include/private/ui/RegionHelper.h - android_frameworks_native - Gitiles

 /*
  * Copyright (C) 2009 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #ifndef ANDROID_UI_PRIVATE_REGION_HELPER_H
 #define ANDROID_UI_PRIVATE_REGION_HELPER_H

 #include <stdint.h>
 #include <sys/types.h>

 namespace android {
 // ----------------------------------------------------------------------------

 template<typename RECT>
 class region_operator
 {
     typedef typename RECT::value_type TYPE;
     static const TYPE max_value = 0x7FFFFFF;

 public:
     /*
      * Common boolean operations:
      * value is computed as 0b101 op 0b110
      *    other boolean operation are possible, simply compute
      *    their corresponding value with the above formulae and use
      *    it when instantiating a region_operator.
      */
     static const uint32_t LHS = 0x5;  // 0b101
     static const uint32_t RHS = 0x6;  // 0b110
     enum {
         op_nand = LHS & ~RHS,
         op_and  = LHS &  RHS,
         op_or   = LHS |  RHS,
         op_xor  = LHS ^  RHS
     };

     struct region {
         RECT const* rects;
         size_t count;
         TYPE dx;
         TYPE dy;
         inline region(const region& rhs)
             : rects(rhs.rects), count(rhs.count), dx(rhs.dx), dy(rhs.dy) { }
         inline region(RECT const* r, size_t c)
             : rects(r), count(c), dx(), dy() { }
         inline region(RECT const* r, size_t c, TYPE dx, TYPE dy)
             : rects(r), count(c), dx(dx), dy(dy) { }
     };

     class region_rasterizer {
         friend class region_operator;
         virtual void operator()(const RECT& rect) = 0;
     public:
         virtual ~region_rasterizer() { };
     };

     inline region_operator(int op, const region& lhs, const region& rhs)
         : op_mask(op), spanner(lhs, rhs)
     {
     }

     void operator()(region_rasterizer& rasterizer) {
         RECT current;
         do {
             SpannerInner spannerInner(spanner.lhs, spanner.rhs);
             int inside = spanner.next(current.top, current.bottom);
             spannerInner.prepare(inside);
             do {
                 TYPE left, right;
                 int inside = spannerInner.next(current.left, current.right);
                 if ((op_mask >> inside) & 1) {
                     if (current.left < current.right &&
                             current.top < current.bottom) {
                         rasterizer(current);
                     }
                 }
             } while(!spannerInner.isDone());
         } while(!spanner.isDone());
     }

 private:
     uint32_t op_mask;

     class SpannerBase
     {
     public:
         enum {
             lhs_before_rhs   = 0,
             lhs_after_rhs    = 1,
             lhs_coincide_rhs = 2
         };

     protected:
         TYPE lhs_head;
         TYPE lhs_tail;
         TYPE rhs_head;
         TYPE rhs_tail;

         inline int next(TYPE& head, TYPE& tail,
                 bool& more_lhs, bool& more_rhs)
         {
             int inside;
             more_lhs = false;
             more_rhs = false;
             if (lhs_head < rhs_head) {
                 inside = lhs_before_rhs;
                 head = lhs_head;
                 if (lhs_tail <= rhs_head) {
                     tail = lhs_tail;
                     more_lhs = true;
                 } else {
                     lhs_head = rhs_head;
                     tail = rhs_head;
                 }
             } else if (rhs_head < lhs_head) {
                 inside = lhs_after_rhs;
                 head = rhs_head;
                 if (rhs_tail <= lhs_head) {
                     tail = rhs_tail;
                     more_rhs = true;
                 } else {
                     rhs_head = lhs_head;
                     tail = lhs_head;
                 }
             } else {
                 inside = lhs_coincide_rhs;
                 head = lhs_head;
                 if (lhs_tail <= rhs_tail) {
                     tail = rhs_head = lhs_tail;
                     more_lhs = true;
                 }
                 if (rhs_tail <= lhs_tail) {
                     tail = lhs_head = rhs_tail;
                     more_rhs = true;
                 }
             }
             return inside;
         }
     };

     class Spanner : protected SpannerBase
     {
         friend class region_operator;
         region lhs;
         region rhs;

     public:
         inline Spanner(const region& lhs, const region& rhs)
             : lhs(lhs), rhs(rhs)
         {
             SpannerBase::lhs_head = lhs.rects->top      + lhs.dy;
             SpannerBase::lhs_tail = lhs.rects->bottom   + lhs.dy;
             SpannerBase::rhs_head = rhs.rects->top      + rhs.dy;
             SpannerBase::rhs_tail = rhs.rects->bottom   + rhs.dy;
         }

         inline bool isDone() const {
             return !rhs.count && !lhs.count;
         }

         inline int next(TYPE& top, TYPE& bottom)
         {
             bool more_lhs = false;
             bool more_rhs = false;
             int inside = SpannerBase::next(top, bottom, more_lhs, more_rhs);
             if (more_lhs) {
                 advance(lhs, SpannerBase::lhs_head, SpannerBase::lhs_tail);
             }
             if (more_rhs) {
                 advance(rhs, SpannerBase::rhs_head, SpannerBase::rhs_tail);
             }
             return inside;
         }

     private:
         static inline
         void advance(region& reg, TYPE& aTop, TYPE& aBottom) {
             // got to next span
             size_t count = reg.count;
             RECT const * rects = reg.rects;
             RECT const * const end = rects + count;
             const int top = rects->top;
             while (rects != end && rects->top == top) {
                 rects++;
                 count--;
             }
             if (rects != end) {
                 aTop    = rects->top    + reg.dy;
                 aBottom = rects->bottom + reg.dy;
             } else {
                 aTop    = max_value;
                 aBottom = max_value;
             }
             reg.rects = rects;
             reg.count = count;
         }
     };

     class SpannerInner : protected SpannerBase
     {
         region lhs;
         region rhs;

     public:
         inline SpannerInner(const region& lhs, const region& rhs)
             : lhs(lhs), rhs(rhs)
         {
         }

         inline void prepare(int inside) {
             if (inside == SpannerBase::lhs_before_rhs) {
                 SpannerBase::lhs_head = lhs.rects->left  + lhs.dx;
                 SpannerBase::lhs_tail = lhs.rects->right + lhs.dx;
                 SpannerBase::rhs_head = max_value;
                 SpannerBase::rhs_tail = max_value;
             } else if (inside == SpannerBase::lhs_after_rhs) {
                 SpannerBase::lhs_head = max_value;
                 SpannerBase::lhs_tail = max_value;
                 SpannerBase::rhs_head = rhs.rects->left  + rhs.dx;
                 SpannerBase::rhs_tail = rhs.rects->right + rhs.dx;
             } else {
                 SpannerBase::lhs_head = lhs.rects->left  + lhs.dx;
                 SpannerBase::lhs_tail = lhs.rects->right + lhs.dx;
                 SpannerBase::rhs_head = rhs.rects->left  + rhs.dx;
                 SpannerBase::rhs_tail = rhs.rects->right + rhs.dx;
             }
         }

         inline bool isDone() const {
             return SpannerBase::lhs_head == max_value &&
                    SpannerBase::rhs_head == max_value;
         }

         inline int next(TYPE& left, TYPE& right)
         {
             bool more_lhs = false;
             bool more_rhs = false;
             int inside = SpannerBase::next(left, right, more_lhs, more_rhs);
             if (more_lhs) {
                 advance(lhs, SpannerBase::lhs_head, SpannerBase::lhs_tail);
             }
             if (more_rhs) {
                 advance(rhs, SpannerBase::rhs_head, SpannerBase::rhs_tail);
             }
             return inside;
         }

     private:
         static inline
         void advance(region& reg, TYPE& left, TYPE& right) {
             if (reg.rects && reg.count) {
                 const int cur_span_top = reg.rects->top;
                 reg.rects++;
                 reg.count--;
                 if (!reg.count || reg.rects->top != cur_span_top) {
                     left  = max_value;
                     right = max_value;
                 } else {
                     left  = reg.rects->left  + reg.dx;
                     right = reg.rects->right + reg.dx;
                 }
             }
         }
     };

     Spanner spanner;
 };

 // ----------------------------------------------------------------------------
 };

 #endif /* ANDROID_UI_PRIVATE_REGION_HELPER_H */
	/*
	* Copyright (C) 2009 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#ifndef ANDROID_UI_PRIVATE_REGION_HELPER_H
	#define ANDROID_UI_PRIVATE_REGION_HELPER_H

	#include <stdint.h>
	#include <sys/types.h>

	namespace android {
	// ----------------------------------------------------------------------------

	template<typename RECT>
	class region_operator
	{
	typedef typename RECT::value_type TYPE;
	static const TYPE max_value = 0x7FFFFFF;

	public:
	/*
	* Common boolean operations:
	* value is computed as 0b101 op 0b110
	* other boolean operation are possible, simply compute
	* their corresponding value with the above formulae and use
	* it when instantiating a region_operator.
	*/
	static const uint32_t LHS = 0x5; // 0b101
	static const uint32_t RHS = 0x6; // 0b110
	enum {
	op_nand = LHS & ~RHS,
	op_and = LHS & RHS,
	op_or = LHS \| RHS,
	op_xor = LHS ^ RHS
	};

	struct region {
	RECT const* rects;
	size_t count;
	TYPE dx;
	TYPE dy;
	inline region(const region& rhs)
	: rects(rhs.rects), count(rhs.count), dx(rhs.dx), dy(rhs.dy) { }
	inline region(RECT const* r, size_t c)
	: rects(r), count(c), dx(), dy() { }
	inline region(RECT const* r, size_t c, TYPE dx, TYPE dy)
	: rects(r), count(c), dx(dx), dy(dy) { }
	};

	class region_rasterizer {
	friend class region_operator;
	virtual void operator()(const RECT& rect) = 0;
	public:
	virtual ~region_rasterizer() { };
	};

	inline region_operator(int op, const region& lhs, const region& rhs)
	: op_mask(op), spanner(lhs, rhs)
	{
	}

	void operator()(region_rasterizer& rasterizer) {
	RECT current;
	do {
	SpannerInner spannerInner(spanner.lhs, spanner.rhs);
	int inside = spanner.next(current.top, current.bottom);
	spannerInner.prepare(inside);
	do {
	TYPE left, right;
	int inside = spannerInner.next(current.left, current.right);
	if ((op_mask >> inside) & 1) {
	if (current.left < current.right &&
	current.top < current.bottom) {
	rasterizer(current);
	}
	}
	} while(!spannerInner.isDone());
	} while(!spanner.isDone());
	}

	private:
	uint32_t op_mask;

	class SpannerBase
	{
	public:
	enum {
	lhs_before_rhs = 0,
	lhs_after_rhs = 1,
	lhs_coincide_rhs = 2
	};

	protected:
	TYPE lhs_head;
	TYPE lhs_tail;
	TYPE rhs_head;
	TYPE rhs_tail;

	inline int next(TYPE& head, TYPE& tail,
	bool& more_lhs, bool& more_rhs)
	{
	int inside;
	more_lhs = false;
	more_rhs = false;
	if (lhs_head < rhs_head) {
	inside = lhs_before_rhs;
	head = lhs_head;
	if (lhs_tail <= rhs_head) {
	tail = lhs_tail;
	more_lhs = true;
	} else {
	lhs_head = rhs_head;
	tail = rhs_head;
	}
	} else if (rhs_head < lhs_head) {
	inside = lhs_after_rhs;
	head = rhs_head;
	if (rhs_tail <= lhs_head) {
	tail = rhs_tail;
	more_rhs = true;
	} else {
	rhs_head = lhs_head;
	tail = lhs_head;
	}
	} else {
	inside = lhs_coincide_rhs;
	head = lhs_head;
	if (lhs_tail <= rhs_tail) {
	tail = rhs_head = lhs_tail;
	more_lhs = true;
	}
	if (rhs_tail <= lhs_tail) {
	tail = lhs_head = rhs_tail;
	more_rhs = true;
	}
	}
	return inside;
	}
	};

	class Spanner : protected SpannerBase
	{
	friend class region_operator;
	region lhs;
	region rhs;

	public:
	inline Spanner(const region& lhs, const region& rhs)
	: lhs(lhs), rhs(rhs)
	{
	SpannerBase::lhs_head = lhs.rects->top + lhs.dy;
	SpannerBase::lhs_tail = lhs.rects->bottom + lhs.dy;
	SpannerBase::rhs_head = rhs.rects->top + rhs.dy;
	SpannerBase::rhs_tail = rhs.rects->bottom + rhs.dy;
	}

	inline bool isDone() const {
	return !rhs.count && !lhs.count;
	}

	inline int next(TYPE& top, TYPE& bottom)
	{
	bool more_lhs = false;
	bool more_rhs = false;
	int inside = SpannerBase::next(top, bottom, more_lhs, more_rhs);
	if (more_lhs) {
	advance(lhs, SpannerBase::lhs_head, SpannerBase::lhs_tail);
	}
	if (more_rhs) {
	advance(rhs, SpannerBase::rhs_head, SpannerBase::rhs_tail);
	}
	return inside;
	}

	private:
	static inline
	void advance(region& reg, TYPE& aTop, TYPE& aBottom) {
	// got to next span
	size_t count = reg.count;
	RECT const * rects = reg.rects;
	RECT const * const end = rects + count;
	const int top = rects->top;
	while (rects != end && rects->top == top) {
	rects++;
	count--;
	}
	if (rects != end) {
	aTop = rects->top + reg.dy;
	aBottom = rects->bottom + reg.dy;
	} else {
	aTop = max_value;
	aBottom = max_value;
	}
	reg.rects = rects;
	reg.count = count;
	}
	};

	class SpannerInner : protected SpannerBase
	{
	region lhs;
	region rhs;

	public:
	inline SpannerInner(const region& lhs, const region& rhs)
	: lhs(lhs), rhs(rhs)
	{
	}

	inline void prepare(int inside) {
	if (inside == SpannerBase::lhs_before_rhs) {
	SpannerBase::lhs_head = lhs.rects->left + lhs.dx;
	SpannerBase::lhs_tail = lhs.rects->right + lhs.dx;
	SpannerBase::rhs_head = max_value;
	SpannerBase::rhs_tail = max_value;
	} else if (inside == SpannerBase::lhs_after_rhs) {
	SpannerBase::lhs_head = max_value;
	SpannerBase::lhs_tail = max_value;
	SpannerBase::rhs_head = rhs.rects->left + rhs.dx;
	SpannerBase::rhs_tail = rhs.rects->right + rhs.dx;
	} else {
	SpannerBase::lhs_head = lhs.rects->left + lhs.dx;
	SpannerBase::lhs_tail = lhs.rects->right + lhs.dx;
	SpannerBase::rhs_head = rhs.rects->left + rhs.dx;
	SpannerBase::rhs_tail = rhs.rects->right + rhs.dx;
	}
	}

	inline bool isDone() const {
	return SpannerBase::lhs_head == max_value &&
	SpannerBase::rhs_head == max_value;
	}

	inline int next(TYPE& left, TYPE& right)
	{
	bool more_lhs = false;
	bool more_rhs = false;
	int inside = SpannerBase::next(left, right, more_lhs, more_rhs);
	if (more_lhs) {
	advance(lhs, SpannerBase::lhs_head, SpannerBase::lhs_tail);
	}
	if (more_rhs) {
	advance(rhs, SpannerBase::rhs_head, SpannerBase::rhs_tail);
	}
	return inside;
	}

	private:
	static inline
	void advance(region& reg, TYPE& left, TYPE& right) {
	if (reg.rects && reg.count) {
	const int cur_span_top = reg.rects->top;
	reg.rects++;
	reg.count--;
	if (!reg.count \|\| reg.rects->top != cur_span_top) {
	left = max_value;
	right = max_value;
	} else {
	left = reg.rects->left + reg.dx;
	right = reg.rects->right + reg.dx;
	}
	}
	}
	};

	Spanner spanner;
	};

	// ----------------------------------------------------------------------------
	};

	#endif /* ANDROID_UI_PRIVATE_REGION_HELPER_H */