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Working on integer sprite math.

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This commit is contained in:
Martin Haye 2013-10-19 13:12:12 -07:00
parent 6aedf0b72d
commit 20dd825927
1 changed files with 26 additions and 3 deletions
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29
Platform/Apple/virtual/src/raycast/javascript/intcast.js
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@ -367,6 +367,13 @@ function renderSprites() {
var sinT = Math.sin(-playerAngle()); var sinT = Math.sin(-playerAngle());
var cosT = Math.cos(-playerAngle()); var cosT = Math.cos(-playerAngle());
var bSgnSinT = (sinT < 0) ? -1 : 1;
var wLogSinT = log2_w_w(uword(Math.abs(sinT)*256));
var bSgnCosT = (cosT < 0) ? -1 : 1;
var wLogCosT = log2_w_w(uword(Math.abs(cosT)*256));
var wLog256 = log2_w_w(256);
for (var i=0;i<visibleSprites.length;i++) { for (var i=0;i<visibleSprites.length;i++) {
var sprite = visibleSprites[i]; var sprite = visibleSprites[i];
var img = sprite.img; var img = sprite.img;
@ -380,6 +387,20 @@ function renderSprites() {
var rx = (dx * cosT) - (dy * sinT); var rx = (dx * cosT) - (dy * sinT);
var ry = (dx * sinT) + (dy * cosT); var ry = (dx * sinT) + (dy * cosT);
var bSgnDx = (dx < 0) ? -1 : 1;
var wLogDx = log2_w_w(Math.abs(dx)*256);
var bSgnDy = (dy < 0) ? -1 : 1;
var wLogDy = log2_w_w(Math.abs(dy)*256);
var wRx = bSgnDx*bSgnCosT*pow2_w_w(wLogDx + wLogCosT - wLog256) -
bSgnDy*bSgnSinT*pow2_w_w(wLogDy + wLogSinT - wLog256);
var wRy = bSgnDx*bSgnSinT*pow2_w_w(wLogDx + wLogSinT - wLog256) +
bSgnDy*bSgnCosT*pow2_w_w(wLogDy + wLogCosT - wLog256);
console.log("Sprite " + sprite.index + ": rx=" + rx + ", wRx/256 = " + (wRx/256.0));
if (options & 1) {
rx = wRx / 256.0;
ry = wRy / 256.0;
}
var sqDist = rx*rx + ry*ry; var sqDist = rx*rx + ry*ry;
var dist = Math.sqrt(sqDist); var dist = Math.sqrt(sqDist);
@ -643,7 +664,8 @@ function log2_b_b(n) {
return tbl_log2_b_b[n]; return tbl_log2_b_b[n];
} }
// Fast pow2: take ubyte 5.3 fixed-point logarithm, produce ubyte: 2^n // Fast pow2: take ubyte 3.5 fixed-point logarithm, produce high byte: (2^n)>>8,
// that is, pow2_b_b(log2_b_b(x)+log2_b_b(y)) =~ (x*y)>>8
function pow2_b_b(n) { function pow2_b_b(n) {
return tbl_pow2_b_b[n]; return tbl_pow2_b_b[n];
} }
@ -685,6 +707,7 @@ function abs_w_w(n) {
function log2_w_w(n) { function log2_w_w(n) {
if (n == 0) if (n == 0)
return 0; return 0;
assert(n >= 1, "n must be non-negative for log2_w_w");
// Calculate the exponent, and leave mantissa in n. // Calculate the exponent, and leave mantissa in n.
var exp = 8; var exp = 8;
@ -698,7 +721,7 @@ function log2_w_w(n) {
} }
// Combine to form the result // Combine to form the result
return (exp << 8) | tbl_log2_w_w[n & 0xFF]; return uword((exp << 8) | tbl_log2_w_w[n & 0xFF]);
} }
// Table-based high precision pow2 - 16 bit to 16 bit // Table-based high precision pow2 - 16 bit to 16 bit
@ -710,7 +733,7 @@ function pow2_w_w(n)
result <<= (exp-8); result <<= (exp-8);
else if (exp < 8) else if (exp < 8)
result >>= (8-exp); result >>= (8-exp);
return result; return uword(result);
} }
function wallCalc(x, dist, bDir1, bDir2, bStep2) function wallCalc(x, dist, bDir1, bDir2, bStep2)