1 #include <u.h>
2 #include <libc.h>
3 #include <draw.h>
4 #include <memdraw.h>
5 
6 #define poolalloc(a, b) malloc(b)
7 #define poolfree(a, b) free(b)
8 
9 void
10 memimagemove(void *from, void *to)
11 {
12 	Memdata *md;
13 
14 	md = *(Memdata**)to;
15 	if(md->base != from){
16 		print("compacted data not right: #%p\n", md->base);
17 		abort();
18 	}
19 	md->base = to;
20 
21 	/* if allocmemimage changes this must change too */
22 	md->bdata = (uchar*)&md->base[2];
23 }
24 
25 Memimage*
26 allocmemimaged(Rectangle r, u32int chan, Memdata *md, void *X)
27 {
28 	int d;
29 	u32int l;
30 	Memimage *i;
31 
32 	if(Dx(r) <= 0 || Dy(r) <= 0){
33 		werrstr("bad rectangle %R", r);
34 		return nil;
35 	}
36 	if((d = chantodepth(chan)) == 0) {
37 		werrstr("bad channel descriptor %.8lux", chan);
38 		return nil;
39 	}
40 
41 	l = wordsperline(r, d);
42 
43 	i = mallocz(sizeof(Memimage), 1);
44 	if(i == nil)
45 		return nil;
46 
47 	i->X = X;
48 	i->data = md;
49 	i->zero = sizeof(u32int)*l*r.min.y;
50 	
51 	if(r.min.x >= 0)
52 		i->zero += (r.min.x*d)/8;
53 	else
54 		i->zero -= (-r.min.x*d+7)/8;
55 	i->zero = -i->zero;
56 	i->width = l;
57 	i->r = r;
58 	i->clipr = r;
59 	i->flags = 0;
60 	i->layer = nil;
61 	i->cmap = memdefcmap;
62 	if(memsetchan(i, chan) < 0){
63 		free(i);
64 		return nil;
65 	}
66 	return i;
67 }
68 
69 Memimage*
70 _allocmemimage(Rectangle r, u32int chan)
71 {
72 	int d;
73 	u32int l, nw;
74 	Memdata *md;
75 	Memimage *i;
76 
77 	if((d = chantodepth(chan)) == 0) {
78 		werrstr("bad channel descriptor %.8lux", chan);
79 		return nil;
80 	}
81 
82 	l = wordsperline(r, d);
83 	nw = l*Dy(r);
84 	md = malloc(sizeof(Memdata));
85 	if(md == nil)
86 		return nil;
87 
88 	md->ref = 1;
89 	/*
90 	 * The first two words are the md and the callerpc.
91 	 * Then nw words of data.
92 	 * The final word lets the drawing routines be a little
93 	 * sloppy about reading past the end of the block.
94 	 */
95 	md->base = poolalloc(imagmem, (2+nw+1)*sizeof(u32int));
96 	if(md->base == nil){
97 		free(md);
98 		return nil;
99 	}
100 
101 	md->base[0] = (u32int)md;
102 	md->base[1] = getcallerpc(&r);
103 
104 	/* if this changes, memimagemove must change too */
105 	md->bdata = (uchar*)&md->base[2];
106 
107 	md->allocd = 1;
108 
109 	i = allocmemimaged(r, chan, md, nil);
110 	if(i == nil){
111 		poolfree(imagmem, md->base);
112 		free(md);
113 		return nil;
114 	}
115 	md->imref = i;
116 	return i;
117 }
118 
119 void
120 _freememimage(Memimage *i)
121 {
122 	if(i == nil)
123 		return;
124 	if(i->data->ref-- == 1 && i->data->allocd){
125 		if(i->data->base)
126 			poolfree(imagmem, i->data->base);
127 		free(i->data);
128 	}
129 	free(i);
130 }
131 
132 /*
133  * Wordaddr is deprecated.
134  */
135 u32int*
136 wordaddr(Memimage *i, Point p)
137 {
138 	return (u32int*) ((u32int)byteaddr(i, p) & ~(sizeof(u32int)-1));
139 }
140 
141 uchar*
142 byteaddr(Memimage *i, Point p)
143 {
144 	uchar *a;
145 
146 	a = i->data->bdata+i->zero+sizeof(u32int)*p.y*i->width;
147 
148 	if(i->depth < 8){
149 		/*
150 		 * We need to always round down,
151 		 * but C rounds toward zero.
152 		 */
153 		int np;
154 		np = 8/i->depth;
155 		if(p.x < 0)
156 			return a+(p.x-np+1)/np;
157 		else
158 			return a+p.x/np;
159 	}
160 	else
161 		return a+p.x*(i->depth/8);
162 }
163 
164 int
165 memsetchan(Memimage *i, u32int chan)
166 {
167 	int d;
168 	int t, j, k;
169 	u32int cc;
170 	int bytes;
171 
172 	if((d = chantodepth(chan)) == 0) {
173 		werrstr("bad channel descriptor");
174 		return -1;
175 	}
176 
177 	i->depth = d;
178 	i->chan = chan;
179 	i->flags &= ~(Fgrey|Falpha|Fcmap|Fbytes);
180 	bytes = 1;
181 	for(cc=chan, j=0, k=0; cc; j+=NBITS(cc), cc>>=8, k++){
182 		t=TYPE(cc);
183 		if(t < 0 || t >= NChan){
184 			werrstr("bad channel string");
185 			return -1;
186 		}
187 		if(t == CGrey)
188 			i->flags |= Fgrey;
189 		if(t == CAlpha)
190 			i->flags |= Falpha;
191 		if(t == CMap && i->cmap == nil){
192 			i->cmap = memdefcmap;
193 			i->flags |= Fcmap;
194 		}
195 
196 		i->shift[t] = j;
197 		i->mask[t] = (1<<NBITS(cc))-1;
198 		i->nbits[t] = NBITS(cc);
199 		if(NBITS(cc) != 8)
200 			bytes = 0;
201 	}
202 	i->nchan = k;
203 	if(bytes)
204 		i->flags |= Fbytes;
205 	return 0;
206 }