include/corecg/SkTypes.h

/* include/corecg/SkTypes.h
**
** Copyright 2006, Google Inc.
**
** 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 SkTypes_DEFINED
#define SkTypes_DEFINED

#include "SkPreConfig.h"
#include "SkUserConfig.h"
#include "SkPostConfig.h"

#include <stdint.h>
#include <stdio.h>

/** \file SkTypes.h
*/

/*
    memory wrappers
*/

extern void  sk_out_of_memory(void);    // platform specific, does not return
extern void  sk_throw(void);            // platform specific, does not return
enum {
    SK_MALLOC_TEMP  = 0x01, //!< hint to sk_malloc that the requested memory will be freed in the scope of the stack frame
    SK_MALLOC_THROW = 0x02  //!< instructs sk_malloc to call sk_throw if the memory cannot be allocated.
};
/** Return a block of memory (at least 4-byte aligned) of at least the
    specified size. If the requested memory cannot be returned, either
    return nil (if SK_MALLOC_TEMP bit is clear) or call sk_throw()
    (if SK_MALLOC_TEMP bit is set). To free the memory, call sk_free().
*/
extern void* sk_malloc_flags(size_t size, unsigned flags);
/** Same as sk_malloc(), but hard coded to pass SK_MALLOC_THROW as the flag
*/
extern void* sk_malloc_throw(size_t size);
/** Same as standard realloc(), but this one never returns nil on failure. It will throw
    an exception if it fails.
*/
extern void* sk_realloc_throw(void* buffer, size_t size);
/** Free memory returned by sk_malloc(). It is safe to pass nil.
*/
extern void  sk_free(void*);

///////////////////////////////////////////////////////////////////////

#define SK_INIT_TO_AVOID_WARNING    = 0

#ifdef SK_DEBUG
    #define SkASSERT(cond)              SK_DEBUGBREAK(cond)
    #define SkDEBUGCODE(code)           code
    #define SkDECLAREPARAM(type, var)   , type var
    #define SkPARAM(var)                , var
//  #define SkDEBUGF(args       )       SkDebugf##args
    #define SkDEBUGF(args       )       SkDebugf args
    void SkDebugf(const char format[], ...);

    #define SkAssertResult(cond)        SkASSERT(cond)
#else
    #define SkASSERT(cond)
    #define SkDEBUGCODE(code)
    #define SkDEBUGF(args)
    #define SkDECLAREPARAM(type, var)
    #define SkPARAM(var)

    // unlike SkASSERT, this guy executes its condition in the non-debug build
    #define SkAssertResult(cond)        cond
#endif

///////////////////////////////////////////////////////////////////////

#ifndef nil
    #define nil         0
#endif

// legacy defines. will be removed before shipping
typedef int8_t      S8;
typedef uint8_t     U8;
typedef int16_t     S16;
typedef uint16_t    U16;
typedef int32_t     S32;
typedef uint32_t    U32;

/** Fast type for signed 8 bits. Use for parameter passing and local variables, not for storage
*/
typedef int         S8CPU;
/** Fast type for unsigned 8 bits. Use for parameter passing and local variables, not for storage
*/
typedef int         S16CPU;
/** Fast type for signed 16 bits. Use for parameter passing and local variables, not for storage
*/
typedef unsigned    U8CPU;
/** Fast type for unsigned 16 bits. Use for parameter passing and local variables, not for storage
*/
typedef unsigned    U16CPU;

/** Meant to be faster than bool (doesn't promise to be 0 or 1, just 0 or non-zero
*/
typedef int         SkBool;
/** Meant to be a small version of bool, for storage purposes. Will be 0 or 1
*/
typedef uint8_t     SkBool8;

#ifdef SK_DEBUG
    int8_t      SkToS8(long);
    uint8_t     SkToU8(size_t);
    int16_t     SkToS16(long);
    uint16_t    SkToU16(size_t);
    int32_t     SkToS32(long);
    uint32_t    SkToU32(size_t);
#else
    #define SkToS8(x)   ((int8_t)(x))
    #define SkToU8(x)   ((uint8_t)(x))
    #define SkToS16(x)  ((int16_t)(x))
    #define SkToU16(x)  ((uint16_t)(x))
    #define SkToS32(x)  ((int32_t)(x))
    #define SkToU32(x)  ((uint32_t)(x))
#endif

/** Returns 0 or 1 based on the condition
*/
#define SkToBool(cond)  ((cond) != 0)

#define SK_MaxS16   32767
#define SK_MinS16   -32767
#define SK_MaxU16   0xFFFF
#define SK_MinU16   0
#define SK_MaxS32   0x7FFFFFFF
#define SK_MinS32   0x80000001
#define SK_MaxU32   0xFFFFFFFF
#define SK_MinU32   0
#define SK_NaN32    0x80000000

#ifndef SK_OFFSETOF
    #define SK_OFFSETOF(type, field)    ((char*)&(((type*)1)->field) - (char*)1)
#endif

/** Returns the number of entries in an array (not a pointer)
*/
#define SK_ARRAY_COUNT(array)       (sizeof(array) / sizeof(array[0]))

/** Returns x rounded up to a multiple of 2
*/
#define SkAlign2(x)     (((x) + 1) >> 1 << 1)
/** Returns x rounded up to a multiple of 4
*/
#define SkAlign4(x)     (((x) + 3) >> 2 << 2)

typedef uint32_t SkFourByteTag;
#define SkSetFourByteTag(a, b, c, d)    (((a) << 24) | ((b) << 16) | ((c) << 8) | (d))

/** 32 bit integer to hold a unicode value
*/
typedef int32_t SkUnichar;
/** 32 bit value to hold a millisecond count
*/
typedef uint32_t SkMSec;
/** 1 second measured in milliseconds
*/
#define SK_MSec1 1000
/** maximum representable milliseconds
*/
#define SK_MSecMax 0x7FFFFFFF
/** Returns a < b for milliseconds, correctly handling wrap-around from 0xFFFFFFFF to 0
*/
#define SkMSec_LT(a, b)     ((int32_t)(a) - (int32_t)(b) < 0)
/** Returns a <= b for milliseconds, correctly handling wrap-around from 0xFFFFFFFF to 0
*/
#define SkMSec_LE(a, b)     ((int32_t)(a) - (int32_t)(b) <= 0)


/****************************************************************************
    The rest of these only build with C++
*/
#ifdef __cplusplus

/** Faster than SkToBool for integral conditions. Returns 0 or 1
*/
inline int Sk32ToBool(uint32_t n)
{
    return (n | (0-n)) >> 31;
}

template <typename T> inline void SkTSwap(T& a, T& b)
{
    T c(a);
    a = b;
    b = c;
}

inline int32_t SkAbs32(int32_t value)
{
#ifdef SK_CPU_HAS_CONDITIONAL_INSTR
    if (value < 0)
        value = -value;
    return value;
#else
    int32_t mask = value >> 31;
    return (value ^ mask) - mask;
#endif
}

inline int32_t SkMax32(int32_t a, int32_t b)
{
    if (a < b)
        a = b;
    return a;
}

inline int32_t SkMin32(int32_t a, int32_t b)
{
    if (a > b)
        a = b;
    return a;
}

inline int32_t SkSign32(int32_t a)
{
    return (a >> 31) | ((unsigned) -a >> 31);
}

inline int32_t SkFastMin32(int32_t value, int32_t max)
{
#ifdef SK_CPU_HAS_CONDITIONAL_INSTR
    if (value > max)
        value = max;
    return value;
#else
    int diff = max - value;
    // clear diff if it is negative (clear if value > max)
    diff &= (diff >> 31);
    return value + diff;
#endif
}

/** Returns signed 32 bit value pinned between min and max, inclusively
*/
inline int32_t SkPin32(int32_t value, int32_t min, int32_t max)
{
#ifdef SK_CPU_HAS_CONDITIONAL_INSTR
    if (value < min)
        value = min;
    if (value > max)
        value = max;
#else
    if (value < min)
        value = min;
    else if (value > max)
        value = max;
#endif
    return value;
}

inline uint32_t SkSetClear32(uint32_t flags, bool cond, unsigned shift)
{
    SkASSERT((int)cond == 0 || (int)cond == 1);
    return flags & ~(1 << shift) | ((int)cond << shift);
}

class SkAutoFree {
public:
    SkAutoFree() : fPtr(NULL) {}
    explicit SkAutoFree(void* ptr) : fPtr(ptr) {}
    ~SkAutoFree() { sk_free(fPtr); }
    
    void*   get() const { return fPtr; }
    void*   set(void* ptr)
    {
        void* prev = fPtr;
        fPtr = ptr;
        return prev;
    }
    void*   detach() { return this->set(NULL); }

private:
    void*   fPtr;
    // illegal
    SkAutoFree(const SkAutoFree&);
    SkAutoFree& operator=(const SkAutoFree&);
};

class SkAutoMalloc : public SkAutoFree {
public:
    explicit SkAutoMalloc(size_t size)
        : SkAutoFree(sk_malloc_flags(size, SK_MALLOC_THROW | SK_MALLOC_TEMP)) {}

    SkAutoMalloc(size_t size, unsigned flags) : SkAutoFree(sk_malloc_flags(size, flags)) {}
};

template <size_t kSize> class SkAutoSMalloc {
public:
    explicit SkAutoSMalloc(size_t size)
    {
        if (size <= kSize)
            fPtr = fStorage;
        else
            fPtr = sk_malloc_flags(size, SK_MALLOC_THROW | SK_MALLOC_TEMP);
    }
    ~SkAutoSMalloc()
    {
        if (fPtr != (void*)fStorage)
            sk_free(fPtr);
    }
    void* get() const { return fPtr; }
private:
    void*       fPtr;
    uint32_t    fStorage[(kSize + 3) >> 2];
    // illegal
    SkAutoSMalloc(const SkAutoSMalloc&);
    SkAutoSMalloc& operator=(const SkAutoSMalloc&);
};

#endif /* C++ */

#endif