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Moved fixed point multiplication and rounding into an asm module.

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git-svn-id: svn://svn.cc65.org/cc65/trunk@4447 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
uz
2009-11-05 20:16:43 +00:00
parent de6050f21d
commit 787f069738
6 changed files with 75 additions and 17 deletions
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21
libsrc/tgi/tgi_arc.c
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@@ -34,6 +34,7 @@
#include <tgi.h>
#include <tgi/tgi-kernel.h>
#include <cc65.h>
@@ -44,18 +45,6 @@
static int RoundMul (int rhs, int lhs)
{
long res = cc65_imul16x16r32 (rhs, lhs);
if ((unsigned char)res & 0x80) {
return (int)(res >> 8) + 1;
} else {
return (int)(res >> 8);
}
}
void __fastcall__ tgi_arc (int x, int y, unsigned char rx, unsigned char ry,
unsigned sa, unsigned ea)
/* Draw an ellipse arc with center at x/y and radii rx/ry using the current
@@ -81,16 +70,16 @@ void __fastcall__ tgi_arc (int x, int y, unsigned char rx, unsigned char ry,
}
/* Calculate the start coords */
x1 = x + RoundMul (rx, cc65_cos (sa));
y1 = y + RoundMul (ry, cc65_sin (sa));
x1 = x + tgi_imulround (rx, cc65_cos (sa));
y1 = y + tgi_imulround (ry, cc65_sin (sa));
do {
sa += inc;
if (sa >= ea) {
sa = ea;
done = 1;
}
x2 = x + RoundMul (rx, cc65_cos (sa));
y2 = y - RoundMul (ry, cc65_sin (sa));
x2 = x + tgi_imulround (rx, cc65_cos (sa));
y2 = y - tgi_imulround (ry, cc65_sin (sa));
tgi_line (x1, y1, x2, y2);
x1 = x2;
y1 = y2;