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      1 /*
      2  * Copyright (C) 2007 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include <math.h>
     18 
     19 #include <cutils/compiler.h>
     20 #include <utils/String8.h>
     21 #include <ui/Region.h>
     22 
     23 #include "clz.h"
     24 #include "Transform.h"
     25 
     26 // ---------------------------------------------------------------------------
     27 
     28 namespace android {
     29 
     30 // ---------------------------------------------------------------------------
     31 
     32 Transform::Transform() {
     33     reset();
     34 }
     35 
     36 Transform::Transform(const Transform&  other)
     37     : mMatrix(other.mMatrix), mType(other.mType) {
     38 }
     39 
     40 Transform::Transform(uint32_t orientation) {
     41     set(orientation, 0, 0);
     42 }
     43 
     44 Transform::~Transform() {
     45 }
     46 
     47 static const float EPSILON = 0.0f;
     48 
     49 bool Transform::isZero(float f) {
     50     return fabs(f) <= EPSILON;
     51 }
     52 
     53 bool Transform::absIsOne(float f) {
     54     return isZero(fabs(f) - 1.0f);
     55 }
     56 
     57 Transform Transform::operator * (const Transform& rhs) const
     58 {
     59     if (CC_LIKELY(mType == IDENTITY))
     60         return rhs;
     61 
     62     Transform r(*this);
     63     if (rhs.mType == IDENTITY)
     64         return r;
     65 
     66     // TODO: we could use mType to optimize the matrix multiply
     67     const mat33& A(mMatrix);
     68     const mat33& B(rhs.mMatrix);
     69           mat33& D(r.mMatrix);
     70     for (int i=0 ; i<3 ; i++) {
     71         const float v0 = A[0][i];
     72         const float v1 = A[1][i];
     73         const float v2 = A[2][i];
     74         D[0][i] = v0*B[0][0] + v1*B[0][1] + v2*B[0][2];
     75         D[1][i] = v0*B[1][0] + v1*B[1][1] + v2*B[1][2];
     76         D[2][i] = v0*B[2][0] + v1*B[2][1] + v2*B[2][2];
     77     }
     78     r.mType |= rhs.mType;
     79 
     80     // TODO: we could recompute this value from r and rhs
     81     r.mType &= 0xFF;
     82     r.mType |= UNKNOWN_TYPE;
     83     return r;
     84 }
     85 
     86 float const* Transform::operator [] (int i) const {
     87     return mMatrix[i].v;
     88 }
     89 
     90 bool Transform::transformed() const {
     91     return type() > TRANSLATE;
     92 }
     93 
     94 float Transform::tx() const {
     95     return mMatrix[2][0];
     96 }
     97 
     98 float Transform::ty() const {
     99     return mMatrix[2][1];
    100 }
    101 
    102 void Transform::reset() {
    103     mType = IDENTITY;
    104     for(int i=0 ; i<3 ; i++) {
    105         vec3& v(mMatrix[i]);
    106         for (int j=0 ; j<3 ; j++)
    107             v[j] = ((i==j) ? 1.0f : 0.0f);
    108     }
    109 }
    110 
    111 void Transform::set(float tx, float ty)
    112 {
    113     mMatrix[2][0] = tx;
    114     mMatrix[2][1] = ty;
    115     mMatrix[2][2] = 1.0f;
    116 
    117     if (isZero(tx) && isZero(ty)) {
    118         mType &= ~TRANSLATE;
    119     } else {
    120         mType |= TRANSLATE;
    121     }
    122 }
    123 
    124 void Transform::set(float a, float b, float c, float d)
    125 {
    126     mat33& M(mMatrix);
    127     M[0][0] = a;    M[1][0] = b;
    128     M[0][1] = c;    M[1][1] = d;
    129     M[0][2] = 0;    M[1][2] = 0;
    130     mType = UNKNOWN_TYPE;
    131 }
    132 
    133 status_t Transform::set(uint32_t flags, float w, float h)
    134 {
    135     if (flags & ROT_INVALID) {
    136         // that's not allowed!
    137         reset();
    138         return BAD_VALUE;
    139     }
    140 
    141     Transform H, V, R;
    142     if (flags & ROT_90) {
    143         // w & h are inverted when rotating by 90 degrees
    144         swap(w, h);
    145     }
    146 
    147     if (flags & FLIP_H) {
    148         H.mType = (FLIP_H << 8) | SCALE;
    149         H.mType |= isZero(w) ? IDENTITY : TRANSLATE;
    150         mat33& M(H.mMatrix);
    151         M[0][0] = -1;
    152         M[2][0] = w;
    153     }
    154 
    155     if (flags & FLIP_V) {
    156         V.mType = (FLIP_V << 8) | SCALE;
    157         V.mType |= isZero(h) ? IDENTITY : TRANSLATE;
    158         mat33& M(V.mMatrix);
    159         M[1][1] = -1;
    160         M[2][1] = h;
    161     }
    162 
    163     if (flags & ROT_90) {
    164         const float original_w = h;
    165         R.mType = (ROT_90 << 8) | ROTATE;
    166         R.mType |= isZero(original_w) ? IDENTITY : TRANSLATE;
    167         mat33& M(R.mMatrix);
    168         M[0][0] = 0;    M[1][0] =-1;    M[2][0] = original_w;
    169         M[0][1] = 1;    M[1][1] = 0;
    170     }
    171 
    172     *this = (R*(H*V));
    173     return NO_ERROR;
    174 }
    175 
    176 Transform::vec2 Transform::transform(const vec2& v) const {
    177     vec2 r;
    178     const mat33& M(mMatrix);
    179     r[0] = M[0][0]*v[0] + M[1][0]*v[1] + M[2][0];
    180     r[1] = M[0][1]*v[0] + M[1][1]*v[1] + M[2][1];
    181     return r;
    182 }
    183 
    184 Transform::vec3 Transform::transform(const vec3& v) const {
    185     vec3 r;
    186     const mat33& M(mMatrix);
    187     r[0] = M[0][0]*v[0] + M[1][0]*v[1] + M[2][0]*v[2];
    188     r[1] = M[0][1]*v[0] + M[1][1]*v[1] + M[2][1]*v[2];
    189     r[2] = M[0][2]*v[0] + M[1][2]*v[1] + M[2][2]*v[2];
    190     return r;
    191 }
    192 
    193 void Transform::transform(float* point, int x, int y) const
    194 {
    195     const mat33& M(mMatrix);
    196     vec2 v(x, y);
    197     v = transform(v);
    198     point[0] = v[0];
    199     point[1] = v[1];
    200 }
    201 
    202 Rect Transform::makeBounds(int w, int h) const
    203 {
    204     return transform( Rect(w, h) );
    205 }
    206 
    207 Rect Transform::transform(const Rect& bounds) const
    208 {
    209     Rect r;
    210     vec2 lt( bounds.left,  bounds.top    );
    211     vec2 rt( bounds.right, bounds.top    );
    212     vec2 lb( bounds.left,  bounds.bottom );
    213     vec2 rb( bounds.right, bounds.bottom );
    214 
    215     lt = transform(lt);
    216     rt = transform(rt);
    217     lb = transform(lb);
    218     rb = transform(rb);
    219 
    220     r.left   = floorf(min(lt[0], rt[0], lb[0], rb[0]) + 0.5f);
    221     r.top    = floorf(min(lt[1], rt[1], lb[1], rb[1]) + 0.5f);
    222     r.right  = floorf(max(lt[0], rt[0], lb[0], rb[0]) + 0.5f);
    223     r.bottom = floorf(max(lt[1], rt[1], lb[1], rb[1]) + 0.5f);
    224 
    225     return r;
    226 }
    227 
    228 Region Transform::transform(const Region& reg) const
    229 {
    230     Region out;
    231     if (CC_UNLIKELY(transformed())) {
    232         if (CC_LIKELY(preserveRects())) {
    233             Region::const_iterator it = reg.begin();
    234             Region::const_iterator const end = reg.end();
    235             while (it != end) {
    236                 out.orSelf(transform(*it++));
    237             }
    238         } else {
    239             out.set(transform(reg.bounds()));
    240         }
    241     } else {
    242         int xpos = floorf(tx() + 0.5f);
    243         int ypos = floorf(ty() + 0.5f);
    244         out = reg.translate(xpos, ypos);
    245     }
    246     return out;
    247 }
    248 
    249 uint32_t Transform::type() const
    250 {
    251     if (mType & UNKNOWN_TYPE) {
    252         // recompute what this transform is
    253 
    254         const mat33& M(mMatrix);
    255         const float a = M[0][0];
    256         const float b = M[1][0];
    257         const float c = M[0][1];
    258         const float d = M[1][1];
    259         const float x = M[2][0];
    260         const float y = M[2][1];
    261 
    262         bool scale = false;
    263         uint32_t flags = ROT_0;
    264         if (isZero(b) && isZero(c)) {
    265             if (a<0)    flags |= FLIP_H;
    266             if (d<0)    flags |= FLIP_V;
    267             if (!absIsOne(a) || !absIsOne(d)) {
    268                 scale = true;
    269             }
    270         } else if (isZero(a) && isZero(d)) {
    271             flags |= ROT_90;
    272             if (b>0)    flags |= FLIP_V;
    273             if (c<0)    flags |= FLIP_H;
    274             if (!absIsOne(b) || !absIsOne(c)) {
    275                 scale = true;
    276             }
    277         } else {
    278             // there is a skew component and/or a non 90 degrees rotation
    279             flags = ROT_INVALID;
    280         }
    281 
    282         mType = flags << 8;
    283         if (flags & ROT_INVALID) {
    284             mType |= UNKNOWN;
    285         } else {
    286             if ((flags & ROT_90) || ((flags & ROT_180) == ROT_180))
    287                 mType |= ROTATE;
    288             if (flags & FLIP_H)
    289                 mType ^= SCALE;
    290             if (flags & FLIP_V)
    291                 mType ^= SCALE;
    292             if (scale)
    293                 mType |= SCALE;
    294         }
    295 
    296         if (!isZero(x) || !isZero(y))
    297             mType |= TRANSLATE;
    298     }
    299     return mType;
    300 }
    301 
    302 uint32_t Transform::getType() const {
    303     return type() & 0xFF;
    304 }
    305 
    306 uint32_t Transform::getOrientation() const
    307 {
    308     return (type() >> 8) & 0xFF;
    309 }
    310 
    311 bool Transform::preserveRects() const
    312 {
    313     return (getOrientation() & ROT_INVALID) ? false : true;
    314 }
    315 
    316 void Transform::dump(const char* name) const
    317 {
    318     type(); // updates the type
    319 
    320     String8 flags, type;
    321     const mat33& m(mMatrix);
    322     uint32_t orient = mType >> 8;
    323 
    324     if (orient&ROT_INVALID) {
    325         flags.append("ROT_INVALID ");
    326     } else {
    327         if (orient&ROT_90) {
    328             flags.append("ROT_90 ");
    329         } else {
    330             flags.append("ROT_0 ");
    331         }
    332         if (orient&FLIP_V)
    333             flags.append("FLIP_V ");
    334         if (orient&FLIP_H)
    335             flags.append("FLIP_H ");
    336     }
    337 
    338     if (!(mType&(SCALE|ROTATE|TRANSLATE)))
    339         type.append("IDENTITY ");
    340     if (mType&SCALE)
    341         type.append("SCALE ");
    342     if (mType&ROTATE)
    343         type.append("ROTATE ");
    344     if (mType&TRANSLATE)
    345         type.append("TRANSLATE ");
    346 
    347     ALOGD("%s 0x%08x (%s, %s)", name, mType, flags.string(), type.string());
    348     ALOGD("%.4f  %.4f  %.4f", m[0][0], m[1][0], m[2][0]);
    349     ALOGD("%.4f  %.4f  %.4f", m[0][1], m[1][1], m[2][1]);
    350     ALOGD("%.4f  %.4f  %.4f", m[0][2], m[1][2], m[2][2]);
    351 }
    352 
    353 // ---------------------------------------------------------------------------
    354 
    355 }; // namespace android
    356