summaryrefslogtreecommitdiff
path: root/src/gallium/drivers/nouveau/nouveau_util.h
blob: a5e8537533e7d97e18ef5be296a3df0a41814a34 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
#ifndef __NOUVEAU_UTIL_H__
#define __NOUVEAU_UTIL_H__

/* Determine how many vertices can be pushed into the command stream.
 * Where the remaining space isn't large enough to represent all verices,
 * split the buffer at primitive boundaries.
 *
 * Returns a count of vertices that can be rendered, and an index to
 * restart drawing at after a flush.
 */
static INLINE unsigned
nouveau_vbuf_split(unsigned remaining, unsigned overhead, unsigned vpp,
		   unsigned mode, unsigned start, unsigned count,
		   unsigned *restart)
{
	int max, adj = 0;

	max  = remaining - overhead;
	if (max < 0)
		return 0;

	max *= vpp;
	if (max >= count)
		return count;

	switch (mode) {
	case PIPE_PRIM_POINTS:
		break;
	case PIPE_PRIM_LINES:
		max = max & 1;
		break;
	case PIPE_PRIM_TRIANGLES:
		max = max - (max % 3);
		break;
	case PIPE_PRIM_QUADS:
		max = max & ~3;
		break;
	case PIPE_PRIM_LINE_LOOP:
	case PIPE_PRIM_LINE_STRIP:
		if (max < 2)
			max = 0;
		adj = 1;
		break;
	case PIPE_PRIM_POLYGON:
	case PIPE_PRIM_TRIANGLE_STRIP:
	case PIPE_PRIM_TRIANGLE_FAN:
		if (max < 3)
			max = 0;
		adj = 2;
		break;
	case PIPE_PRIM_QUAD_STRIP:
		if (max < 4)
			max = 0;
		adj = 3;
		break;
	default:
		assert(0);
	}

	*restart = start + max - adj;
	return max;
}

/* Integer base-2 logarithm, rounded towards zero. */
static INLINE unsigned log2i(unsigned i)
{
	unsigned r = 0;

	if (i & 0xffff0000) {
		i >>= 16;
		r += 16;
	}
	if (i & 0x0000ff00) {
		i >>= 8;
		r += 8;
	}
	if (i & 0x000000f0) {
		i >>= 4;
		r += 4;
	}
	if (i & 0x0000000c) {
		i >>= 2;
		r += 2;
	}
	if (i & 0x00000002) {
		r += 1;
	}
	return r;
}

struct u_split_prim {
   void *priv;
   void (*emit)(void *priv, unsigned start, unsigned count);
   void (*edge)(void *priv, boolean enabled);

   unsigned mode;
   unsigned start;
   unsigned p_start;
   unsigned p_end;

   uint repeat_first:1;
   uint close_first:1;
   uint edgeflag_off:1;
};

static INLINE void
u_split_prim_init(struct u_split_prim *s,
                  unsigned mode, unsigned start, unsigned count)
{
   if (mode == PIPE_PRIM_LINE_LOOP) {
      s->mode = PIPE_PRIM_LINE_STRIP;
      s->close_first = 1;
   } else {
      s->mode = mode;
      s->close_first = 0;
   }
   s->start = start;
   s->p_start = start;
   s->p_end = start + count;
   s->edgeflag_off = 0;
   s->repeat_first = 0;
}

static INLINE boolean
u_split_prim_next(struct u_split_prim *s, unsigned max_verts)
{
   int repeat = 0;

   if (s->repeat_first) {
      s->emit(s->priv, s->start, 1);
      max_verts--;
      if (s->edgeflag_off) {
         s->edge(s->priv, TRUE);
         s->edgeflag_off = FALSE;
      }
   }

   if (s->p_start + s->close_first + max_verts >= s->p_end) {
      s->emit(s->priv, s->p_start, s->p_end - s->p_start);
      if (s->close_first)
         s->emit(s->priv, s->start, 1);
      return TRUE;
   }

   switch (s->mode) {
   case PIPE_PRIM_LINES:
      max_verts &= ~1;
      break;
   case PIPE_PRIM_LINE_STRIP:
      repeat = 1;
      break;
   case PIPE_PRIM_POLYGON:
      max_verts--;
      s->emit(s->priv, s->p_start, max_verts);
      s->edge(s->priv, FALSE);
      s->emit(s->priv, s->p_start + max_verts, 1);
      s->p_start += max_verts;
      s->repeat_first = TRUE;
      s->edgeflag_off = TRUE;
      return FALSE;
   case PIPE_PRIM_TRIANGLES:
      max_verts = max_verts - (max_verts % 3);
      break;
   case PIPE_PRIM_TRIANGLE_STRIP:
      /* to ensure winding stays correct, always split
       * on an even number of generated triangles
       */
      max_verts = max_verts & ~1;
      repeat = 2;
      break;
   case PIPE_PRIM_TRIANGLE_FAN:
      s->repeat_first = TRUE;
      repeat = 1;
      break;
   case PIPE_PRIM_QUADS:
      max_verts &= ~3;
      break;
   case PIPE_PRIM_QUAD_STRIP:
      max_verts &= ~1;
      repeat = 2;
      break;
   default:
      break;
   }

   s->emit (s->priv, s->p_start, max_verts);
   s->p_start += (max_verts - repeat);
   return FALSE;
}

#endif