feat: TrueType (TTF) font rendering, many new desktop applications and DOOM support, among other improvements

2026-02-20 22:46:41 +01:00
parent a0db5899ef
commit 596be25eaf
124 changed files with 9021 additions and 355 deletions
@@ -0,0 +1,95 @@
+/*
+    * stb_math.h
+    * Math functions for stb_truetype in freestanding environment
+    * Copyright (c) 2026 Daniel Hammer
+*/
+
+#ifndef STB_MATH_H
+#define STB_MATH_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+static inline double stb_floor(double x) {
+    double i = (double)(long long)x;
+    return (x < i) ? i - 1.0 : i;
+}
+
+static inline double stb_ceil(double x) {
+    double f = stb_floor(x);
+    return (x > f) ? f + 1.0 : f;
+}
+
+static inline double stb_fabs(double x) {
+    return x < 0.0 ? -x : x;
+}
+
+static inline double stb_fmod(double x, double y) {
+    if (y == 0.0) return 0.0;
+    return x - (double)((long long)(x / y)) * y;
+}
+
+static inline double stb_sqrt(double x) {
+    if (x <= 0.0) return 0.0;
+    double guess = x;
+    for (int i = 0; i < 30; i++)
+        guess = (guess + x / guess) * 0.5;
+    return guess;
+}
+
+static inline double stb_pow(double base, double exp) {
+    if (exp == 0.0) return 1.0;
+    if (exp == 1.0) return base;
+    if (base == 0.0) return 0.0;
+    // Integer exponent fast path
+    if (exp == (double)(long long)exp) {
+        long long e = (long long)exp;
+        int neg = 0;
+        if (e < 0) { neg = 1; e = -e; }
+        double r = 1.0;
+        double b = base;
+        while (e > 0) {
+            if (e & 1) r *= b;
+            b *= b;
+            e >>= 1;
+        }
+        return neg ? 1.0 / r : r;
+    }
+    return 0.0;
+}
+
+static inline double stb_cos(double x) {
+    // Reduce to [0, 2*pi]
+    const double PI = 3.14159265358979323846;
+    const double TWO_PI = 6.28318530717958647692;
+    x = stb_fmod(stb_fabs(x), TWO_PI);
+    // Taylor series: cos(x) = 1 - x^2/2! + x^4/4! - x^6/6! + ...
+    double x2 = x * x;
+    double term = 1.0;
+    double result = 1.0;
+    for (int i = 1; i <= 10; i++) {
+        term *= -x2 / (double)((2 * i - 1) * (2 * i));
+        result += term;
+    }
+    return result;
+}
+
+static inline double stb_acos(double x) {
+    // Clamp input
+    if (x <= -1.0) return 3.14159265358979323846;
+    if (x >= 1.0) return 0.0;
+    // Polynomial approximation (Abramowitz & Stegun style)
+    double ax = stb_fabs(x);
+    double result = (-0.0187293 * ax + 0.0742610) * ax - 0.2121144;
+    result = (result * ax + 1.5707288) * stb_sqrt(1.0 - ax);
+    if (x < 0.0)
+        return 3.14159265358979323846 - result;
+    return result;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // STB_MATH_H