X-Git-Url: https://jasonwoof.com/gitweb/?p=vor.git;a=blobdiff_plain;f=shape.c;h=75424ef9ed104e9468e7306e21a0df264b113dba;hp=9d0501c24485ae6539af2c340b2daf1efee38fc6;hb=2b5dd5bc0eb1739dd744de6f565d0f3a7ae02c95;hpb=8193e09e49bc571f9c61e6e3adf45010271c08d5

diff --git a/shape.c b/shape.c
index 9d0501c..75424ef 100644
--- a/shape.c
+++ b/shape.c
@@ -1,4 +1,5 @@
 #include <stdlib.h>
+#include "common.h"
 #include "shape.h"
 
 void
@@ -6,16 +7,17 @@ get_shape(SDL_Surface *img, struct shape *s)
 {
 	int x, y;
 	uint16_t *px, transp;
-	uint32_t bits;
+	uint32_t bits, bit, *p;
 
 	if(img->format->BytesPerPixel != 2) {
 		fprintf(stderr, "get_shape(): not a 16-bit image!\n");
 		exit(1);
 	}
 
+	s->area = 0;
 	s->w = img->w; s->h = img->h;
-	s->mw = ((img->w+31)>>5) * img->h;
-	s->mask = malloc(4*s->mw);
+	s->mw = ((img->w+31)>>5);
+	s->mask = malloc(4*s->mw*s->h);
 	if(!s->mask) {
 		fprintf(stderr, "can't malloc bitmask");
 		exit(1);
@@ -24,27 +26,73 @@ get_shape(SDL_Surface *img, struct shape *s)
 	SDL_LockSurface(img);
 	px = img->pixels;
 	transp = img->format->colorkey;
-	bits = 0;
+	p = s->mask;
 	for(y=0; y<img->h; y++) {
+		bit = 0;
 		for(x=0; x<img->w; x++) {
-			if(*px++ != transp) bits |= 1;
-			if(x == img->w-1 || !(x+1)%32) {
-				*(s->mask++) = bits;
-				bits = 0;
-			} else bits = bits << 1;
+			if(!bit) { bits = 0; bit = 0x80000000; }
+			if(*px++ != transp) { bits |= bit; s->area++; }
+			bit >>= 1;
+			if(!bit || x == img->w - 1) { *(p++) = bits; }
 		}
 		px = (uint16_t *) ((uint8_t *) px + img->pitch - 2*img->w);
 	}
 	SDL_UnlockSurface(img);
 }
 
-#ifndef max
-#define max(a, b) ((a) > (b) ? (a) : (b))
-#endif
+int
+line_collide(int xov, struct shape *r, uint32_t *rbits, struct shape *s, uint32_t *sbits)
+{
+	int lshift, n, i, ret = 0;
+	uint32_t lbits;
+	struct shape *st;
+	uint32_t *bt;
+
+
+	if(xov < 0) {
+		st = r; r = s; s = st;
+		bt = rbits; rbits = sbits; sbits = bt;
+		xov = -xov;
+	}
+
+
+	lshift = (r->w - xov) & 31; 
+	rbits += (r->w - xov) >> 5;
+	n = (xov + 31) >> 5;
+	for(i=0; i<n-1; i++) {
+		lbits = *rbits++ << lshift;
+		lbits |= *rbits >> (32 - lshift);
+		if(lbits & *sbits++) ret = 1;
+	}
+	lbits = *rbits << lshift;
+	if(lbits & *sbits) ret = 1;
+
+	return ret;
+}
+
+int
+mask_collide(int xov, int yov, struct shape *r, struct shape *s)
+{
+	int y, ry, sy;
+	uint32_t *rbits, *sbits;
+
+	if(yov > 0) {
+		ry = r->h - yov; sy = 0;
+		rbits = r->mask + (r->h - yov) * r->mw;
+		sbits = s->mask;
+	} else {
+		ry = 0; sy = s->h + yov;
+		rbits = r->mask;
+		sbits = s->mask + (s->h + yov) * s->mw;
+	}
 
-#ifndef min
-#define min(a, b) ((a) < (b) ? (a) : (b))
-#endif
+	for(y=0; y<abs(yov); y++) {
+		if(line_collide(xov, r, rbits, s, sbits)) return 1;
+		rbits += r->mw; sbits += s->mw;
+	}
+
+	return 0;
+}
 
 int
 collide(int xdiff, int ydiff, struct shape *r, struct shape *s)
@@ -52,12 +100,22 @@ collide(int xdiff, int ydiff, struct shape *r, struct shape *s)
 	int xov, yov;
 
 	if(xdiff >= 0) xov = max(min(r->w-xdiff, s->w), 0);
-	else xov = -max(min(s->w+xdiff, r->w), 0);
+	else xov = min(-min(s->w+xdiff, r->w), 0);
 
 	if(ydiff >= 0) yov = max(min(r->h-ydiff, s->h), 0);
-	else yov = -max(min(s->h+ydiff, r->h), 0);
+	else yov = min(-min(s->h+ydiff, r->h), 0);
 
-	if(xov == 0 && yov == 0) return 0;
+	if(xov == 0 || yov == 0) return 0;  // bboxes hit?
+	else return mask_collide(xov, yov, r, s);
+}
 
-	return 0;
+int
+pixel_collide(unsigned int xoff, unsigned int yoff, struct shape *r)
+{
+	uint32_t pmask;
+	
+	if(xoff >= r->w || yoff >= r->h) return 0;
+
+	pmask = 0x80000000 >> (xoff&0x1f);
+	return r->mask[(yoff*r->mw) + (xoff>>5)] & pmask;
 }