gl_warp.pas

雷神之锤2(Quake2)Delphi源码

  v, av    : vec3_t;
  s, t, dv : float;
//	float	*vp;
  vp : pfloat;//vec3_p;
begin
  Inc(c_sky);

(*#if 0
glBegin (GL_POLYGON);
for (i=0 ; i<nump ; i++, vecs+=3)
{
	VectorAdd(vecs, r_origin, v);
	qglVertex3fv (v);
}
glEnd();
return;
#endif*)

  // decide which face it maps to
  VectorCopy (vec3_origin, v);
//{Y}  for (i=0, vp=vecs ; i<nump ; i++, vp+=3)
  vp := @vecs;
  for i:=0 to nump-1 do
  begin
    VectorAdd (vp, v, v);
    Inc(vp, 3);  //666 - it's EQUAL: "@vp := @vp +sizeof(vp^)"  -OR-  "@vp := @vp + 3*sizeof(float)" 
  end;//for???

  av[0] := abs(v[0]);
  av[1] := abs(v[1]);
  av[2] := abs(v[2]);
  if (av[0] > av[1]) AND (av[0] > av[2])
  then
    if (v[0] < 0)
    then axis := 1
    else axis := 0
  else
    if (av[1] > av[2]) AND (av[1] > av[0])
    then
      if (v[1] < 0)
      then axis := 3
      else axis := 2
    else
      if (v[2] < 0)
      then axis := 5
      else axis := 4;

  // project new texture coords
//{Y}  for (i=0 ; i<nump ; i++, vecs+=3)
  for i:=0 to nump-1 do
(*
Y-666 : tmp_code:
 - vecs_ := @vecs;
 - Inc(vecs_)  OR  Inc(vecs_, 3)   ---> 3*3 = 9 float elements
*)
  begin
        j := vec_to_st[axis][2];
        if (j > 0)
        then dv := vecs[j - 1]
        else dv := -vecs[-j - 1];
        if (dv < 0.001) then
          Continue;   // don't divide by zero
        j := vec_to_st[axis][0];
        if (j < 0)
        then s := -vecs[-j -1] / dv
        else s := vecs[j-1] / dv;
        j := vec_to_st[axis][1];
        if (j < 0)
        then t := -vecs[-j -1] / dv
        else t := vecs[j-1] / dv;

        if (s < skymins[0][axis]) then
          skymins[0][axis] := s;
        if (t < skymins[1][axis]) then
          skymins[1][axis] := t;
        if (s > skymaxs[0][axis]) then
          skymaxs[0][axis] := s;
        if (t > skymaxs[1][axis]) then
          skymaxs[1][axis] := t;

  end;//for???
end;//procedure

const
  ON_EPSILON	 = 0.1;	// point on plane side epsilon
  MAX_CLIP_VERTS = 64;
procedure ClipSkyPolygon (nump : integer; vecs : vec3_t; stage : integer);
var
{	float	*norm;
	float	*v;}
norm : vec3_t;
v : vec3_p{pfloat};
vecs_ : vec3_p;

  front, back : qboolean;
  d, e        : float;
  dists       : array [0..MAX_CLIP_VERTS-1] of float;
  sides       : array [0..MAX_CLIP_VERTS-1] of integer;
//	vec3_t	newv[2][MAX_CLIP_VERTS];
  newv        : array [0..1, 0..MAX_CLIP_VERTS-1] of vec3_t;
  newc        : array [0..1] of integer;
  i, j        : integer;
begin
  if (nump > MAX_CLIP_VERTS-2) then
    ri.Sys_Error (ERR_DROP, 'ClipSkyPolygon: MAX_CLIP_VERTS', []);
  if (stage = 6) then
  begin
    // fully clipped, so draw it
    DrawSkyPolygon (nump, vecs);
    Exit;
  end;

  front := false;
  back  := false;
  norm := skyclip[stage];
//{Y}  for (i=0, v = vecs ; i<nump ; i++, v+=3)
  v := @vecs;
  for i:=0 to nump-1 do
  begin
        d := DotProduct (v^, norm);
        if (d > ON_EPSILON)
        then begin
          front := true;
          sides[i] := SIDE_FRONT;
        end
        else
          if (d < -ON_EPSILON)
          then begin
            back := true;
            sides[i] := SIDE_BACK;
          end
          else sides[i] := SIDE_ON;
        dists[i] := d;

    Inc(v, 3); //666
  end;//for???

//  if (!front || !back) then
  if (not front) or (not back) then
  begin
    // not clipped
    ClipSkyPolygon (nump, vecs, stage+1);
    Exit;
  end;

  // clip it
  sides[i] := sides[0];
  dists[i] := dists[0];
//  VectorCopy (vecs, (vecs+(i*3)));
vecs_ := @vecs;
Inc(vecs_, i);  //OR- i*3
VectorCopy (vecs, vecs_^);


//  newc[0] = newc[1] = 0;
  newc[1] := 0;
  newc[0] := newc[1];

//{Y}  for (i=0, v = vecs ; i<nump ; i++, v+=3)
  v := @vecs;
  for i:=0 to nump-1 do
  begin
        Case (sides[i]) of
          SIDE_FRONT: begin
                        VectorCopy (v^, newv[0][newc[0]]);
                        Inc(newc[0]);
                      end;
          SIDE_BACK:  begin
                        VectorCopy (v^, newv[1][newc[1]]);
                        Inc(newc[1]);
                      end;
          SIDE_ON:    begin
                        VectorCopy (v^, newv[0][newc[0]]);
                        Inc(newc[0]);
                        VectorCopy (v^, newv[1][newc[1]]);
                        Inc(newc[1]);
                      end;
        end;//case

        if (sides[i] = SIDE_ON) OR (sides[i+1] = SIDE_ON) OR (sides[i+1] = sides[i]) then
          Continue;

        d := dists[i] / (dists[i] - dists[i+1]);
        for j:=0 to 2 do
        begin
          e := v[j] + d*(v[j+3] - v[j]);
          newv[0][newc[0]][j] := e;
          newv[1][newc[1]][j] := e;
        end;
        Inc(newc[0]);
        Inc(newc[1]);

    Inc(v); //666    
  end;//for???

  // continue
  ClipSkyPolygon (newc[0], newv[0][0], stage+1);
  ClipSkyPolygon (newc[1], newv[1][0], stage+1);
end;//procedure

{*
=================
R_AddSkySurface
=================
*}
procedure R_AddSkySurface (fa : msurface_t);
var
  i     : integer;
  verts : array [0..MAX_CLIP_VERTS-1] of vec3_t;
//	glpoly_t	*p;
  p     : glpoly_p;
begin
  // calculate vertex values for sky box
(*//Y: change C2Pas-code
	for (p=fa->polys ; p ; p=p->next)
	{
		for (i=0 ; i<p->numverts ; i++)
		{
			VectorSubtract (p->verts[i], r_origin, verts[i]);
		}
		ClipSkyPolygon (p->numverts, verts[0], 0);
	}
*)
  //Y: change C2Pas-code
  p := fa.polys;
  while p<>Nil do  //while Assigned(p) do
  begin
    for i:=0 to p.numverts-1 do
      VectorSubtract (@p.verts[i], r_origin, verts[i]);
    ClipSkyPolygon (p.numverts, verts[0], 0);
    p := p.next;
  end;
end;//procedure

{*
==============
R_ClearSkyBox
==============
*}
procedure R_ClearSkyBox;
var
  i : integer;
begin
  for i:=0 to 5 do
  begin
    skymins[0][i] := 9999;
    skymins[1][i] := 9999;
    skymaxs[0][i] := -9999;
    skymaxs[1][i] := -9999;
  end;
end;//procedure

procedure MakeSkyVec (s, t : float; axis : integer);
var
  v, b  : vec3_t;
  j, k  : integer;
begin
  b[0] := s*2300;
  b[1] := t*2300;
  b[2] := 2300;

  for j:=0 to 2 do
  begin
    k := st_to_vec[axis][j];
    if (k < 0)
    then v[j] := -b[-k - 1]
    else v[j] := b[k - 1];
  end;

  // avoid bilerp seam
  s := (s+1)*0.5;
  t := (t+1)*0.5;

  if (s < sky_min)
  then s := sky_min
  else
    if (s > sky_max) then
      s := sky_max;

  if (t < sky_min)
  then t := sky_min
  else
    if (t > sky_max) then
      t := sky_max;

  t := 1.0 - t;
  qglTexCoord2f (s, t);
  qglVertex3fv (@v);
end;//procedure

{*
==============
R_DrawSkyBox
==============
*}
const
  skytexorder : array [0..5] of integer = (0,2,1,3,4,5);
procedure R_DrawSkyBox;
var
  i : integer;
begin
(*#if 0
qglEnable (GL_BLEND);
GL_TexEnv( GL_MODULATE );
qglColor4f (1,1,1,0.5);
qglDisable (GL_DEPTH_TEST);
#endif*)

  if (skyrotate <> 0) then
  begin
    // check for no sky at all
    for i:=0 to 5 do
      if (skymins[0][i] < skymaxs[0][i]) AND (skymins[1][i] < skymaxs[1][i]) then
        Break;
    if (i = 6) then
      Exit; // nothing visible
  end;

  qglPushMatrix ();
    qglTranslatef (r_origin[0], r_origin[1], r_origin[2]);
    qglRotatef (r_newrefdef.time * skyrotate, skyaxis[0], skyaxis[1], skyaxis[2]);

    for i:=0 to 5 do
    begin
      if (skyrotate <> 0) then
      begin
        // hack, forces full sky to draw when rotating
        skymins[0][i] := -1;
        skymins[1][i] := -1;
        skymaxs[0][i] := 1;
        skymaxs[1][i] := 1;
       end;

      if (skymins[0][i] >= skymaxs[0][i]) OR (skymins[1][i] >= skymaxs[1][i]) then
        Continue;

      GL_Bind (sky_images[skytexorder[i]].texnum);

      qglBegin (GL_QUADS);
        MakeSkyVec (skymins[0][i], skymins[1][i], i);
        MakeSkyVec (skymins[0][i], skymaxs[1][i], i);
        MakeSkyVec (skymaxs[0][i], skymaxs[1][i], i);
        MakeSkyVec (skymaxs[0][i], skymins[1][i], i);
      qglEnd ();
    end;//for i
  qglPopMatrix ();

(*#if 0
glDisable (GL_BLEND);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glColor4f (1,1,1,0.5);
glEnable (GL_DEPTH_TEST);
#endif*)
end;//procedure

{*
============
R_SetSky
============
*}
const
// 3dstudio environment map names
  suf : array [0..5] of PChar = ('rt', 'bk', 'lf', 'ft', 'up', 'dn');
procedure R_SetSky (name : PChar; rotate : float; axis : vec3_t); cdecl; //for gl_rmain
var
  i        : integer;
  pathname : array [0..MAX_QPATH] of char;
begin
  strncpy (skyname, name, sizeof(skyname)-1);
  skyrotate := rotate;
  VectorCopy (axis, skyaxis);

  for i:=0 to 5 do
  begin
    // chop down rotating skies for less memory
    if (gl_skymip.value <> 0) OR (skyrotate <> 0) then
//      gl_picmip.value++;
      gl_picmip.value := gl_picmip.value +1;

    if Assigned(qglColorTableEXT) AND (gl_ext_palettedtexture.value <> 0)
    then Com_sprintf (pathname, sizeof(pathname), 'env/%s%s.pcx', [skyname, suf[i]])
    else Com_sprintf (pathname, sizeof(pathname), 'env/%s%s.tga', [skyname, suf[i]]);

    sky_images[i] := GL_FindImage (pathname, it_sky);
    if (sky_images[i] <> Nil) then
      sky_images[i] := r_notexture;

    if (gl_skymip.value <> 0) OR (skyrotate <> 0)
    then begin
      // take less memory
//      gl_picmip.value--;
      gl_picmip.value := gl_picmip.value -1;
      sky_min :=   1.0/256;
      sky_max := 255.0/256;
    end
    else begin
      sky_min :=   1.0/512;
      sky_max := 511.0/512;
    end;
  end;//for i
end;//procedure

// End of file
end.


My current problems:
--------------------
1,2,3)
  - POINTERs - float, pfloat, vec3t, vec3_p
  - sample cycle kind of: ...  --> Y: gl_rsurf.pas
  - Math_procedure Xxx(); overload;

4) OK!