blend: conditionally blend in alpha

This commit is contained in:
nick black 2020-01-12 07:42:54 -05:00 committed by Nick Black
parent f280db744d
commit 2ebc3e2bfe
3 changed files with 18 additions and 7 deletions

View File

@ -1117,13 +1117,19 @@ channels_blend(unsigned c1, unsigned c2, unsigned blends){
unsigned rsum, gsum, bsum;
if(blends == 0){
// don't just return c2, or you set wide status and all kinds of crap
channel_rgb(c2, &rsum, &gsum, &bsum);
channel_set_rgb(&c1, rsum, gsum, bsum);
if(channel_default_p(c2)){
channel_set_default(&c1);
}else{
channel_rgb(c2, &rsum, &gsum, &bsum);
channel_set_rgb(&c1, rsum, gsum, bsum);
}
channel_set_alpha(&c1, channel_alpha(c2));
}else if(!channel_default_p(c2) && !channel_default_p(c1)){
rsum = (channel_r(c1) * blends + channel_r(c2)) / (blends + 1);
gsum = (channel_g(c1) * blends + channel_g(c2)) / (blends + 1);
bsum = (channel_b(c1) * blends + channel_b(c2)) / (blends + 1);
channel_set_rgb(&c1, rsum, gsum, bsum);
channel_set_alpha(&c1, channel_alpha(c2));
}
return c1;
}

View File

@ -17,6 +17,12 @@ mathplane(struct notcurses* nc){
const int HEIGHT = 9;
const int WIDTH = dimx;
struct ncplane* n = ncplane_new(nc, HEIGHT, WIDTH, dimy - HEIGHT - 1, dimx - WIDTH, NULL);
cell b = CELL_TRIVIAL_INITIALIZER;
cell_set_fg_rgb(&b, 0xff, 0xff, 0xff);
cell_set_fg_alpha(&b, CELL_ALPHA_BLEND);
cell_set_bg_alpha(&b, CELL_ALPHA_TRANSPARENT);
ncplane_set_base(n, &b);
cell_release(n, &b);
ncplane_set_fg_rgb(n, 0xff, 0xff, 0xff);
if(n){
ncplane_printf_aligned(n, 0, NCALIGN_RIGHT, "∮E⋅da=Q,n→∞,∑f(i)=∏g(i)⎧⎡⎛┌─────┐⎞⎤⎫");
@ -67,6 +73,7 @@ surrounding_cells(struct ncplane* n, cell* cells, int y, int x){
static int
lightup_surrounding_cells(struct ncplane* n, const cell* cells, int y, int x){
cell c = CELL_TRIVIAL_INITIALIZER;
/*
cell_duplicate(n, &c, &cells[0]);
lighten(n, &c, 2, y - 1, x - 1);
cell_duplicate(n, &c, &cells[1]);
@ -91,6 +98,7 @@ lightup_surrounding_cells(struct ncplane* n, const cell* cells, int y, int x){
lighten(n, &c, 2, y, x - 2);
cell_duplicate(n, &c, &cells[11]);
lighten(n, &c, 2, y, x + 2);
*/
cell_duplicate(n, &c, &cells[12]);
lighten(n, &c, 0, y, x);
cell_release(n, &c);

View File

@ -143,16 +143,13 @@ TEST_CASE("ChannelBlendDefaultRight") {
uint32_t c1 = 0;
uint32_t c2 = 0;
channel_set_rgb(&c1, 0x80, 0x40, 0x20);
CHECK(!channel_default_p(c1));
CHECK(channel_default_p(c2));
uint32_t c = channels_blend(c1, c2, 0);
CHECK(channel_default_p(c));
unsigned r, g, b;
channel_rgb(c, &r, &g, &b);
CHECK(0 == r);
CHECK(0 == g);
CHECK(0 == b);
c = channels_blend(c1, c2, 1);
CHECK(!channel_default_p(c));
unsigned r, g, b;
channel_rgb(c, &r, &g, &b);
CHECK(0x80 == r);
CHECK(0x40 == g);