half-assed 3D graphics attempt underway

[regis] / fixed.h

diff --git a/fixed.h b/fixed.h
new file mode 100644 (file)
index 0000000..dbc8bbe
--- /dev/null
+++ b/fixed.h
@@ -0,0 +1,18 @@
+#ifndef FIXED_H_
+#define FIXED_H_
+
+#include <stdint.h>
+
+#define ftox16(x)              (int32_t)((x) * 65536.0f)
+#define itox16(x)              (int32_t)((x) << 16)
+
+#define x16tof(x)              (float)((x) / 65536.0f)
+#define x16toi(x)              ((x) >> 16)
+
+#define x16mul(a, b)   (int32_t)(((int32_t)(a) >> 8) * ((int32_t)(b) >> 8))
+/*int32_t x16div(register int32_t num, register int32_t denom);*/
+#define x16div(a, b)   (int32_t)(((int64_t)(a) << 16) / (b))
+
+#define x16sq(x)               x16mul(x, x)
+
+#endif /* FIXED_H_ */