1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/mglrast.c	Mon Nov 21 06:14:01 2011 +0200
     1.3 @@ -0,0 +1,163 @@
     1.4 +/*
     1.5 +256-color 3D graphics hack for real-mode DOS.
     1.6 +Copyright (C) 2011  John Tsiombikas <nuclear@member.fsf.org>
     1.7 +
     1.8 +This program is free software: you can redistribute it and/or modify
     1.9 +it under the terms of the GNU General Public License as published by
    1.10 +the Free Software Foundation, either version 3 of the License, or
    1.11 +(at your option) any later version.
    1.12 +
    1.13 +This program is distributed in the hope that it will be useful,
    1.14 +but WITHOUT ANY WARRANTY; without even the implied warranty of
    1.15 +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    1.16 +GNU General Public License for more details.
    1.17 +
    1.18 +You should have received a copy of the GNU General Public License
    1.19 +along with this program.  If not, see <http://www.gnu.org/licenses/>.
    1.20 +*/
    1.21 +#include <stdio.h>
    1.22 +#include <stdlib.h>
    1.23 +#include <string.h>
    1.24 +#include <assert.h>
    1.25 +#include "mingl.h"
    1.26 +#include "mglimpl.h"
    1.27 +
    1.28 +
    1.29 +static struct vertex *vleft, *vright;
    1.30 +static struct framebuffer *fb;
    1.31 +static struct state *st;
    1.32 +
    1.33 +
    1.34 +#define SCAN_EDGE scan_edge_flat
    1.35 +#define SCAN_LINE scan_line_flat
    1.36 +#undef INTERP_DEPTH
    1.37 +#undef INTERP_ENERGY
    1.38 +#include "scantmpl.h"
    1.39 +#undef SCAN_EDGE
    1.40 +#undef SCAN_LINE
    1.41 +
    1.42 +#define SCAN_EDGE scan_edge_z
    1.43 +#define SCAN_LINE scan_line_z
    1.44 +#define INTERP_DEPTH
    1.45 +#undef INTERP_ENERGY
    1.46 +#include "scantmpl.h"
    1.47 +#undef SCAN_EDGE
    1.48 +#undef SCAN_LINE
    1.49 +
    1.50 +#define SCAN_EDGE scan_edge_e
    1.51 +#define SCAN_LINE scan_line_e
    1.52 +#undef INTERP_DEPTH
    1.53 +#define INTERP_ENERGY
    1.54 +#include "scantmpl.h"
    1.55 +#undef SCAN_EDGE
    1.56 +#undef SCAN_LINE
    1.57 +
    1.58 +#define SCAN_EDGE scan_edge_ze
    1.59 +#define SCAN_LINE scan_line_ze
    1.60 +#define INTERP_DEPTH
    1.61 +#define INTERP_ENERGY
    1.62 +#include "scantmpl.h"
    1.63 +#undef SCAN_EDGE
    1.64 +#undef SCAN_LINE
    1.65 +
    1.66 +static void (*scan_edge)(struct vertex*, struct vertex*);
    1.67 +static void (*scan_line)(int, unsigned char*);
    1.68 +
    1.69 +int mgl_rast_init(struct state *state, struct framebuffer *fbuf)
    1.70 +{
    1.71 +	fb = fbuf;
    1.72 +	st = state;
    1.73 +
    1.74 +	if(!(vleft = malloc(fb->height * sizeof *vleft))) {
    1.75 +		return -1;
    1.76 +	}
    1.77 +	if(!(vright = malloc(fb->height * sizeof *vright))) {
    1.78 +		free(vleft);
    1.79 +		return -1;
    1.80 +	}
    1.81 +
    1.82 +	scan_edge = scan_edge_flat;
    1.83 +	scan_line = scan_line_flat;
    1.84 +
    1.85 +	return 0;
    1.86 +}
    1.87 +
    1.88 +void mgl_rast_cleanup(void)
    1.89 +{
    1.90 +	free(vleft);
    1.91 +	free(vright);
    1.92 +}
    1.93 +
    1.94 +void mgl_rast_prepare(void)
    1.95 +{
    1.96 +	static void (*sedge[])(struct vertex*, struct vertex*) = {
    1.97 +		scan_edge_flat,		/* 00 */
    1.98 +		scan_edge_z,		/* 01 */
    1.99 +		scan_edge_e,		/* 10 */
   1.100 +		scan_edge_ze		/* 11 */
   1.101 +	};
   1.102 +	static void (*sline[])(int, unsigned char*) = {
   1.103 +		scan_line_flat,		/* 00 */
   1.104 +		scan_line_z,		/* 01 */
   1.105 +		scan_line_e,		/* 10 */
   1.106 +		scan_line_ze		/* 11 */
   1.107 +	};
   1.108 +	int bits = 0;
   1.109 +
   1.110 +	if(st->flags & MGL_SMOOTH) {
   1.111 +		bits |= 2;
   1.112 +	}
   1.113 +	if((st->flags & MGL_DEPTH_TEST) && fb->zbuf) {
   1.114 +		bits |= 1;
   1.115 +	}
   1.116 +
   1.117 +	scan_edge = sedge[bits];
   1.118 +	scan_line = sline[bits];
   1.119 +}
   1.120 +
   1.121 +void mgl_draw_point(struct vertex *v)
   1.122 +{
   1.123 +	int x = (int)ROUND(v->pos.x);
   1.124 +	int y = (int)ROUND(v->pos.y);
   1.125 +
   1.126 +	if(x >= 0 && x < fb->width && y >= 0 && y < fb->height) {
   1.127 +		int cidx = v->cidx + v->energy * st->col_range;
   1.128 +		fb->pixels[y * fb->width + x] = cidx;
   1.129 +	}
   1.130 +}
   1.131 +
   1.132 +void mgl_draw_line(struct vertex *v0, struct vertex *v1)
   1.133 +{
   1.134 +	/* TODO */
   1.135 +	fprintf(stderr, "draw_line unimplemented\n");
   1.136 +	abort();
   1.137 +}
   1.138 +
   1.139 +void mgl_draw_poly(struct vertex *v, int numv)
   1.140 +{
   1.141 +	int ybeg, yend, i;
   1.142 +	unsigned char *sline;
   1.143 +
   1.144 +	ybeg = fb->height;
   1.145 +	yend = 0;
   1.146 +
   1.147 +	for(i=0; i<numv; i++) {
   1.148 +		struct vertex *v0 = v + i;
   1.149 +		struct vertex *v1 = v + (i + 1) % numv;
   1.150 +		int y = (int)ROUND(v0->pos.y);
   1.151 +
   1.152 +		scan_edge(v0, v1);
   1.153 +
   1.154 +		if(y > yend) yend = y;
   1.155 +		if(y < ybeg) ybeg = y;
   1.156 +	}
   1.157 +
   1.158 +	if(ybeg < 0) ybeg = 0;
   1.159 +	if(yend >= fb->height) yend = fb->height - 1;
   1.160 +
   1.161 +	sline = fb->pixels + ybeg * fb->width;
   1.162 +	for(i=ybeg; i<yend; i++) {
   1.163 +		scan_line(i, sline);
   1.164 +		sline += fb->width;
   1.165 +	}
   1.166 +}