Apple-2-SW/lawless-legends
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Do sprite math strictly in Apple II coordinates.

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This commit is contained in:
Martin Haye 2013-11-03 09:47:44 -08:00
parent 40b66f083b
commit 41db1087ee
1 changed files with 17 additions and 6 deletions
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23
Platform/Apple/virtual/src/raycast/javascript/intcast.js
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@ -376,7 +376,7 @@ function intRenderSprites() {
var wLog256 = log2_w_w(256);
var wLogViewDist = log2_w_w(viewDist*256);
var wLogViewDist = log2_w_w(viewDist/8*256); // div by 8 to get to Apple II coords
for (var i=0;i<allSprites.length;i++) {
var sprite = allSprites[i];
@ -404,6 +404,8 @@ function intRenderSprites() {
var wLogDy = log2_w_w(uword(Math.abs(dy)*256));
var wRx = bSgnDx*bSgnCosT*pow2_w_w(wLogDx + wLogCosT - wLog256) -
bSgnDy*bSgnSinT*pow2_w_w(wLogDy + wLogSinT - wLog256);
// If sprite is behind the viewer, skip it.
if (wRx < 0) {
if (sprite.index == debugSprite)
console.log(" behind viewer.");
@ -426,18 +428,22 @@ function intRenderSprites() {
// x-position on screen
var bSgnRy = wRy < 0 ? -1 : 1;
var wX = bSgnRy * pow2_w_w(log2_w_w(Math.abs(wRy)*256) - wLogDist + log2_w_w(252 / 0.38268343236509034) - wLog256);
var wX = bSgnRy * pow2_w_w(log2_w_w(Math.abs(wRy)*256) - wLogDist + log2_w_w(252 / 8 / 0.38268343236509034) - wLog256);
if (sprite.index == debugSprite)
console.log(" wRx=" + wRx + ", wRy=" + wRy + ", wSize=" + wSize + ", wX=" + wX);
if (wX + wSize < 0) {
// If no pixels on screen, skip it
var spriteLeft = (screenWidth/8/2) + wX - (wSize/2);
var spriteRight = spriteLeft + wSize;
var spriteTop = ((screenHeight/8) - wSize) / 2;
if (spriteRight < 0) {
if (sprite.index == debugSprite)
console.log(" off-screen to left.");
sprite.visible = false;
sprite.img.style.display = "none";
continue;
}
else if (wX > screenWidth) {
else if (spriteLeft > (screenWidth/8)) {
if (sprite.index == debugSprite)
console.log(" off-screen to right.");
sprite.visible = false;
@ -445,10 +451,15 @@ function intRenderSprites() {
continue;
}
// Adjust from Apple II coordinates to PC coords (we render 8 pixels for each 1 Apple pix)
spriteLeft *= 8;
spriteTop *= 8;
wSize *= 8;
// Update the image with the calculated values
sprite.visible = true;
img.style.left = (screenWidth/2 + wX - wSize/2) + "px";
img.style.top = ((screenHeight-wSize)/2)+"px";
img.style.left = spriteLeft + "px";
img.style.top = spriteTop+"px";
img.style.width = wSize + "px";
img.style.height = wSize + "px";
img.style.zIndex = wSize;