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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 1 | pmbaty | 1 | /* |
| 2 | * This file is part of the DXX-Rebirth project <https://www.dxx-rebirth.com/>. |
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| 3 | * It is copyright by its individual contributors, as recorded in the |
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| 4 | * project's Git history. See COPYING.txt at the top level for license |
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| 5 | * terms and a link to the Git history. |
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| 6 | */ |
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| 7 | /* |
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| 8 | * |
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| 9 | * Routines for point definition, rotation, etc. |
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| 10 | * |
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| 11 | */ |
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| 12 | |||
| 13 | |||
| 14 | #include "3d.h" |
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| 15 | #include "globvars.h" |
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| 16 | |||
| 17 | namespace dcx { |
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| 18 | |||
| 19 | //code a point. fills in the p3_codes field of the point, and returns the codes |
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| 20 | ubyte g3_code_point(g3s_point &p) |
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| 21 | { |
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| 22 | ubyte cc=0; |
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| 23 | |||
| 24 | if (p.p3_x > p.p3_z) |
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| 25 | cc |= CC_OFF_RIGHT; |
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| 26 | |||
| 27 | if (p.p3_y > p.p3_z) |
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| 28 | cc |= CC_OFF_TOP; |
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| 29 | |||
| 30 | if (p.p3_x < -p.p3_z) |
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| 31 | cc |= CC_OFF_LEFT; |
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| 32 | |||
| 33 | if (p.p3_y < -p.p3_z) |
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| 34 | cc |= CC_OFF_BOT; |
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| 35 | |||
| 36 | if (p.p3_z < 0) |
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| 37 | cc |= CC_BEHIND; |
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| 38 | |||
| 39 | return p.p3_codes = cc; |
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| 40 | |||
| 41 | } |
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| 42 | |||
| 43 | //rotates a point. returns codes. does not check if already rotated |
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| 44 | ubyte g3_rotate_point(g3s_point &dest,const vms_vector &src) |
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| 45 | { |
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| 46 | const auto tempv = vm_vec_sub(src,View_position); |
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| 47 | vm_vec_rotate(dest.p3_vec,tempv,View_matrix); |
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| 48 | dest.p3_flags = 0; //no projected |
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| 49 | return g3_code_point(dest); |
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| 50 | } |
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| 51 | |||
| 52 | //checks for overflow & divides if ok, fillig in r |
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| 53 | //returns true if div is ok, else false |
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| 54 | int checkmuldiv(fix *r,fix a,fix b,fix c) |
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| 55 | { |
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| 56 | quadint q,qt; |
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| 57 | q.q = 0; |
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| 58 | fixmulaccum(&q,a,b); |
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| 59 | |||
| 60 | qt = q; |
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| 61 | if (qt.high < 0) |
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| 62 | fixquadnegate(&qt); |
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| 63 | |||
| 64 | qt.high *= 2; |
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| 65 | if (qt.low > 0x7fff) |
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| 66 | qt.high++; |
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| 67 | |||
| 68 | if (qt.high >= c) |
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| 69 | return 0; |
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| 70 | else { |
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| 71 | *r = static_cast<int32_t>(q.q / static_cast<int64_t>(c)); |
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| 72 | return 1; |
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| 73 | } |
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| 74 | } |
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| 75 | |||
| 76 | //projects a point |
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| 77 | void g3_project_point(g3s_point &p) |
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| 78 | { |
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| 79 | #ifndef __powerc |
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| 80 | fix tx,ty; |
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| 81 | |||
| 82 | if ((p.p3_flags & PF_PROJECTED) || (p.p3_codes & CC_BEHIND)) |
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| 83 | return; |
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| 84 | |||
| 85 | if (checkmuldiv(&tx,p.p3_x,Canv_w2,p.p3_z) && checkmuldiv(&ty,p.p3_y,Canv_h2,p.p3_z)) { |
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| 86 | p.p3_sx = Canv_w2 + tx; |
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| 87 | p.p3_sy = Canv_h2 - ty; |
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| 88 | p.p3_flags |= PF_PROJECTED; |
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| 89 | } |
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| 90 | else |
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| 91 | p.p3_flags |= PF_OVERFLOW; |
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| 92 | #else |
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| 93 | double fz; |
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| 94 | |||
| 95 | if ((p.p3_flags & PF_PROJECTED) || (p.p3_codes & CC_BEHIND)) |
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| 96 | return; |
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| 97 | |||
| 98 | if ( p.p3_z <= 0 ) { |
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| 99 | p.p3_flags |= PF_OVERFLOW; |
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| 100 | return; |
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| 101 | } |
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| 102 | |||
| 103 | fz = f2fl(p.p3_z); |
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| 104 | p.p3_sx = fl2f(fCanv_w2 + (f2fl(p.p3_x)*fCanv_w2 / fz)); |
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| 105 | p.p3_sy = fl2f(fCanv_h2 - (f2fl(p.p3_y)*fCanv_h2 / fz)); |
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| 106 | |||
| 107 | p.p3_flags |= PF_PROJECTED; |
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| 108 | #endif |
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| 109 | } |
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| 110 | |||
| 111 | //from a 2d point, compute the vector through that point |
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| 112 | void g3_point_2_vec(vms_vector &v,short sx,short sy) |
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| 113 | { |
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| 114 | vms_vector tempv; |
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| 115 | vms_matrix tempm; |
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| 116 | |||
| 117 | tempv.x = fixmuldiv(fixdiv((sx<<16) - Canv_w2,Canv_w2),Matrix_scale.z,Matrix_scale.x); |
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| 118 | tempv.y = -fixmuldiv(fixdiv((sy<<16) - Canv_h2,Canv_h2),Matrix_scale.z,Matrix_scale.y); |
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| 119 | tempv.z = f1_0; |
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| 120 | |||
| 121 | vm_vec_normalize(tempv); |
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| 122 | tempm = vm_transposed_matrix(Unscaled_matrix); |
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| 123 | vm_vec_rotate(v,tempv,tempm); |
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| 124 | } |
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| 125 | |||
| 126 | void g3_rotate_delta_vec(vms_vector &dest,const vms_vector &src) |
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| 127 | { |
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| 128 | vm_vec_rotate(dest,src,View_matrix); |
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| 129 | } |
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| 130 | |||
| 131 | ubyte g3_add_delta_vec(g3s_point &dest,const g3s_point &src,const vms_vector &deltav) |
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| 132 | { |
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| 133 | vm_vec_add(dest.p3_vec,src.p3_vec,deltav); |
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| 134 | dest.p3_flags = 0; //not projected |
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| 135 | return g3_code_point(dest); |
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| 136 | } |
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| 137 | |||
| 138 | //calculate the depth of a point - returns the z coord of the rotated point |
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| 139 | fix g3_calc_point_depth(const vms_vector &pnt) |
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| 140 | { |
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| 141 | quadint q; |
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| 142 | q.q = 0; |
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| 143 | fixmulaccum(&q,(pnt.x - View_position.x),View_matrix.fvec.x); |
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| 144 | fixmulaccum(&q,(pnt.y - View_position.y),View_matrix.fvec.y); |
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| 145 | fixmulaccum(&q,(pnt.z - View_position.z),View_matrix.fvec.z); |
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| 146 | return fixquadadjust(&q); |
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| 147 | } |
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| 148 | |||
| 149 | } |