Eliminate pen style and history stream parameter smuggling

- Introduce struct text_pen bundling (fg, bg, sl) across screen and core
- Reduce text_append from 9 to 7 parameters
- Reduce text_commit from 8 to 6 parameters
- Reduce hist_runs_add_pen from 5 to 3 parameters
- Reduce sc_text_ascii and sc_ascii_fast from 6 to 4 parameters
- Remove unused fg, bg parameters from mark_row_blank
- Introduce struct hist_stream_state in src/hist.c, reducing stream_lines from 9 to 5 params and lf_rows from 10 to 6 params
- Introduce struct hist_view_pos in src/hist_view.h, reducing term_hist_view_row_pos from 9 to 7 params

1 files changed, 41 insertions, 0 deletions

diff --git a/src/pen.h b/src/pen.h
index 8349566..f84d6e3 100644
--- a/src/pen.h
+++ b/src/pen.h
@@ -5,6 +5,7 @@
 #include "term.h"
 #include <stdbool.h>
 #include <stdint.h>
+#include <string.h>
 
 struct term_pen {
     uint32_t fg;
@@ -28,6 +29,46 @@ struct pen_attr {
     uint16_t link;
 };
 
+/* A pen as three words: fg, bg, and flags | link << 16 (the layout of
+ * pen_attr.flags and .link). The hot path reads and writes whole words, so
+ * a store is never read back through a wider load. */
+struct text_pen {
+    uint32_t fg;
+    uint32_t bg;
+    uint32_t sl;
+};
+
+static inline struct text_pen text_pen(uint32_t fg, uint32_t bg, uint32_t sl)
+{
+    return (struct text_pen){ fg, bg, sl };
+}
+
+static inline uint32_t pen_sl(const struct pen_attr *p)
+{
+    uint32_t sl;
+    memcpy(&sl, &p->flags, 4);
+    return sl;
+}
+
+static inline struct text_pen text_pen_from_attr(const struct pen_attr *p)
+{
+    return (struct text_pen){ p->fg, p->bg, pen_sl(p) };
+}
+
+static inline void pen_set(struct pen_attr *p, uint32_t fg, uint32_t bg, uint32_t sl)
+{
+    p->fg = fg;
+    p->bg = bg;
+    memcpy(&p->flags, &sl, 4);
+}
+
+static inline void pen_set_text(struct pen_attr *p, struct text_pen pen)
+{
+    p->fg = pen.fg;
+    p->bg = pen.bg;
+    memcpy(&p->flags, &pen.sl, 4);
+}
+
 static inline struct pen_attr pen_attr_default(void)
 {
     return (struct pen_attr){ .fg = TERM_COLOR_FG, .bg = TERM_COLOR_BG };