Bitmap Perspective transformation

Import flash.geom.*;
var photo:sprite=new Sprite ();
AddChild (photo);
IMG is a picture class that inherits from BitmapData
var bitmapsource = new Img (400,300);
var showline = true;
var inbitmapwidth = 1/bitmapsource.width;
var inbitmapheight = 1/bitmapsource.height;
var bitmapwidth = bitmapsource.width;
var bitmapheight = bitmapsource.height;
Bitmap transformation distance of mouse
var Bitmapmtrx = new Matrix ();
var Subbitmapmtix = new Matrix ();
Stage width Variable declaration
var stwidth = 550;
var stheight = 400;
Varōx = STWIDTH/2;
Varōy = STHEIGHT/2;
Focal length
var focus = 80;
Camera angle Variable
var Angu = 0;
var ANGV = 0;
Number of fine segments
var subdiv = 5;
var subdivpic = subdiv* (Subdiv-1);
var subdivvy = new Array ();
var subdivvx = new Array ();
var subdivvz = new Array ();
var subdivx = new Array ();
var subdivy = new Array ();
var subdivenable = new Array ();
var Mtrx = new Array ();
var mtrx2 = new Array ();
Subdivide bitmap x and y within the map
var subdivmapx = new Array ();
var subdivmapy = new Array ();
var subdivwidth = bitmapsource.width/(Subdiv-1);
var subdivheight = bitmapsource.height/(Subdiv-1);
for (var i = 0; i<subdiv; i++) {
for (var j = 0; j<subdiv; j + +) {
Subdivmapx.push (J*subdivwidth);
Subdivmapy.push (I*subdivheight);
}
}
//
for (var h = 0; h<subdivpic; h++) {
Mtrx.push (New Flash.geom.Matrix ());
Mtrx2.push (New Flash.geom.Matrix ());
Subdivvy.push (New Array (subdivpic));
Subdivvx.push (New Array (subdivpic));
Subdivvz.push (New Array (subdivpic));
Subdivx.push (New Array (subdivpic));
Subdivy.push (New Array (subdivpic));
Subdivenable.push (New Array (subdivpic));
}
var mtrxsx = subdivwidth/bitmapwidth;
var mtrxsy = subdivheight/bitmapheight;
var mtrxsxy = subdivwidth/bitmapheight;
var mtrxsyx = subdivheight/bitmapwidth;
for (var m = 0; m<subdiv-1; ++m) {
for (var n = 0; n<subdiv-1; ++n) {
var SubID = N+m*subdiv;
var mtrxtx = subdivmapx[subdiv*m+n];
var mtrxty = subdivmapy[subdiv*m+n];
Mtrx[subid].tx = MTRXTX;
Mtrx[subid].ty = mtrxty;
MTRX[SUBID].A = MTRXSX;
mtrx[subid].b = 0;
MTRX[SUBID].C = Mtrxsxy;
MTRX[SUBID].D = Mtrxsy;
Mtrx[subid].invert ();
Mtrx2[subid].tx = MTRXTX;
Mtrx2[subid].ty = mtrxty;
MTRX2[SUBID].A = MTRXSX;
mtrx2[subid].b = Mtrxsyx;
mtrx2[subid].c = 0;
MTRX2[SUBID].D = Mtrxsy;
Mtrx2[subid].invert ();
}
}
var mtrxa = mtrx[0].a;
var mtrxb = mtrx[0].b;
var mtrxc = mtrx[0].c;
var mtrxd = mtrx[0].d;
var mtrx2a = mtrx2[0].a;
var mtrx2b = mtrx2[0].b;
var mtrx2c = mtrx2[0].c;
var mtrx2d = mtrx2[0].d;
Initial spatial position of each bitmap subdivision node in the regular 3D viewport space
function Fun6 (Bitmapno, New19, NEW20, New21, New22, new25, New23, new26, New24, new27) {
var new15 = Subdiv-1 >> 1;
for (var i = 0; i<subdiv; i++) {
for (var j = 0; j<subdiv; j + +) {
var SubID = J+i*subdiv;
Subdivvy[bitmapno][subid] = new19*new15+new22* (J-NEW15) +new25* (I-NEW15);
Subdivvx[bitmapno][subid] = new20*new15+new23* (J-NEW15) +new26* (I-NEW15);
Subdivvz[bitmapno][subid] = new21*new15+new24* (J-NEW15) +new27* (I-NEW15);
Trace (subdivvy[bitmapno][subid]+ "/" +subdivvx[bitmapno][subid]+ "/" +subdivvz[bitmapno][subid]);
}
}
}
Fun6 (0,1,0,0,0,0,-1,0,0,-1);
function Fun7 (bitmapno) {
for (var i = 0; i<subdivpic; i++) {
This is the core part: The coordinate transformation operation of subdivision map vertex in camera coordinate space _loc5 is z value, and the two equations of _LOC5 and _loc6 are the simplification of space vector distance matrix calculation.
var _loc6 = cos_angu*subdivvy[bitmapno][i]+sin_angu*subdivvx[bitmapno][i];
var _loc5 = cos_angv*_loc6+sin_angv*subdivvz[bitmapno][i];
If the vertex is in front of the view, the projection is calculated
if (_loc5>=0.1) {
var _loc7 = focus/_loc5;
Calculate the x,y of a projection
Subdivx[bitmapno][i] = (sin_angu*subdivvy[bitmapno][i]-cos_angu*subdivvx[bitmapno][i]) *_loc7+ox;
Subdivy[bitmapno][i] = (sin_angv*_loc6-cos_angv*subdivvz[bitmapno][i]) *_loc7+oy;
if (subdivx[bitmapno][i]>0 && subdivx[bitmapno][i]<stwidth && subdivy[bitmapno][i]>0 & & Subdivy[bitmapno][i]<stheight) {
Subdivenable[bitmapno][i] = 1;
} else {
Subdivenable[bitmapno][i] = 0;
}
}
}
}
var subdivv = Subdiv-1;
function render () {
for (var i = 0; i<6; i++) {
Fun7 (i);
for (var j = 0; j<subdivv; ++j) {
for (var k = 0; k<subdivv; k++) {
var pointa = K+j*subdiv;
var pointc = k + (j+1) *subdiv;
var pointb = pointa+1;
var pointd = pointc+1;
var _loc2 = Subdivenable[i][pointa]+subdivenable[i][pointd]+subdivenable[i][pointb];
var _loc3 = Subdivenable[i][pointa]+subdivenable[i][pointd]+subdivenable[i][pointc];
If the subdivision surface has 1 vertices on the screen, the surface is rendered
if (_loc2>0) {
Calculation of stretching distance matrix of subdivision surface
SUBBITMAPMTIX.A = Mtrxa;
subbitmapmtix.b = MTRXB;
SUBBITMAPMTIX.C = MTRXC;
SUBBITMAPMTIX.D = Mtrxd;
Subbitmapmtix.tx = MTRX[POINTA].TX;
Subbitmapmtix.ty = Mtrx[pointa].ty;
Renderbitmap (I,subdivx[i][pointa],subdivy[i][pointa],subdivx[i][pointb],subdivy[i][pointb],subdivx[i][pointd], Subdivy[i][pointd],subbitmapmtix);
}
If the subdivision surface has 1 vertices on the screen, the surface is rendered
if (_loc3>0) {
Calculation of stretching distance matrix of subdivision surface
SUBBITMAPMTIX.A = mtrx2a;
subbitmapmtix.b = mtrx2b;
SUBBITMAPMTIX.C = mtrx2c;
SUBBITMAPMTIX.D = mtrx2d;
Subbitmapmtix.tx = MTRX2[POINTA].TX;
Subbitmapmtix.ty = Mtrx2[pointa].ty;
Renderbitmap (I,SUBDIVX[I][POINTA],SUBDIVY[I][POINTA],SUBDIVX[I][POINTD],SUBDIVY[I][POINTD],SUBDIVX[I][POINTC], Subdivy[i][pointc],subbitmapmtix);
}
}
}
}
}
function Renderbitmap (Bitmapno, point1x, point1y, point2x, point2y, point3x, point3y, Subbitmapmtix) {
Subdivision surface mapping Distance matrix calculation
THIS.BITMAPMTRX.A = (point2x-point1x) *inbitmapwidth;
this.bitmapmtrx.b = (point2y-point1y) *inbitmapwidth;
THIS.BITMAPMTRX.C = (point3x-point1x) *inbitmapheight;
THIS.BITMAPMTRX.D = (point3y-point1y) *inbitmapheight;
This.bitmapMtrx.tx = point1x;
This.bitmapMtrx.ty = point1y;
Subbitmapmtix.concat (THIS.BITMAPMTRX);
Texture rendering
This.photo.graphics.beginBitmapFill (Bitmapsource,subbitmapmtix,false,false);
if (ShowLine = = True) {
This.photo.graphics.lineStyle (1,0x000000,100);
}
This.photo.graphics.moveTo (POINT1X,POINT1Y);
This.photo.graphics.lineTo (POINT2X,POINT2Y);
This.photo.graphics.lineTo (POINT3X,POINT3Y);
This.photo.graphics.endFill ();
}//Initial rendering
Photo.graphics.clear ();
var Cos_angu = Math.Cos (Angu);
var Sin_angu = Math.sin (Angu);
var COS_ANGV = Math.Cos (ANGV);
var SIN_ANGV = Math.sin (ANGV);
var dx;
var dy;
Stage.addeventlistener (Mouseevent.mouse_down,onmousedownhandler);
Stage.addeventlistener (Mouseevent.mouse_up,onmouseuphandler);
function Onmousedownhandler (evt:mouseevent): void {
Stage.addeventlistener (Event.enter_frame,onenterframehandler);
DX = MouseX;
dy = Mousey;
}
function Onenterframehandler (evt:event): void {
var xwidth = MOUSEX-DX;
var ywidth = Mousey-dy;
if (xwidth!= 0 | | | ywidth!= 0) {
Photo.graphics.clear ();
Angu = angu-xwidth*0.001;
ANGV = angv-ywidth*0.001;
Cos_angu = Math.Cos (Angu);
Sin_angu = Math.sin (Angu);
COS_ANGV = Math.Cos (ANGV);
SIN_ANGV = Math.sin (ANGV);
Render ();
}
}
function Onmouseuphandler (evt:mouseevent): void {
Stage.removeeventlistener (Event.enter_frame,onenterframehandler);
Photo.graphics.clear ();
Render ();
}
Render ();