test triangle rendered?

2026-09-13 22:30:19 +03:00
parent 4e1fa1ed1c
commit 578c4a6d4f
6 changed files with 193 additions and 3 deletions
@@ -0,0 +1,86 @@
+/*
+    Fixed point implementation of 2 dimensional pnttors.
+*/
+
+#ifndef COM_PNT_H
+#define COM_PNT_H
+
+#include "def.h"
+#include "fix.h"
+#include "vec.h"
+#include <stdint.h>
+
+typedef union {
+  com_def_alignedas(16) com_def_vector(com_fix_t, a, 2);
+  com_def_alignedas(16) struct {
+    com_fix_t x;
+    com_fix_t y;
+  } s;
+} com_pnt_t;
+
+static inline com_pnt_t com_pnt_from(com_fix_t x, com_fix_t y) {
+  return (com_pnt_t){.s = {.x = x, .y = y}};
+}
+
+static inline com_pnt_t com_pnt_from_vec(com_vec_t a) {
+  return (com_pnt_t){.s = {.x = a.a[0], .y = a.a[1]}};
+}
+
+static inline com_pnt_t com_pnt_identity(void) {
+  return (com_pnt_t){.s = {
+                         .x = COM_FIX_FRACUNIT,
+                         .y = COM_FIX_FRACUNIT,
+                     }};
+}
+
+static inline com_pnt_t com_pnt_add(com_pnt_t a, com_pnt_t b) {
+  return (com_pnt_t){
+      .s = {.x = com_fix_add(a.s.x, b.s.x), .y = com_fix_add(a.s.y, b.s.y)}};
+}
+
+static inline com_pnt_t com_pnt_sub(com_pnt_t a, com_pnt_t b) {
+  return (com_pnt_t){
+      .s = {.x = com_fix_sub(a.s.x, b.s.x), .y = com_fix_sub(a.s.y, b.s.y)}};
+}
+
+static inline com_pnt_t com_pnt_mul(com_pnt_t a, com_pnt_t b) {
+  return (com_pnt_t){
+      .s = {.x = com_fix_mul(a.s.x, b.s.x), .y = com_fix_mul(a.s.y, b.s.y)}};
+}
+
+/* Note: this does not clamp for over/underflow cases */
+static inline com_pnt_t com_pnt_div(com_pnt_t a, com_pnt_t b) {
+  return (com_pnt_t){
+      .s = {.x = com_fix_div(a.s.x, b.s.x), .y = com_fix_div(a.s.y, b.s.y)}};
+}
+
+/* Scale pnttor by a fixed point number */
+static inline com_pnt_t com_pnt_scl(com_pnt_t a, com_fix_t b) {
+  return (com_pnt_t){
+      .s = {.x = com_fix_mul(a.s.x, b), .y = com_fix_mul(a.s.y, b)}};
+}
+
+static inline com_fix_t com_pnt_min(com_pnt_t a) {
+  return com_fix_min(a.a[0], a.a[1]);
+}
+
+static inline com_fix_t com_pnt_max(com_pnt_t a) {
+  return com_fix_max(a.a[0], a.a[1]);
+}
+
+/* TODO: Safeguard by com_fix_mul()? */
+/* Tests whether a point is lying right to a line produced by l0 and l1.
+   This assumes that l0 and l1 are in clockwise order.
+   Result is positive or zero if it holds true, otherwise it's negative. */
+static inline com_fix_t com_pnt_edge_orient(com_pnt_t l0, com_pnt_t l1,
+                                            com_pnt_t p) {
+  return (l0.s.x - l1.s.x) * (p.s.y - l1.s.y) -
+         (l0.s.y - l1.s.y) * (p.s.x - l1.s.x);
+}
+
+static inline void com_pnt_print(com_pnt_t a) {
+  com_fix_print(a.a[0]);
+  com_fix_print(a.a[1]);
+}
+
+#endif