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
23namespace android {
24// ----------------------------------------------------------------------------
25
26static void read_pixel(const surface_t* s, context_t* c,
27        uint32_t x, uint32_t y, pixel_t* pixel);
28static void write_pixel(const surface_t* s, context_t* c,
29        uint32_t x, uint32_t y, const pixel_t* pixel);
30static void readRGB565(const surface_t* s, context_t* c,
31        uint32_t x, uint32_t y, pixel_t* pixel);
32static void readABGR8888(const surface_t* s, context_t* c,
33        uint32_t x, uint32_t y, pixel_t* pixel);
34
35static uint32_t logic_op(int op, uint32_t s, uint32_t d);
36static uint32_t extract(uint32_t v, int h, int l, int bits);
37static uint32_t expand(uint32_t v, int sbits, int dbits);
38static 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
43void 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
58void 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
73static 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
84void 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
100void 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
111void 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
133void 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
147void 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
162void 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
228static 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
252uint32_t ggl_expand(uint32_t v, int sbits, int dbits)
253{
254    return expand(v, sbits, dbits);
255}
256
257uint32_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
278uint32_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
291uint32_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
323uint32_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