t * copy)
}
/*Copy an existing canvas*/
else {
//lv_canvas_ext_t * copy_ext = lv_obj_get_ext_attr(copy);
/*Refresh the style with new signal function*/
lv_obj_refresh_style(new_canvas);
}
@ -133,7 +131,7 @@ void lv_canvas_set_px(lv_obj_t * canvas, lv_coord_t x, lv_coord_t y, lv_color_t
{
lv_canvas_ext_t * ext = lv_obj_get_ext_attr(canvas);
lv_img_buf_set_px(&ext->dsc, x, y, c);
lv_img_buf_set_px_color(&ext->dsc, x, y, c);
lv_obj_invalidate(canvas);
}
@ -167,8 +165,9 @@ void lv_canvas_set_style(lv_obj_t * canvas, lv_canvas_style_t type, lv_style_t *
lv_color_t lv_canvas_get_px(lv_obj_t * canvas, lv_coord_t x, lv_coord_t y)
{
lv_canvas_ext_t * ext = lv_obj_get_ext_attr(canvas);
lv_style_t * style = lv_canvas_get_style(canvas, LV_CANVAS_STYLE_MAIN);
return lv_img_buf_get_px(&ext->dsc, x, y);
return lv_img_buf_get_px_color(&ext->dsc, x, y, style);
}
/**
@ -180,7 +179,7 @@ lv_img_dsc_t * lv_canvas_get_img(lv_obj_t * canvas)
{
lv_canvas_ext_t * ext = lv_obj_get_ext_attr(canvas);
return &ext->img;
return &ext->dsc;
}
/**
@ -311,7 +310,7 @@ void lv_canvas_mult_buf(lv_obj_t * canvas, void * to_copy, lv_coord_t w, lv_coor
void lv_canvas_rotate(lv_obj_t * canvas, lv_img_dsc_t * img, int16_t angle,lv_coord_t offset_x, lv_coord_t offset_y, int32_t pivot_x, int32_t pivot_y)
{
lv_canvas_ext_t * ext_dst = lv_obj_get_ext_attr(canvas);
lv_style_t * style = lv_canvas_get_style(canvas, LV_CANVAS_STYLE_MAIN);
int32_t sinma = lv_trigo_sin(-angle);
int32_t cosma = lv_trigo_sin(-angle + 90); /* cos */
@ -391,16 +390,69 @@ void lv_canvas_rotate(lv_obj_t * canvas, lv_img_dsc_t * img, int16_t angle,lv_co
else if(yn < 0) continue;
/*Get the mixture of the original source and the neightboor pixels in both directions*/
lv_color_t c_dest_int = lv_img_buf_get_px(img, xs_int, ys_int);
lv_color_t c_dest_xn = lv_img_buf_get_px(img, xn, ys_int);
lv_color_t c_dest_yn = lv_img_buf_get_px(img, xs_int, yn);
lv_color_t c_dest_int = lv_img_buf_get_px_color(img, xs_int, ys_int, style);
if(lv_img_color_format_is_chroma_keyed(img->header.cf)) {
lv_color_t ct = LV_COLOR_TRANSP;
if(c_dest_int.full == ct.full) continue;
}
lv_color_t c_dest_xn = lv_img_buf_get_px_color(img, xn, ys_int, style);
lv_color_t c_dest_yn = lv_img_buf_get_px_color(img, xs_int, yn, style);
lv_color_t x_dest = lv_color_mix(c_dest_int, c_dest_xn, xr);
lv_color_t y_dest = lv_color_mix(c_dest_int, c_dest_yn, yr);
lv_color_t color_res = lv_color_mix(x_dest, y_dest, LV_OPA_50);
if (x + offset_x >= 0 && x + offset_x < dest_width && y + offset_y >= 0 && y + offset_y < dest_height)
{
/*The result color as the average of the x/y mixed colors*/
lv_img_buf_set_px(&ext_dst->dsc, x + offset_x, y + offset_y, lv_color_mix(x_dest, y_dest, LV_OPA_50));
/*If the image has no alpha channel just simple set the result color on the canvas*/
if(lv_img_color_format_has_alpha(img->header.cf) == false) {
lv_img_buf_set_px_color(&ext_dst->dsc, x + offset_x, y + offset_y, color_res);
} else {
/*Get result pixel opacity*/
lv_opa_t opa_int = lv_img_buf_get_px_alpha(img, xs_int, ys_int);
lv_opa_t opa_xn = lv_img_buf_get_px_alpha(img, xn, ys_int);
lv_opa_t opa_yn = lv_img_buf_get_px_alpha(img, xs_int, yn);
lv_opa_t opa_x = (opa_int * xr + (opa_xn * (255 - xr))) >> 8;
lv_opa_t opa_y = (opa_int * yr + (opa_yn * (255 - yr))) >> 8;
lv_opa_t opa_res = (opa_x + opa_y) / 2;
if(opa_res <= LV_OPA_MIN) continue;
lv_color_t bg_color = lv_img_buf_get_px_color(&ext_dst->dsc, x + offset_x, y + offset_y, style);
/*If the canvas has no alpha but the image has mix the image's color with canvas*/
if(lv_img_color_format_has_alpha(ext_dst->dsc.header.cf) == false) {
if(opa_res < LV_OPA_MAX) color_res = lv_color_mix(color_res, bg_color, opa_res);
lv_img_buf_set_px_color(&ext_dst->dsc, x + offset_x, y + offset_y, color_res);
}
/*Both the image and canvas has alpha channel. Some extra calculation is required*/
else {
lv_opa_t bg_opa = lv_img_buf_get_px_alpha(&ext_dst->dsc, x + offset_x, y + offset_y);
/* Pick the foreground if it's fully opaque or the Background is fully transparent*/
if(opa_res >= LV_OPA_MAX || bg_opa <= LV_OPA_MIN) {
lv_img_buf_set_px_color(&ext_dst->dsc, x + offset_x, y + offset_y, color_res);
lv_img_buf_set_px_alpha(&ext_dst->dsc, x + offset_x, y + offset_y, opa_res);
}
/*Opaque background: use simple mix*/
else if(bg_opa >= LV_OPA_MAX) {
lv_img_buf_set_px_color(&ext_dst->dsc, x + offset_x, y + offset_y, lv_color_mix(color_res, bg_color, opa_res));
}
/*Both colors have alpha. Expensive calculation need to be applied*/
else {
/*Info: https://en.wikipedia.org/wiki/Alpha_compositing#Analytical_derivation_of_the_over_operator*/
lv_opa_t opa_res_2 = 255 - ((uint16_t)((uint16_t)(255 - opa_res) * (255 - bg_opa)) >> 8);
if(opa_res_2 == 0) {
opa_res_2 = 1; /*never happens, just to be sure*/
}
lv_opa_t ratio = (uint16_t)((uint16_t) opa_res * 255) / opa_res_2;
lv_img_buf_set_px_color(&ext_dst->dsc, x + offset_x, y + offset_y, lv_color_mix(color_res, bg_color, ratio));
lv_img_buf_set_px_alpha(&ext_dst->dsc, x + offset_x, y + offset_y, opa_res_2);
}
}
}
}
}
}

15
src/lv_objx/lv_canvas.h
View File

@ -230,6 +230,21 @@ void lv_canvas_flood_fill(lv_obj_t * canvas, lv_coord_t x, lv_coord_t y, lv_colo
/**********************
* MACROS
**********************/
#define LV_CANVAS_BUF_SIZE_TRUE_COLOR(w,h) ((LV_COLOR_SIZE / 8) * w * h)
#define LV_CANVAS_BUF_SIZE_TRUE_COLOR_CHROMA_KEYED(w,h) ((LV_COLOR_SIZE / 8) * w * h)
#define LV_CANVAS_BUF_SIZE_TRUE_COLOR_ALPHA(w,h) (LV_IMG_PX_SIZE_ALPHA_BYTE * w * h)
#define LV_CANVAS_BUF_SIZE_ALPHA_1BIT(w,h) ((((w / 8) + 1) * h)) /*(w / 8) + 1): to be sure no fractional row; LV_COLOR_SIZE / 8) * 2: palette*/
#define LV_CANVAS_BUF_SIZE_INDEXED_1BIT(w,h) (LV_CANVAS_BUF_SIZE_ALPHA_1BIT(w,h) + 4 * 2) /*4 * 2: palette*/
#define LV_CANVAS_BUF_SIZE_ALPHA_2BIT(w,h) ((((w / 4) + 1) * h)) /*(w / 8) + 1): to be sure no fractional row; LV_COLOR_SIZE / 8) * 2: palette*/
#define LV_CANVAS_BUF_SIZE_INDEXED_2BIT(w,h) (LV_CANVAS_BUF_SIZE_ALPHA_2BIT(w,h) + 4 * 4) /*4 * 4: palette*/
#define LV_CANVAS_BUF_SIZE_ALPHA_4BIT(w,h) ((((w / 2) + 1) * h)) /*(w / 8) + 1): to be sure no fractional row; LV_COLOR_SIZE / 8) * 2: palette*/
#define LV_CANVAS_BUF_SIZE_INDEXED_4BIT(w,h) (LV_CANVAS_BUF_SIZE_ALPHA_4BIT(w,h) + 4 * 16) /*4 * 16: palette*/
#define LV_CANVAS_BUF_SIZE_ALPHA_8BIT(w,h) ((w * h))
#define LV_CANVAS_BUF_SIZE_INDEXED_8BIT(w,h) (LV_CANVAS_BUF_SIZE_ALPHA_8BIT(w,h) + 4 * 256) /*4 * 256: palette*/
#endif /*LV_USE_CANVAS*/