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1 /* libs/pixelflinger/buffer.cpp
2 **
3 ** Copyright 2006, The Android Open Source Project
4 **
5 ** Licensed under the Apache License, Version 2.0 (the "License");
6 ** you may not use this file except in compliance with the License.
7 ** You may obtain a copy of the License at
8 **
9 **     http://www.apache.org/licenses/LICENSE-2.0
10 **
11 ** Unless required by applicable law or agreed to in writing, software
12 ** distributed under the License is distributed on an "AS IS" BASIS,
13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 ** See the License for the specific language governing permissions and
15 ** limitations under the License.
16 */
17 
18 
19 #include <assert.h>
20 
21 #include "buffer.h"
22 
23 namespace android {
24 // ----------------------------------------------------------------------------
25 
26 static void read_pixel(const surface_t* s, context_t* c,
27         uint32_t x, uint32_t y, pixel_t* pixel);
28 static void write_pixel(const surface_t* s, context_t* c,
29         uint32_t x, uint32_t y, const pixel_t* pixel);
30 static void readRGB565(const surface_t* s, context_t* c,
31         uint32_t x, uint32_t y, pixel_t* pixel);
32 static void readABGR8888(const surface_t* s, context_t* c,
33         uint32_t x, uint32_t y, pixel_t* pixel);
34 
35 static uint32_t logic_op(int op, uint32_t s, uint32_t d);
36 static uint32_t extract(uint32_t v, int h, int l, int bits);
37 static uint32_t expand(uint32_t v, int sbits, int dbits);
38 static uint32_t downshift_component(uint32_t in, uint32_t v,
39         int sh, int sl, int dh, int dl, int ch, int cl, int dither);
40 
41 // ----------------------------------------------------------------------------
42 
ggl_init_texture(context_t * c)43 void ggl_init_texture(context_t* c)
44 {
45     for (int i=0 ; i<GGL_TEXTURE_UNIT_COUNT ; i++) {
46         texture_t& t = c->state.texture[i];
47         t.s_coord = GGL_ONE_TO_ONE;
48         t.t_coord = GGL_ONE_TO_ONE;
49         t.s_wrap = GGL_REPEAT;
50         t.t_wrap = GGL_REPEAT;
51         t.min_filter = GGL_NEAREST;
52         t.mag_filter = GGL_NEAREST;
53         t.env = GGL_MODULATE;
54     }
55     c->activeTMU = &(c->state.texture[0]);
56 }
57 
ggl_set_surface(context_t * c,surface_t * dst,const GGLSurface * src)58 void ggl_set_surface(context_t* c, surface_t* dst, const GGLSurface* src)
59 {
60     dst->width = src->width;
61     dst->height = src->height;
62     dst->stride = src->stride;
63     dst->data = src->data;
64     dst->format = src->format;
65     dst->dirty = 1;
66     if (__builtin_expect(dst->stride < 0, false)) {
67         const GGLFormat& pixelFormat(c->formats[dst->format]);
68         const int32_t bpr = -dst->stride * pixelFormat.size;
69         dst->data += bpr * (dst->height-1);
70     }
71 }
72 
pick_read_write(surface_t * s)73 static void pick_read_write(surface_t* s)
74 {
75     // Choose best reader/writers.
76     switch (s->format) {
77         case GGL_PIXEL_FORMAT_RGBA_8888:    s->read = readABGR8888;  break;
78         case GGL_PIXEL_FORMAT_RGB_565:      s->read = readRGB565;    break;
79         default:                            s->read = read_pixel;    break;
80     }
81     s->write = write_pixel;
82 }
83 
ggl_pick_texture(context_t * c)84 void ggl_pick_texture(context_t* c)
85 {
86     for (int i=0 ; i<GGL_TEXTURE_UNIT_COUNT ; ++i) {
87         surface_t& s = c->state.texture[i].surface;
88         if ((!c->state.texture[i].enable) || (!s.dirty))
89             continue;
90         s.dirty = 0;
91         pick_read_write(&s);
92         generated_tex_vars_t& gen = c->generated_vars.texture[i];
93         gen.width   = s.width;
94         gen.height  = s.height;
95         gen.stride  = s.stride;
96         gen.data    = int32_t(s.data);
97     }
98 }
99 
ggl_pick_cb(context_t * c)100 void ggl_pick_cb(context_t* c)
101 {
102     surface_t& s = c->state.buffers.color;
103     if (s.dirty) {
104         s.dirty = 0;
105         pick_read_write(&s);
106     }
107 }
108 
109 // ----------------------------------------------------------------------------
110 
read_pixel(const surface_t * s,context_t * c,uint32_t x,uint32_t y,pixel_t * pixel)111 void read_pixel(const surface_t* s, context_t* c,
112         uint32_t x, uint32_t y, pixel_t* pixel)
113 {
114     assert((x < s->width) && (y < s->height));
115 
116     const GGLFormat* f = &(c->formats[s->format]);
117     int32_t index = x + (s->stride * y);
118     uint8_t* const data = s->data + index * f->size;
119     uint32_t v = 0;
120     switch (f->size) {
121         case 1:		v = *data;									break;
122         case 2:		v = *(uint16_t*)data;						break;
123         case 3:		v = (data[2]<<16)|(data[1]<<8)|data[0];     break;
124         case 4:		v = GGL_RGBA_TO_HOST(*(uint32_t*)data);		break;
125     }
126     for (int i=0 ; i<4 ; i++) {
127         pixel->s[i] = f->c[i].h - f->c[i].l;
128         if (pixel->s[i])
129             pixel->c[i] = extract(v,  f->c[i].h,  f->c[i].l, f->size*8);
130     }
131 }
132 
readRGB565(const surface_t * s,context_t * c,uint32_t x,uint32_t y,pixel_t * pixel)133 void readRGB565(const surface_t* s, context_t* c,
134         uint32_t x, uint32_t y, pixel_t* pixel)
135 {
136     uint16_t v = *(reinterpret_cast<uint16_t*>(s->data) + (x + (s->stride * y)));
137     pixel->c[0] = 0;
138     pixel->c[1] = v>>11;
139     pixel->c[2] = (v>>5)&0x3F;
140     pixel->c[3] = v&0x1F;
141     pixel->s[0] = 0;
142     pixel->s[1] = 5;
143     pixel->s[2] = 6;
144     pixel->s[3] = 5;
145 }
146 
readABGR8888(const surface_t * s,context_t * c,uint32_t x,uint32_t y,pixel_t * pixel)147 void readABGR8888(const surface_t* s, context_t* c,
148         uint32_t x, uint32_t y, pixel_t* pixel)
149 {
150     uint32_t v = *(reinterpret_cast<uint32_t*>(s->data) + (x + (s->stride * y)));
151     v = GGL_RGBA_TO_HOST(v);
152     pixel->c[0] = v>>24;        // A
153     pixel->c[1] = v&0xFF;       // R
154     pixel->c[2] = (v>>8)&0xFF;  // G
155     pixel->c[3] = (v>>16)&0xFF; // B
156     pixel->s[0] =
157     pixel->s[1] =
158     pixel->s[2] =
159     pixel->s[3] = 8;
160 }
161 
write_pixel(const surface_t * s,context_t * c,uint32_t x,uint32_t y,const pixel_t * pixel)162 void write_pixel(const surface_t* s, context_t* c,
163         uint32_t x, uint32_t y, const pixel_t* pixel)
164 {
165     assert((x < s->width) && (y < s->height));
166 
167     int dither = -1;
168     if (c->state.enables & GGL_ENABLE_DITHER) {
169         dither = c->ditherMatrix[ (x & GGL_DITHER_MASK) +
170                 ((y & GGL_DITHER_MASK)<<GGL_DITHER_ORDER_SHIFT) ];
171     }
172 
173     const GGLFormat* f = &(c->formats[s->format]);
174     int32_t index = x + (s->stride * y);
175     uint8_t* const data = s->data + index * f->size;
176 
177     uint32_t mask = 0;
178     uint32_t v = 0;
179     for (int i=0 ; i<4 ; i++) {
180         const int component_mask = 1 << i;
181         if (f->components>=GGL_LUMINANCE &&
182                 (i==GGLFormat::GREEN || i==GGLFormat::BLUE)) {
183             // destinations L formats don't have G or B
184             continue;
185         }
186         const int l = f->c[i].l;
187         const int h = f->c[i].h;
188         if (h && (c->state.mask.color & component_mask)) {
189             mask |= (((1<<(h-l))-1)<<l);
190             uint32_t u = pixel->c[i];
191             int32_t pixelSize = pixel->s[i];
192             if (pixelSize < (h-l)) {
193                 u = expand(u, pixelSize, h-l);
194                 pixelSize = h-l;
195             }
196             v = downshift_component(v, u, pixelSize, 0, h, l, 0, 0, dither);
197         }
198     }
199 
200     if ((c->state.mask.color != 0xF) ||
201         (c->state.enables & GGL_ENABLE_LOGIC_OP)) {
202         uint32_t d = 0;
203         switch (f->size) {
204             case 1:	d = *data;									break;
205             case 2:	d = *(uint16_t*)data;						break;
206             case 3:	d = (data[2]<<16)|(data[1]<<8)|data[0];     break;
207             case 4:	d = GGL_RGBA_TO_HOST(*(uint32_t*)data);		break;
208         }
209         if (c->state.enables & GGL_ENABLE_LOGIC_OP) {
210             v = logic_op(c->state.logic_op.opcode, v, d);
211             v &= mask;
212         }
213         v |= (d & ~mask);
214     }
215 
216     switch (f->size) {
217         case 1:		*data = v;									break;
218         case 2:		*(uint16_t*)data = v;						break;
219         case 3:
220             data[0] = v;
221             data[1] = v>>8;
222             data[2] = v>>16;
223             break;
224         case 4:		*(uint32_t*)data = GGL_HOST_TO_RGBA(v);     break;
225     }
226 }
227 
logic_op(int op,uint32_t s,uint32_t d)228 static uint32_t logic_op(int op, uint32_t s, uint32_t d)
229 {
230     switch(op) {
231     case GGL_CLEAR:         return 0;
232     case GGL_AND:           return s & d;
233     case GGL_AND_REVERSE:   return s & ~d;
234     case GGL_COPY:          return s;
235     case GGL_AND_INVERTED:  return ~s & d;
236     case GGL_NOOP:          return d;
237     case GGL_XOR:           return s ^ d;
238     case GGL_OR:            return s | d;
239     case GGL_NOR:           return ~(s | d);
240     case GGL_EQUIV:         return ~(s ^ d);
241     case GGL_INVERT:        return ~d;
242     case GGL_OR_REVERSE:    return s | ~d;
243     case GGL_COPY_INVERTED: return ~s;
244     case GGL_OR_INVERTED:   return ~s | d;
245     case GGL_NAND:          return ~(s & d);
246     case GGL_SET:           return ~0;
247     };
248     return s;
249 }
250 
251 
ggl_expand(uint32_t v,int sbits,int dbits)252 uint32_t ggl_expand(uint32_t v, int sbits, int dbits)
253 {
254     return expand(v, sbits, dbits);
255 }
256 
ggl_pack_color(context_t * c,int32_t format,GGLcolor r,GGLcolor g,GGLcolor b,GGLcolor a)257 uint32_t ggl_pack_color(context_t* c, int32_t format,
258         GGLcolor r, GGLcolor g, GGLcolor b, GGLcolor a)
259 {
260     const GGLFormat* f = &(c->formats[format]);
261     uint32_t p = 0;
262     const int32_t hbits = GGL_COLOR_BITS;
263     const int32_t lbits = GGL_COLOR_BITS - 8;
264     p = downshift_component(p, r,   hbits, lbits,  f->rh, f->rl, 0, 1, -1);
265     p = downshift_component(p, g,   hbits, lbits,  f->gh, f->gl, 0, 1, -1);
266     p = downshift_component(p, b,   hbits, lbits,  f->bh, f->bl, 0, 1, -1);
267     p = downshift_component(p, a,   hbits, lbits,  f->ah, f->al, 0, 1, -1);
268     switch (f->size) {
269     case 1: p |= p << 8;    // fallthrough
270     case 2: p |= p << 16;
271     }
272     return p;
273 }
274 
275 // ----------------------------------------------------------------------------
276 
277 // extract a component from a word
extract(uint32_t v,int h,int l,int bits)278 uint32_t extract(uint32_t v, int h, int l, int bits)
279 {
280 	assert(h);
281 	if (l) {
282 		v >>= l;
283 	}
284 	if (h != bits) {
285 		v &= (1<<(h-l))-1;
286 	}
287 	return v;
288 }
289 
290 // expand a component from sbits to dbits
expand(uint32_t v,int sbits,int dbits)291 uint32_t expand(uint32_t v, int sbits, int dbits)
292 {
293     if (dbits > sbits) {
294         assert(sbits);
295         if (sbits==1) {
296             v = (v<<dbits) - v;
297         } else {
298             if (dbits % sbits) {
299                 v <<= (dbits-sbits);
300                 dbits -= sbits;
301                 do {
302                     v |= v>>sbits;
303                     dbits -= sbits;
304                     sbits *= 2;
305                 } while (dbits>0);
306             } else {
307                 dbits -= sbits;
308                 do {
309                     v |= v<<sbits;
310                     dbits -= sbits;
311                     if (sbits*2 < dbits) {
312                         sbits *= 2;
313                     }
314                 } while (dbits > 0);
315             }
316         }
317     }
318 	return v;
319 }
320 
321 // downsample a component from sbits to dbits
322 // and shift / construct the pixel
downshift_component(uint32_t in,uint32_t v,int sh,int sl,int dh,int dl,int ch,int cl,int dither)323 uint32_t downshift_component(	uint32_t in, uint32_t v,
324                                 int sh, int sl,		// src
325                                 int dh, int dl,		// dst
326                                 int ch, int cl,		// clear
327                                 int dither)
328 {
329 	const int sbits = sh-sl;
330 	const int dbits = dh-dl;
331 
332 	assert(sbits>=dbits);
333 
334 
335     if (sbits>dbits) {
336         if (dither>=0) {
337             v -= (v>>dbits);				// fix up
338             const int shift = (GGL_DITHER_BITS - (sbits-dbits));
339             if (shift >= 0)   v += (dither >> shift) << sl;
340             else              v += (dither << (-shift)) << sl;
341         } else {
342             // don't do that right now, so we can reproduce the same
343             // artifacts we get on ARM (Where we don't do this)
344             // -> this is not really needed if we don't dither
345             //if (dBits > 1) { // result already OK if dBits==1
346             //    v -= (v>>dbits);				// fix up
347             //    v += 1 << ((sbits-dbits)-1);	// rounding
348             //}
349         }
350     }
351 
352 
353 	// we need to clear the high bits of the source
354 	if (ch) {
355 		v <<= 32-sh;
356 		sl += 32-sh;
357         sh = 32;
358 	}
359 
360 	if (dl) {
361 		if (cl || (sbits>dbits)) {
362 			v >>= sh-dbits;
363 			sl = 0;
364 			sh = dbits;
365             in |= v<<dl;
366 		} else {
367 			// sbits==dbits and we don't need to clean the lower bits
368 			// so we just have to shift the component to the right location
369             int shift = dh-sh;
370             in |= v<<shift;
371 		}
372 	} else {
373 		// destination starts at bit 0
374 		// ie: sh-dh == sh-dbits
375 		int shift = sh-dh;
376 		if (shift > 0)      in |= v>>shift;
377 		else if (shift < 0) in |= v<<shift;
378 		else                in |= v;
379 	}
380 	return in;
381 }
382 
383 // ----------------------------------------------------------------------------
384 }; // namespace android
385