1 /*
2 * Copyright (C) 2011 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 #ifndef ANDROID_VEC_H
18 #define ANDROID_VEC_H
19
20 #include <math.h>
21
22 #include <stdint.h>
23 #include <stddef.h>
24
25 #include "traits.h"
26
27 // -----------------------------------------------------------------------
28
29 #define PURE __attribute__((pure))
30
31 namespace android {
32
33 // -----------------------------------------------------------------------
34 // non-inline helpers
35
36 template <typename TYPE, size_t SIZE>
37 class vec;
38
39 template <typename TYPE, size_t SIZE>
40 struct vbase;
41
42 namespace helpers {
43
min(T a,T b)44 template <typename T> inline T min(T a, T b) { return a<b ? a : b; }
max(T a,T b)45 template <typename T> inline T max(T a, T b) { return a>b ? a : b; }
46
47 template < template<typename T, size_t S> class VEC,
48 typename TYPE, size_t SIZE, size_t S>
doAssign(vec<TYPE,SIZE> & lhs,const VEC<TYPE,S> & rhs)49 vec<TYPE, SIZE>& doAssign(
50 vec<TYPE, SIZE>& lhs, const VEC<TYPE, S>& rhs) {
51 const size_t minSize = min(SIZE, S);
52 const size_t maxSize = max(SIZE, S);
53 for (size_t i=0 ; i<minSize ; i++)
54 lhs[i] = rhs[i];
55 for (size_t i=minSize ; i<maxSize ; i++)
56 lhs[i] = 0;
57 return lhs;
58 }
59
60
61 template <
62 template<typename T, size_t S> class VLHS,
63 template<typename T, size_t S> class VRHS,
64 typename TYPE,
65 size_t SIZE
66 >
doAdd(const VLHS<TYPE,SIZE> & lhs,const VRHS<TYPE,SIZE> & rhs)67 VLHS<TYPE, SIZE> PURE doAdd(
68 const VLHS<TYPE, SIZE>& lhs,
69 const VRHS<TYPE, SIZE>& rhs) {
70 VLHS<TYPE, SIZE> r;
71 for (size_t i=0 ; i<SIZE ; i++)
72 r[i] = lhs[i] + rhs[i];
73 return r;
74 }
75
76 template <
77 template<typename T, size_t S> class VLHS,
78 template<typename T, size_t S> class VRHS,
79 typename TYPE,
80 size_t SIZE
81 >
doSub(const VLHS<TYPE,SIZE> & lhs,const VRHS<TYPE,SIZE> & rhs)82 VLHS<TYPE, SIZE> PURE doSub(
83 const VLHS<TYPE, SIZE>& lhs,
84 const VRHS<TYPE, SIZE>& rhs) {
85 VLHS<TYPE, SIZE> r;
86 for (size_t i=0 ; i<SIZE ; i++)
87 r[i] = lhs[i] - rhs[i];
88 return r;
89 }
90
91 template <
92 template<typename T, size_t S> class VEC,
93 typename TYPE,
94 size_t SIZE
95 >
doMulScalar(const VEC<TYPE,SIZE> & lhs,typename TypeTraits<TYPE>::ParameterType rhs)96 VEC<TYPE, SIZE> PURE doMulScalar(
97 const VEC<TYPE, SIZE>& lhs,
98 typename TypeTraits<TYPE>::ParameterType rhs) {
99 VEC<TYPE, SIZE> r;
100 for (size_t i=0 ; i<SIZE ; i++)
101 r[i] = lhs[i] * rhs;
102 return r;
103 }
104
105 template <
106 template<typename T, size_t S> class VEC,
107 typename TYPE,
108 size_t SIZE
109 >
doScalarMul(typename TypeTraits<TYPE>::ParameterType lhs,const VEC<TYPE,SIZE> & rhs)110 VEC<TYPE, SIZE> PURE doScalarMul(
111 typename TypeTraits<TYPE>::ParameterType lhs,
112 const VEC<TYPE, SIZE>& rhs) {
113 VEC<TYPE, SIZE> r;
114 for (size_t i=0 ; i<SIZE ; i++)
115 r[i] = lhs * rhs[i];
116 return r;
117 }
118
119 }; // namespace helpers
120
121 // -----------------------------------------------------------------------
122 // Below we define the mathematical operators for vectors.
123 // We use template template arguments so we can generically
124 // handle the case where the right-hand-size and left-hand-side are
125 // different vector types (but with same value_type and size).
126 // This is needed for performance when using ".xy{z}" element access
127 // on vec<>. Without this, an extra conversion to vec<> would be needed.
128 //
129 // example:
130 // vec4_t a;
131 // vec3_t b;
132 // vec3_t c = a.xyz + b;
133 //
134 // "a.xyz + b" is a mixed-operation between a vbase<> and a vec<>, requiring
135 // a conversion of vbase<> to vec<>. The template gunk below avoids this,
136 // by allowing the addition on these different vector types directly
137 //
138
139 template <
140 template<typename T, size_t S> class VLHS,
141 template<typename T, size_t S> class VRHS,
142 typename TYPE,
143 size_t SIZE
144 >
145 inline VLHS<TYPE, SIZE> PURE operator + (
146 const VLHS<TYPE, SIZE>& lhs,
147 const VRHS<TYPE, SIZE>& rhs) {
148 return helpers::doAdd(lhs, rhs);
149 }
150
151 template <
152 template<typename T, size_t S> class VLHS,
153 template<typename T, size_t S> class VRHS,
154 typename TYPE,
155 size_t SIZE
156 >
157 inline VLHS<TYPE, SIZE> PURE operator - (
158 const VLHS<TYPE, SIZE>& lhs,
159 const VRHS<TYPE, SIZE>& rhs) {
160 return helpers::doSub(lhs, rhs);
161 }
162
163 template <
164 template<typename T, size_t S> class VEC,
165 typename TYPE,
166 size_t SIZE
167 >
168 inline VEC<TYPE, SIZE> PURE operator * (
169 const VEC<TYPE, SIZE>& lhs,
170 typename TypeTraits<TYPE>::ParameterType rhs) {
171 return helpers::doMulScalar(lhs, rhs);
172 }
173
174 template <
175 template<typename T, size_t S> class VEC,
176 typename TYPE,
177 size_t SIZE
178 >
179 inline VEC<TYPE, SIZE> PURE operator * (
180 typename TypeTraits<TYPE>::ParameterType lhs,
181 const VEC<TYPE, SIZE>& rhs) {
182 return helpers::doScalarMul(lhs, rhs);
183 }
184
185
186 template <
187 template<typename T, size_t S> class VLHS,
188 template<typename T, size_t S> class VRHS,
189 typename TYPE,
190 size_t SIZE
191 >
dot_product(const VLHS<TYPE,SIZE> & lhs,const VRHS<TYPE,SIZE> & rhs)192 TYPE PURE dot_product(
193 const VLHS<TYPE, SIZE>& lhs,
194 const VRHS<TYPE, SIZE>& rhs) {
195 TYPE r(0);
196 for (size_t i=0 ; i<SIZE ; i++)
197 r += lhs[i] * rhs[i];
198 return r;
199 }
200
201 template <
202 template<typename T, size_t S> class V,
203 typename TYPE,
204 size_t SIZE
205 >
length(const V<TYPE,SIZE> & v)206 TYPE PURE length(const V<TYPE, SIZE>& v) {
207 return sqrt(dot_product(v, v));
208 }
209
210 template <
211 template<typename T, size_t S> class V,
212 typename TYPE,
213 size_t SIZE
214 >
length_squared(const V<TYPE,SIZE> & v)215 TYPE PURE length_squared(const V<TYPE, SIZE>& v) {
216 return dot_product(v, v);
217 }
218
219 template <
220 template<typename T, size_t S> class V,
221 typename TYPE,
222 size_t SIZE
223 >
normalize(const V<TYPE,SIZE> & v)224 V<TYPE, SIZE> PURE normalize(const V<TYPE, SIZE>& v) {
225 return v * (1/length(v));
226 }
227
228 template <
229 template<typename T, size_t S> class VLHS,
230 template<typename T, size_t S> class VRHS,
231 typename TYPE
232 >
cross_product(const VLHS<TYPE,3> & u,const VRHS<TYPE,3> & v)233 VLHS<TYPE, 3> PURE cross_product(
234 const VLHS<TYPE, 3>& u,
235 const VRHS<TYPE, 3>& v) {
236 VLHS<TYPE, 3> r;
237 r.x = u.y*v.z - u.z*v.y;
238 r.y = u.z*v.x - u.x*v.z;
239 r.z = u.x*v.y - u.y*v.x;
240 return r;
241 }
242
243
244 template <typename TYPE, size_t SIZE>
245 vec<TYPE, SIZE> PURE operator - (const vec<TYPE, SIZE>& lhs) {
246 vec<TYPE, SIZE> r;
247 for (size_t i=0 ; i<SIZE ; i++)
248 r[i] = -lhs[i];
249 return r;
250 }
251
252 // -----------------------------------------------------------------------
253
254 // This our basic vector type, it just implements the data storage
255 // and accessors.
256
257 template <typename TYPE, size_t SIZE>
258 struct vbase {
259 TYPE v[SIZE];
260 inline const TYPE& operator[](size_t i) const { return v[i]; }
261 inline TYPE& operator[](size_t i) { return v[i]; }
262 };
263 template<> struct vbase<float, 2> {
264 union {
265 float v[2];
266 struct { float x, y; };
267 struct { float s, t; };
268 };
269 inline const float& operator[](size_t i) const { return v[i]; }
270 inline float& operator[](size_t i) { return v[i]; }
271 };
272 template<> struct vbase<float, 3> {
273 union {
274 float v[3];
275 struct { float x, y, z; };
276 struct { float s, t, r; };
277 vbase<float, 2> xy;
278 vbase<float, 2> st;
279 };
280 inline const float& operator[](size_t i) const { return v[i]; }
281 inline float& operator[](size_t i) { return v[i]; }
282 };
283 template<> struct vbase<float, 4> {
284 union {
285 float v[4];
286 struct { float x, y, z, w; };
287 struct { float s, t, r, q; };
288 vbase<float, 3> xyz;
289 vbase<float, 3> str;
290 vbase<float, 2> xy;
291 vbase<float, 2> st;
292 };
293 inline const float& operator[](size_t i) const { return v[i]; }
294 inline float& operator[](size_t i) { return v[i]; }
295 };
296
297 // -----------------------------------------------------------------------
298
299 template <typename TYPE, size_t SIZE>
300 class vec : public vbase<TYPE, SIZE>
301 {
302 typedef typename TypeTraits<TYPE>::ParameterType pTYPE;
303 typedef vbase<TYPE, SIZE> base;
304
305 public:
306 // STL-like interface.
307 typedef TYPE value_type;
308 typedef TYPE& reference;
309 typedef TYPE const& const_reference;
310 typedef size_t size_type;
311
312 typedef TYPE* iterator;
313 typedef TYPE const* const_iterator;
314 iterator begin() { return base::v; }
315 iterator end() { return base::v + SIZE; }
316 const_iterator begin() const { return base::v; }
317 const_iterator end() const { return base::v + SIZE; }
318 size_type size() const { return SIZE; }
319
320 // -----------------------------------------------------------------------
321 // default constructors
322
323 vec() { }
324 vec(const vec& rhs) : base(rhs) { }
325 vec(const base& rhs) : base(rhs) { }
326
327 // -----------------------------------------------------------------------
328 // conversion constructors
329
330 vec(pTYPE rhs) {
331 for (size_t i=0 ; i<SIZE ; i++)
332 base::operator[](i) = rhs;
333 }
334
335 template < template<typename T, size_t S> class VEC, size_t S>
336 explicit vec(const VEC<TYPE, S>& rhs) {
337 helpers::doAssign(*this, rhs);
338 }
339
340 explicit vec(TYPE const* array) {
341 for (size_t i=0 ; i<SIZE ; i++)
342 base::operator[](i) = array[i];
343 }
344
345 // -----------------------------------------------------------------------
346 // Assignment
347
348 vec& operator = (const vec& rhs) {
349 base::operator=(rhs);
350 return *this;
351 }
352
353 vec& operator = (const base& rhs) {
354 base::operator=(rhs);
355 return *this;
356 }
357
358 vec& operator = (pTYPE rhs) {
359 for (size_t i=0 ; i<SIZE ; i++)
360 base::operator[](i) = rhs;
361 return *this;
362 }
363
364 template < template<typename T, size_t S> class VEC, size_t S>
365 vec& operator = (const VEC<TYPE, S>& rhs) {
366 return helpers::doAssign(*this, rhs);
367 }
368
369 // -----------------------------------------------------------------------
370 // operation-assignment
371
372 vec& operator += (const vec& rhs);
373 vec& operator -= (const vec& rhs);
374 vec& operator *= (pTYPE rhs);
375
376 // -----------------------------------------------------------------------
377 // non-member function declaration and definition
378 // NOTE: we declare the non-member function as friend inside the class
379 // so that they are known to the compiler when the class is instantiated.
380 // This helps the compiler doing template argument deduction when the
381 // passed types are not identical. Essentially this helps with
382 // type conversion so that you can multiply a vec<float> by an scalar int
383 // (for instance).
384
385 friend inline vec PURE operator + (const vec& lhs, const vec& rhs) {
386 return helpers::doAdd(lhs, rhs);
387 }
388 friend inline vec PURE operator - (const vec& lhs, const vec& rhs) {
389 return helpers::doSub(lhs, rhs);
390 }
391 friend inline vec PURE operator * (const vec& lhs, pTYPE v) {
392 return helpers::doMulScalar(lhs, v);
393 }
394 friend inline vec PURE operator * (pTYPE v, const vec& rhs) {
395 return helpers::doScalarMul(v, rhs);
396 }
397 friend inline TYPE PURE dot_product(const vec& lhs, const vec& rhs) {
398 return android::dot_product(lhs, rhs);
399 }
400 };
401
402 // -----------------------------------------------------------------------
403
404 template <typename TYPE, size_t SIZE>
405 vec<TYPE, SIZE>& vec<TYPE, SIZE>::operator += (const vec<TYPE, SIZE>& rhs) {
406 vec<TYPE, SIZE>& lhs(*this);
407 for (size_t i=0 ; i<SIZE ; i++)
408 lhs[i] += rhs[i];
409 return lhs;
410 }
411
412 template <typename TYPE, size_t SIZE>
413 vec<TYPE, SIZE>& vec<TYPE, SIZE>::operator -= (const vec<TYPE, SIZE>& rhs) {
414 vec<TYPE, SIZE>& lhs(*this);
415 for (size_t i=0 ; i<SIZE ; i++)
416 lhs[i] -= rhs[i];
417 return lhs;
418 }
419
420 template <typename TYPE, size_t SIZE>
421 vec<TYPE, SIZE>& vec<TYPE, SIZE>::operator *= (vec<TYPE, SIZE>::pTYPE rhs) {
422 vec<TYPE, SIZE>& lhs(*this);
423 for (size_t i=0 ; i<SIZE ; i++)
424 lhs[i] *= rhs;
425 return lhs;
426 }
427
428 // -----------------------------------------------------------------------
429
430 typedef vec<float, 2> vec2_t;
431 typedef vec<float, 3> vec3_t;
432 typedef vec<float, 4> vec4_t;
433
434 // -----------------------------------------------------------------------
435
436 }; // namespace android
437
438 #endif /* ANDROID_VEC_H */
439