X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=dosdemo;a=blobdiff_plain;f=src%2Fpolyclip.c;fp=src%2Fpolyclip.c;h=0000000000000000000000000000000000000000;hp=35e6cd62a0fedf07263adcfc8fadae41b14ec1d7;hb=57bd2dc519c47f434e3e5acf998fb9c72448cbce;hpb=d956a9d9273eebfacfda58cb3bafff017269d5dc

diff --git a/src/polyclip.c b/src/polyclip.c
deleted file mode 100644
index 35e6cd6..0000000
--- a/src/polyclip.c
+++ /dev/null
@@ -1,331 +0,0 @@
-#include <stdio.h>
-#include <math.h>
-#include <assert.h>
-#include "polyclip.h"
-
-struct ray {
-	float origin[3];
-	float dir[3];
-};
-
-static int clip_edge(struct g3d_vertex *poly, int *vnumptr,
-		const struct g3d_vertex *v0, const struct g3d_vertex *v1,
-		const struct cplane *plane);
-static int check_clip_edge(const struct g3d_vertex *v0,
-		const struct g3d_vertex *v1, const struct cplane *plane);
-static int clip_edge_frustum(struct g3d_vertex *poly, int *vnumptr,
-		const struct g3d_vertex *v0, const struct g3d_vertex *v1, int fplane);
-static float distance_signed(float *pos, const struct cplane *plane);
-static int intersect(const struct ray *ray, const struct cplane *plane, float *t);
-static int inside_frustum_plane(const struct g3d_vertex *v, int fplane);
-
-
-int clip_poly(struct g3d_vertex *vout, int *voutnum,
-		const struct g3d_vertex *vin, int vnum, struct cplane *plane)
-{
-	int i, nextidx, res;
-	int edges_clipped = 0;
-
-	*voutnum = 0;
-
-	for(i=0; i<vnum; i++) {
-		nextidx = i + 1;
-		if(nextidx >= vnum) nextidx = 0;
-		res = clip_edge(vout, voutnum, vin + i, vin + nextidx, plane);
-		if(res == 0) {
-			++edges_clipped;
-		}
-	}
-
-	if(*voutnum <= 0) {
-		assert(edges_clipped == 0);
-		return -1;
-	}
-
-	return edges_clipped > 0 ? 0 : 1;
-}
-
-int check_clip_poly(const struct g3d_vertex *v, int vnum, struct cplane *plane)
-{
-	int i, nextidx, res;
-	int edges_clipped = 0;
-
-	for(i=0; i<vnum; i++) {
-		nextidx = i + 1;
-		if(nextidx >= vnum) nextidx = 0;
-		res = check_clip_edge(v + i, v + nextidx, plane);
-		if(res == 0) {
-			++edges_clipped;
-		}
-	}
-	return edges_clipped ? 0 : res;
-}
-
-int clip_frustum(struct g3d_vertex *vout, int *voutnum,
-		const struct g3d_vertex *vin, int vnum, int fplane)
-{
-	int i, nextidx, res;
-	int edges_clipped = 0;
-
-	if(vnum == 1) {
-		/* special case: point clipping */
-		return inside_frustum_plane(vin, fplane) ? 1 : -1;
-	}
-
-	*voutnum = 0;
-
-	for(i=0; i<vnum; i++) {
-		nextidx = i + 1;
-		if(nextidx >= vnum) nextidx = 0;
-		res = clip_edge_frustum(vout, voutnum, vin + i, vin + nextidx, fplane);
-		if(res == 0) {
-			++edges_clipped;
-		}
-	}
-
-	if(*voutnum <= 0) {
-		assert(edges_clipped == 0);
-		return -1;
-	}
-
-	return edges_clipped > 0 ? 0 : 1;
-}
-
-#define LERP_VATTR(res, v0, v1, t) \
-	do { \
-		(res)->nx = (v0)->nx + ((v1)->nx - (v0)->nx) * (t); \
-		(res)->ny = (v0)->ny + ((v1)->ny - (v0)->ny) * (t); \
-		(res)->nz = (v0)->nz + ((v1)->nz - (v0)->nz) * (t); \
-		(res)->u = (v0)->u + ((v1)->u - (v0)->u) * (t); \
-		(res)->v = (v0)->v + ((v1)->v - (v0)->v) * (t); \
-		(res)->r = (v0)->r + ((v1)->r - (v0)->r) * (t); \
-		(res)->g = (v0)->g + ((v1)->g - (v0)->g) * (t); \
-		(res)->b = (v0)->b + ((v1)->b - (v0)->b) * (t); \
-	} while(0)
-
-
-/* returns:
- *  1 -> both inside
- *  0 -> straddling and clipped
- * -1 -> both outside
- *
- *  also returns the size of the polygon through vnumptr
- */
-static int clip_edge(struct g3d_vertex *poly, int *vnumptr,
-		const struct g3d_vertex *v0, const struct g3d_vertex *v1,
-		const struct cplane *plane)
-{
-	float pos0[3], pos1[3];
-	float d0, d1, t;
-	struct ray ray;
-	int i, vnum = *vnumptr;
-
-	pos0[0] = v0->x; pos0[1] = v0->y; pos0[2] = v0->z;
-	pos1[0] = v1->x; pos1[1] = v1->y; pos1[2] = v1->z;
-
-	d0 = distance_signed(pos0, plane);
-	d1 = distance_signed(pos1, plane);
-
-	for(i=0; i<3; i++) {
-		ray.origin[i] = pos0[i];
-		ray.dir[i] = pos1[i] - pos0[i];
-	}
-
-	if(d0 >= 0.0) {
-		/* start inside */
-		if(d1 >= 0.0) {
-			/* all inside */
-			poly[vnum++] = *v1;	/* append v1 */
-			*vnumptr = vnum;
-			return 1;
-		} else {
-			/* going out */
-			struct g3d_vertex *vptr = poly + vnum;
-
-			intersect(&ray, plane, &t);
-
-			vptr->x = ray.origin[0] + ray.dir[0] * t;
-			vptr->y = ray.origin[1] + ray.dir[1] * t;
-			vptr->z = ray.origin[2] + ray.dir[2] * t;
-			vptr->w = 1.0f;
-
-			LERP_VATTR(vptr, v0, v1, t);
-			vnum++;	/* append new vertex on the intersection point */
-		}
-	} else {
-		/* start outside */
-		if(d1 >= 0) {
-			/* going in */
-			struct g3d_vertex *vptr = poly + vnum;
-
-			intersect(&ray, plane, &t);
-
-			vptr->x = ray.origin[0] + ray.dir[0] * t;
-			vptr->y = ray.origin[1] + ray.dir[1] * t;
-			vptr->z = ray.origin[2] + ray.dir[2] * t;
-			vptr->w = 1.0f;
-
-			LERP_VATTR(vptr, v0, v1, t);
-			vnum++;	/* append new vertex on the intersection point */
-
-			/* then append v1 ... */
-			poly[vnum++] = *v1;
-		} else {
-			/* all outside */
-			return -1;
-		}
-	}
-
-	*vnumptr = vnum;
-	return 0;
-}
-
-/* same as above, but only checks for clipping and classifies the edge */
-static int check_clip_edge(const struct g3d_vertex *v0,
-		const struct g3d_vertex *v1, const struct cplane *plane)
-{
-	float pos0[3], pos1[3];
-	float d0, d1;
-
-	pos0[0] = v0->x; pos0[1] = v0->y; pos0[2] = v0->z;
-	pos1[0] = v1->x; pos1[1] = v1->y; pos1[2] = v1->z;
-
-	d0 = distance_signed(pos0, plane);
-	d1 = distance_signed(pos1, plane);
-
-	if(d0 > 0.0f && d1 > 0.0f) {
-		return 1;
-	}
-	if(d0 < 0.0f && d1 < 0.0f) {
-		return -1;
-	}
-	return 0;
-}
-
-static float distance_signed(float *pos, const struct cplane *plane)
-{
-	float dx = pos[0] - plane->x;
-	float dy = pos[1] - plane->y;
-	float dz = pos[2] - plane->z;
-	return dx * plane->nx + dy * plane->ny + dz * plane->nz;
-}
-
-static int intersect(const struct ray *ray, const struct cplane *plane, float *t)
-{
-	float orig_pt_dir[3];
-
-	float ndotdir = plane->nx * ray->dir[0] + plane->ny * ray->dir[1] + plane->nz * ray->dir[2];
-	if(fabs(ndotdir) < 1e-6) {
-		*t = 0.0f;
-		return 0;
-	}
-
-	orig_pt_dir[0] = plane->x - ray->origin[0];
-	orig_pt_dir[1] = plane->y - ray->origin[1];
-	orig_pt_dir[2] = plane->z - ray->origin[2];
-
-	*t = (plane->nx * orig_pt_dir[0] + plane->ny * orig_pt_dir[1] + plane->nz * orig_pt_dir[2]) / ndotdir;
-	return 1;
-}
-
-/* homogeneous frustum clipper helpers */
-
-static int inside_frustum_plane(const struct g3d_vertex *v, int fplane)
-{
-	switch(fplane) {
-	case CLIP_LEFT:
-		return v->x >= -v->w;
-	case CLIP_RIGHT:
-		return v->x <= v->w;
-	case CLIP_BOTTOM:
-		return v->y >= -v->w;
-	case CLIP_TOP:
-		return v->y <= v->w;
-	case CLIP_NEAR:
-		return v->z >= -v->w;
-	case CLIP_FAR:
-		return v->z <= v->w;
-	}
-	assert(0);
-	return 0;
-}
-
-static float intersect_frustum(const struct g3d_vertex *a, const struct g3d_vertex *b, int fplane)
-{
-	switch(fplane) {
-	case CLIP_LEFT:
-		return (-a->w - a->x) / (b->x - a->x + b->w - a->w);
-	case CLIP_RIGHT:
-		return (a->w - a->x) / (b->x - a->x - b->w + a->w);
-	case CLIP_BOTTOM:
-		return (-a->w - a->y) / (b->y - a->y + b->w - a->w);
-	case CLIP_TOP:
-		return (a->w - a->y) / (b->y - a->y - b->w + a->w);
-	case CLIP_NEAR:
-		return (-a->w - a->z) / (b->z - a->z + b->w - a->w);
-	case CLIP_FAR:
-		return (a->w - a->z) / (b->z - a->z - b->w + a->w);
-	}
-
-	assert(0);
-	return 0;
-}
-
-static int clip_edge_frustum(struct g3d_vertex *poly, int *vnumptr,
-		const struct g3d_vertex *v0, const struct g3d_vertex *v1, int fplane)
-{
-	int vnum = *vnumptr;
-	int in0, in1;
-	float t;
-
-	in0 = inside_frustum_plane(v0, fplane);
-	in1 = inside_frustum_plane(v1, fplane);
-
-	if(in0) {
-		/* start inside */
-		if(in1) {
-			/* all inside */
-			poly[vnum++] = *v1;	/* append v1 */
-			*vnumptr = vnum;
-			return 1;
-		} else {
-			/* going out */
-			struct g3d_vertex *vptr = poly + vnum;
-
-			t = intersect_frustum(v0, v1, fplane);
-
-			vptr->x = v0->x + (v1->x - v0->x) * t;
-			vptr->y = v0->y + (v1->y - v0->y) * t;
-			vptr->z = v0->z + (v1->z - v0->z) * t;
-			vptr->w = v0->w + (v1->w - v0->w) * t;
-
-			LERP_VATTR(vptr, v0, v1, t);
-			++vnum;	/* append new vertex on the intersection point */
-		}
-	} else {
-		/* start outside */
-		if(in1) {
-			/* going in */
-			struct g3d_vertex *vptr = poly + vnum;
-
-			t = intersect_frustum(v0, v1, fplane);
-
-			vptr->x = v0->x + (v1->x - v0->x) * t;
-			vptr->y = v0->y + (v1->y - v0->y) * t;
-			vptr->z = v0->z + (v1->z - v0->z) * t;
-			vptr->w = v0->w + (v1->w - v0->w) * t;
-
-			LERP_VATTR(vptr, v0, v1, t);
-			++vnum;	/* append new vertex on the intersection point */
-
-			/* then append v1 ... */
-			poly[vnum++] = *v1;
-		} else {
-			/* all outside */
-			return -1;
-		}
-	}
-
-	*vnumptr = vnum;
-	return 0;
-}