From e37540c76e009a598b6444bb78435eba48e33b75 Mon Sep 17 00:00:00 2001
From: nick black <dankamongmen@gmail.com>
Date: Sun, 13 Dec 2020 07:22:43 -0500
Subject: [PATCH] ncprogbar: implement core draw loop #1202

---
 include/notcurses/notcurses.h |  3 ++-
 src/lib/fill.c                |  3 +--
 src/lib/internal.h            | 11 +++++++++++
 src/lib/progbar.c             | 25 ++++++++++++++++++++-----
 src/poc/progbar.c             |  2 +-
 5 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/include/notcurses/notcurses.h b/include/notcurses/notcurses.h
index 1ca6af080..5cf42be0c 100644
--- a/include/notcurses/notcurses.h
+++ b/include/notcurses/notcurses.h
@@ -3039,7 +3039,8 @@ API int ncmenu_destroy(struct ncmenu* n);
 
 typedef struct ncprogbar_options {
   // channels for the maximum and minimum points. linear interpolation will be
-  // applied across the domain between these two.
+  // applied across the domain between these two. for both channels, both min
+  // and max must either be RGB, or both default, and alphas must match.
   uint64_t maxchannels;
   uint64_t minchannels;
   // provide NULL for default (geometric) glyphs. otherwise, provide one or
diff --git a/src/lib/fill.c b/src/lib/fill.c
index afe899db9..554ae02f4 100644
--- a/src/lib/fill.c
+++ b/src/lib/fill.c
@@ -115,8 +115,7 @@ check_gradient_channel_args(uint32_t ul, uint32_t ur, uint32_t bl, uint32_t br){
 // - all foregrounds must have the same alpha
 // - all backgrounds must have the same alpha
 // - palette-indexed color must not be used
-static bool
-check_gradient_args(uint64_t ul, uint64_t ur, uint64_t bl, uint64_t br){
+bool check_gradient_args(uint64_t ul, uint64_t ur, uint64_t bl, uint64_t br){
   if(check_gradient_channel_args(channels_fchannel(ul), channels_fchannel(ur),
                                  channels_fchannel(bl), channels_fchannel(br))){
     return true;
diff --git a/src/lib/internal.h b/src/lib/internal.h
index 29c3c9394..c986eae60 100644
--- a/src/lib/internal.h
+++ b/src/lib/internal.h
@@ -1074,6 +1074,17 @@ int ncinputlayer_init(ncinputlayer* nilayer, FILE* infp);
 // FIXME absorb into ncinputlayer_init()
 int cbreak_mode(int ttyfd, const struct termios* tpreserved);
 
+// Given the four channels arguments, verify that:
+//
+// - if any is default foreground, all are default foreground
+// - if any is default background, all are default background
+// - all foregrounds must have the same alpha
+// - all backgrounds must have the same alpha
+// - palette-indexed color must not be used
+//
+// If you only want to check n < 4 channels, just duplicate one.
+bool check_gradient_args(uint64_t ul, uint64_t ur, uint64_t bl, uint64_t br);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/lib/progbar.c b/src/lib/progbar.c
index 3cd929908..1c89c3eed 100644
--- a/src/lib/progbar.c
+++ b/src/lib/progbar.c
@@ -9,6 +9,10 @@ ncprogbar* ncprogbar_create(ncplane* n, const ncprogbar_options* opts){
     default_opts.maxchannels = CHANNELS_RGB_INITIALIZER(0xe0, 0xee, 0xe0, 0, 0, 0);
     opts = &default_opts;
   }
+  if(check_gradient_args(opts->minchannels, opts->maxchannels, opts->minchannels, opts->maxchannels)){
+    logerror(ncplane_notcurses(n), "Illegal progbar colors\n");
+    return NULL;
+  }
   if(opts->flags > (NCPROGBAR_OPTION_FORCE_VERTICAL << 1u)){
     logwarn(ncplane_notcurses(n), "Invalid flags %016lx\n", opts->flags);
   }
@@ -55,13 +59,24 @@ progbar_redraw(ncprogbar* n){
   }else{ // PROGRESS_HORIZ
     direction = n->retrograde ? DIR_LEFT : DIR_RIGHT;
   }
-  int range;
-  if(direction == DIR_UP || direction == DIR_DOWN){
-    range = dimy;
-  }else{
+  const bool horizontal = (direction == DIR_LEFT || direction == DIR_RIGHT);
+  int delt, range;
+  if(horizontal){
     range = dimx;
+    delt = n->retrograde ? 1 : -1;
+  }else{
+    range = dimy;
+    delt = n->retrograde ? -1 : 1;
+  }
+  double progress = n->progress * range;
+  if(n->retrograde){
+    progress = range - progress;
+  }
+  while(progress > 0 && progress < range){
+    // FIXME lerp min->max
+    ncplane_putchar_yx(ncprogbar_plane(n), 0, progress, 'X');
+    progress += delt;
   }
-  // FIXME
   return 0;
 }
 
diff --git a/src/poc/progbar.c b/src/poc/progbar.c
index 84ac43cfe..5282a3491 100644
--- a/src/poc/progbar.c
+++ b/src/poc/progbar.c
@@ -16,7 +16,7 @@ pbar_fill(struct notcurses* nc, struct ncprogbar* pbar){
   const uint64_t deadline = startns + delay;
   do{
     uint64_t curns = ts_to_ns(&cur);
-    if(ncprogbar_set_progress(pbar, (curns - startns) / delay)){
+    if(ncprogbar_set_progress(pbar, (curns - startns) / (double)delay)){
       return -1;
     }
     notcurses_render(nc);