Felisp
84436a5ae0
http://my.svgalib.org/svgalib/svgalib-1.9.25.tar.gz http://my.svgalib.org/svgalib/
315 lines
7.9 KiB
C
315 lines
7.9 KiB
C
/*
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3DKIT version 1.2
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High speed 3D graphics and rendering library for Linux.
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Copyright (C) 1996, 1997 Paul Sheer psheer@icon.co.za
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public
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License as published by the Free Software Foundation; either
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version 2 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with this library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
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MA 02111-1307, USA
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*/
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/*
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File: wrapsurf.c
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Comments or suggestions welcome.
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This function wraps a bitmap over a surface.
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See wrapdemo.c for a demonstration of its use.
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Use bitmap data of only 256x512 (see wtriangle.c)
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although any region within the bitmap can be drawn
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to the full extents of the surface, so multiple
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small bitmaps can reside in one image and be
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used for different surfaces.
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*/
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#define TD_MULCONSTANT 4096
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#include <config.h>
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#include <math.h>
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#include <stdlib.h>
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#include <stdio.h>
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#ifndef DO_NOT_USE_VGALIB
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#include <vga.h>
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#endif
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#include <vgagl.h>
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#include "3dkit.h"
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/*global for holding a surface temporarily:*/
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extern TD_Short_Point *temp;
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static void xchg (int *a, int *b)
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{
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int t = *a;
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*a = *b;
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*b = t;
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}
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void TD_drawwrapsurface (TD_Solid * s, int which)
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{
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TD_Surface *surf = &s->surf[which];
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int w = surf->w;
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int l = surf->l;
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int bitmapwidth = surf->bitmapwidth;
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int bitmaplength = surf->bitmaplength;
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int i = 0, j = 0, k = 0, c = surf->mesh_color;
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void (*dl) (int, int, int, int, int) = s->draw_line;
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void (*dsw) (int, int, int, int,
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int, int, int, int,
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int, int, int, int, int,
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TD_tridata *) = s->draw_swtriangle;
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void (*dw) (int, int, int, int, int,
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int, int, int, int, int,
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int, int, int, int, int,
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TD_tridata *) = s->draw_wtriangle;
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int mesh;
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int d1, d2, d3, d4, d;
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int x1, y1, c1;
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int x2, y2, c2;
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int x3, y3, c3;
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int x4, y4, c4;
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int u1, v1;
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int u2, v2;
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int u3, v3;
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int u4, v4;
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int furthest, clockwise = 0;
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TD_tridata tri;
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tri.bitmap1 = surf->bitmap1;
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tri.bitmap2 = surf->bitmap2;
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if (s->option_flags & TDOPTION_ALL_SAME_RENDER)
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mesh = (s->render == TD_MESH_AND_SOLID);
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else
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mesh = (surf->render == TD_MESH_AND_SOLID);
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/*distance of four corners (numbered clockwise): */
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d1 = TD_finddistance (s, &surf->point[0]);
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d2 = TD_finddistance (s, &surf->point[w - 1]);
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d3 = TD_finddistance (s, &surf->point[w * l - 1]);
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d4 = TD_finddistance (s, &surf->point[w * (l - 1)]);
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/*find furthest point */
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furthest = 1;
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d = d1;
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if (d2 > d) {
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furthest = 2;
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d = d2;
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}
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if (d3 > d) {
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furthest = 3;
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d = d3;
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}
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if (d4 > d)
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furthest = 4;
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/*draw scanning from the furthest point to the second furthest point */
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/*there are eight possibilities: */
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switch (furthest) {
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case 1:
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if (d2 > d4) {
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clockwise = 0;
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for (j = 0; j < l; j++)
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for (i = 0; i < w; i++) {
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TD_translate (s, &surf->point[i + j * w], &temp[k]);
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temp[k].u = i * bitmapwidth / (w - 1);
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temp[k].v = j * bitmaplength / (l - 1);
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temp[k].c = TD_findcolor (s, &surf->point[i + j * w], which);
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k++;
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}
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} else {
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xchg (&l, &w);
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clockwise = 1;
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for (j = 0; j < l; j++)
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for (i = 0; i < w; i++) {
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TD_translate (s, &surf->point[i * l + j], &temp[k]);
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temp[k].u = j * bitmapwidth / (l - 1);
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temp[k].v = i * bitmaplength / (w - 1);
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temp[k].c = TD_findcolor (s, &surf->point[i * l + j], which);
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k++;
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}
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}
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break;
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case 2:
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if (d1 > d3) {
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clockwise = 1;
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for (j = 0; j < l; j++)
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for (i = w - 1; i >= 0; i--) {
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TD_translate (s, &surf->point[i + j * w], &temp[k]);
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temp[k].u = i * bitmapwidth / (w - 1);
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temp[k].v = j * bitmaplength / (l - 1);
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temp[k].c = TD_findcolor (s, &surf->point[i + j * w], which);
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k++;
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}
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} else {
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xchg (&l, &w);
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clockwise = 0;
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for (j = l - 1; j >= 0; j--)
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for (i = 0; i < w; i++) {
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TD_translate (s, &surf->point[i * l + j], &temp[k]);
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temp[k].u = j * bitmapwidth / (l - 1);
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temp[k].v = i * bitmaplength / (w - 1);
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temp[k].c = TD_findcolor (s, &surf->point[i * l + j], which);
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k++;
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}
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}
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break;
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case 3:
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if (d4 > d2) {
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clockwise = 0;
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for (j = l - 1; j >= 0; j--)
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for (i = w - 1; i >= 0; i--) {
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TD_translate (s, &surf->point[i + j * w], &temp[k]);
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temp[k].u = i * bitmapwidth / (w - 1);
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temp[k].v = j * bitmaplength / (l - 1);
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temp[k].c = TD_findcolor (s, &surf->point[i + j * w], which);
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k++;
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}
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} else {
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xchg (&l, &w);
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clockwise = 1;
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for (j = l - 1; j >= 0; j--)
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for (i = w - 1; i >= 0; i--) {
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TD_translate (s, &surf->point[i * l + j], &temp[k]);
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temp[k].u = j * bitmapwidth / (l - 1);
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temp[k].v = i * bitmaplength / (w - 1);
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temp[k].c = TD_findcolor (s, &surf->point[i * l + j], which);
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k++;
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}
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}
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break;
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case 4:
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if (d3 > d1) {
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clockwise = 1;
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for (j = l - 1; j >= 0; j--)
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for (i = 0; i < w; i++) {
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TD_translate (s, &surf->point[i + j * w], &temp[k]);
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temp[k].u = i * bitmapwidth / (w - 1);
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temp[k].v = j * bitmaplength / (l - 1);
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temp[k].c = TD_findcolor (s, &surf->point[i + j * w], which);
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k++;
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}
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} else {
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xchg (&l, &w);
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clockwise = 0;
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for (j = 0; j < l; j++)
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for (i = w - 1; i >= 0; i--) {
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TD_translate (s, &surf->point[i * l + j], &temp[k]);
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temp[k].u = j * bitmapwidth / (l - 1);
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temp[k].v = i * bitmaplength / (w - 1);
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temp[k].c = TD_findcolor (s, &surf->point[i * l + j], which);
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k++;
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}
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}
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break;
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}
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if (!surf->backfacing)
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clockwise += 2; /*Otherwise a different bitmap on either side*/
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tri.bf = clockwise;
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for (k = 0, j = 0; j < l - 1; j++, k++) {
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for (i = 0; i < w - 1; i++, k++) {
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/*define the grid square we are currently drawing: */
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x1 = temp[k].x;
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y1 = temp[k].y;
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u1 = temp[k].u;
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v1 = temp[k].v;
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c1 = temp[k].c;
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x2 = temp[k + 1].x;
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y2 = temp[k + 1].y;
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u2 = temp[k + 1].u;
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v2 = temp[k + 1].v;
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c2 = temp[k + 1].c;
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x3 = temp[k + w + 1].x;
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y3 = temp[k + w + 1].y;
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u3 = temp[k + w + 1].u;
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v3 = temp[k + w + 1].v;
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c3 = temp[k + w + 1].c;
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x4 = temp[k + w].x;
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y4 = temp[k + w].y;
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u4 = temp[k + w].u;
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v4 = temp[k + w].v;
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c4 = temp[k + w].c;
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/*draw with two triangles */
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if (furthest & 1) { /*draw with hypotenuse from point 1 to point 3*/
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if (s->option_flags & TDOPTION_FLAT_TRIANGLE) {
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c1 = (c1 + c2 + c3 + c4) >> 2;
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(*dsw) (x1, y1, u1, v1, x2, y2, u2, v2, x3, y3, u3, v3, c1, &tri);
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(*dsw) (x1, y1, u1, v1, x3, y3, u3, v3, x4, y4, u4, v4, c1, &tri);
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} else {
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(*dw) (x1, y1, u1, v1, c1, x2, y2, u2, v2, c2, x3, y3, u3, v3, c3, &tri);
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(*dw) (x1, y1, u1, v1, c1, x3, y3, u3, v3, c3, x4, y4, u4, v4, c4, &tri);
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}
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} else { /*draw with hypotenuse from point 2 to point 4*/
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if (s->option_flags & TDOPTION_FLAT_TRIANGLE) {
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c1 = (c1 + c2 + c3 + c4) >> 2;
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(*dsw) (x1, y1, u1, v1, x2, y2, u2, v2, x4, y4, u4, v4, c1, &tri);
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(*dsw) (x2, y2, u2, v2, x3, y3, u3, v3, x4, y4, u4, v4, c1, &tri);
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} else {
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(*dw) (x1, y1, u1, v1, c1, x2, y2, u2, v2, c2, x4, y4, u4, v4, c4, &tri);
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(*dw) (x2, y2, u2, v2, c2, x3, y3, u3, v3, c3, x4, y4, u4, v4, c4, &tri);
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}
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}
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if (mesh) {
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(*dl) (x1, y1, x2, y2, c);
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(*dl) (x1, y1, x4, y4, c);
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}
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}
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if (mesh)
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(*dl) (temp[k + w].x, temp[k + w].y, temp[k].x, temp[k].y, c);
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}
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if (mesh) {
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for (i = 0; i < w - 1; i++, k++)
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(*dl) (temp[k + 1].x, temp[k + 1].y, temp[k].x, temp[k].y, c);
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}
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}
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