tf.c
8.14 KB
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
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
/**************************************************************************
* *
* Copyright (C) 1994, Silicon Graphics, Inc. *
* *
* These coded instructions, statements, and computer programs contain *
* unpublished proprietary information of Silicon Graphics, Inc., and *
* are protected by Federal copyright law. They may not be disclosed *
* to third parties or copied or duplicated in any form, in whole or *
* in part, without the prior written consent of Silicon Graphics, Inc. *
* *
**************************************************************************/
/*
* Texture Filter Unit
*
* This unit implements a bi-planar interpolator for filtering texture
* maps, and can also be used to implement part of the color conversion
* YUV->RGB equation. Feedback is provided so that a YUV texture can be
* filtered and then color converted and the subsequent clock.
*
* NOTE: incoming pixels are either RGBA or UVYY.
* texture interpolation is triangular:
* tf = (txh - txt)*sfrac + (txv - txt)*tfrac + txt
* when mid_texel mode bit is set and at center of pixel:
* tf = (txh + txv + txt + txo) / 4
* when doing YUV->RGB conversion:
* r' = y + k0*v
* g' = y + k1*u + k2*v
* b' = y + k3*u
*/
#include <stdio.h>
#include "tf.h"
#define SIGN_EXTEND_9B(x) ((x & 0x100) ? ((x) | ~0x1ff) : (x))
#define POSEDGE (save_clk && !save_clk_old)
#define NEGEDGE (!save_clk && save_clk_old)
/***************************************************************************
* triangular_interp() - return s,8.0 number
*
***************************************************************************/
int
triangular_interp(int suba_a, int suba_b, int mula, int subb_a,
int subb_b, int mulb, int startp, int offa, int offb)
{
int suba_out, subb_out, mula_out, mulb_out, result;
int mul_comb;
suba_a = SIGN_EXTEND_9B(suba_a);
suba_b = SIGN_EXTEND_9B(suba_b);
mula = SIGN_EXTEND_9B(mula);
subb_a = SIGN_EXTEND_9B(subb_a);
subb_b = SIGN_EXTEND_9B(subb_b);
mulb = SIGN_EXTEND_9B(mulb);
startp = SIGN_EXTEND_9B(startp);
offa = SIGN_EXTEND_9B(offa);
offb = SIGN_EXTEND_9B(offb);
/* fprintf(stderr," %08x %08x %08x %08x %08x %08x %08x %08x %08x\n", suba_a, suba_b, mula, subb_a, subb_b, mulb, startp, offa, offb); */
suba_out = suba_a - suba_b;
subb_out = subb_a - subb_b;
mula_out = mula * suba_out; /* Full Precision */
mulb_out = mulb * subb_out; /* Full Precision */
mul_comb = (mula_out + mulb_out) >> 6;
/* note, + 2 is for rounding */
result = (mul_comb + (startp << 2) + offa + (offb+1) + 2) >> 2;
/* fprintf(stderr,"%08x %08x %08x %08x %08x\n", suba_out, subb_out, mula_out, mulb_out, result); */
return(result & 0x1ff);
}
/***************************************************************************
* tf() - interface to texture filter
*
***************************************************************************/
void
tf(tf_t **pp0, tf_t **pp1)
{
/* pointer to memory structures */
tf_t *p0, *p1;
int save_clk;
int save_clk_old;
/* temporary signals */
int bilerp, loop_back;
int suba_a, suba_b;
int subb_a, subb_b;
int mula, mulb;
int startp, offa, offb;
int suba_out, mula_out, subb_out, mulb_out;
int shift_r, shift_l;
int interp, sl, sr;
int pcr, far, fbr, pcg, pcb, fab, fbb, pca;
int mid_uv, mid_y;
/* get started */
p0 = *pp0;
p1 = *pp1;
save_clk = p0->gclk;
save_clk_old = p1->gclk_old;
if(POSEDGE)
{
/* transfer all next-clock register values to register outputs. */
*pp0 = p1; /* swap */
*pp1 = p0;
p0 = *pp0; /* fix pointers */
p1 = *pp1;
/* Update all next-clock register values */
/* delay lod fraction */
p0->lod_frac_d1 = p1->lod_frac;
p0->tf_lod_frac = p1->lod_frac_d1;
/* delay lod_greater_than_1 */
p0->lge1_d1 = p1->lge1;
p0->tf_lge1 = p1->lge1_d1;
/* generate cycle */
if(p1->st_span || !p1->ncyc)
p0->cycle = 0;
else
p0->cycle = ~p1->cycle;
/* ************************************************
ORDER DEPENDENT SECTION
* ************************************************/
/* determine mux selects */
bilerp = (p1->cycle) ? p1->bilerp1m : p1->bilerp0m;
/* L o o p B a c k M u x */
loop_back = p1->convert_one && p1->cycle;
p0->loop_d1 = loop_back;
pcr = p1->loop_d1 ? p1->tf_b : p1->txtrb_d1;
far = p1->loop_d1 ? p1->tf_r : p1->txtr_sfuv_d1;
fbr = p1->loop_d1 ? p1->tf_g : p1->txtg_tfuv_d1;
pcg = p1->loop_d1 ? p1->tf_b : p1->txtgb_d1;
pcb = p1->loop_d1 ? p1->tf_b : p1->txtb_d1;
fab = p1->loop_d1 ? p1->tf_r : p1->txtr_sfy_d1;
fbb = p1->loop_d1 ? p1->tf_g : p1->txtg_tfy_d1;
pca = p1->loop_d1 ? p1->tf_b : p1->txta_d1;
/* M i d UV / Y */
mid_uv = bilerp && p1->mid_texel &&
(p1->sfrac_rg & 0xf8) == 0x80 && (p1->tfrac_rg & 0xf8) == 0x80;
mid_y = bilerp && p1->mid_texel &&
(p1->sfrac_ba & 0xf8) == 0x80 && (p1->tfrac_ba & 0xf8) == 0x80;
/* R E D C o m p o n e n t */
p0->txtrb_d1 = bilerp ? p1->tm_ra : p1->tm_ba;
p0->xar = bilerp ? p1->tm_rb : 0;
p0->yar = bilerp ? p1->tm_ra : 0;
p0->xbr = bilerp ? p1->tm_rc : p1->k0_coeff;
p0->ybr = bilerp ? p1->tm_ra : ~SIGN_EXTEND_9B(p1->k0_coeff);
p0->txtr_sfuv_d1 = bilerp ? (mid_uv ? (p1->sfrac_rg >> 1) : p1->sfrac_rg) : p1->tm_ra;
p0->txtg_tfuv_d1 = bilerp ? (mid_uv ? (p1->tfrac_rg >> 1) : p1->tfrac_rg) : p1->tm_ga;
p0->por = mid_uv ? p1->tm_rd : 0;
p0->ptr = ~( mid_uv ? SIGN_EXTEND_9B(p1->tm_ra) : 0x0 );
/* do the math */
p0->tf_r = triangular_interp(p1->xar, p1->yar, far, p1->xbr, p1->ybr, fbr,
pcr, p1->por, p1->ptr);
/* G R E E N C o m p o n e n t */
p0->txtgb_d1 = bilerp ? p1->tm_ga : p1->tm_ba;
p0->xag = bilerp ? p1->tm_gb : p1->k1_coeff;
p0->yag = bilerp ? p1->tm_ga : ~SIGN_EXTEND_9B(p1->k1_coeff);
p0->xbg = bilerp ? p1->tm_gc : p1->k2_coeff;
p0->ybg = bilerp ? p1->tm_ga : ~SIGN_EXTEND_9B(p1->k2_coeff);
p0->pog = mid_uv ? p1->tm_gd : 0;
p0->ptg = ~(mid_uv ? SIGN_EXTEND_9B(p1->tm_ga) : 0);
/* do the math */
p0->tf_g = triangular_interp(p1->xag, p1->yag, far, p1->xbg, p1->ybg, fbr,
pcg, p1->pog, p1->ptg);
/* B L U E C o m p o n e n t */
p0->txtb_d1 = p1->tm_ba;
p0->xab = bilerp ? p1->tm_bb : p1->k3_coeff;
p0->yab = bilerp ? p1->tm_ba : ~SIGN_EXTEND_9B(p1->k3_coeff);
p0->xbb = bilerp ? p1->tm_bc : 0;
p0->ybb = bilerp ? p1->tm_ba : 0;
p0->txtr_sfy_d1 = bilerp ? (mid_y ? (p1->sfrac_ba >> 1) : p1->sfrac_ba) : p1->tm_ra;
p0->txtg_tfy_d1 = bilerp ? (mid_y ? (p1->tfrac_ba >> 1) : p1->tfrac_ba) : p1->tm_ga;
p0->pob = mid_y ? p1->tm_bd : 0;
p0->ptb = ~( mid_y ? SIGN_EXTEND_9B(p1->tm_ba) : 0x0);
/* do the math */
p0->tf_b = triangular_interp(p1->xab, p1->yab, fab, p1->xbb, p1->ybb, fbb,
pcb, p1->pob, p1->ptb);
/* A L P H A C o m p o n e n t */
p0->txta_d1 = bilerp ? p1->tm_aa : p1->tm_ba;
p0->xaa = bilerp ? p1->tm_ab : 0;
p0->yaa = bilerp ? p1->tm_aa : 0;
p0->xba = bilerp ? p1->tm_ac : 0;
p0->yba = bilerp ? p1->tm_aa : 0;
p0->poa = mid_y ? p1->tm_ad : 0;
p0->pta = ~(mid_y ? SIGN_EXTEND_9B(p1->tm_aa) : 0x0);
/* do the math */
p0->tf_a = triangular_interp(p1->xaa, p1->yaa, fab, p1->xba, p1->yba, fbb,
pca, p1->poa, p1->pta);
/* ************************************************
END OF ORDER DEPENDENT SECTION
* ************************************************/
} /* posedge */
p0->gclk_old = p1->gclk_old = save_clk;
}
/***************************************************************************
* tf_init() - init texture filter
***************************************************************************/
void
tf_init(tf_t *p0, tf_t *p1)
{
p1->cycle = p0->cycle = 0;
p1->gclk = p0->gclk = 0;
p1->gclk_old = p0->gclk_old = 0;
}