include/core/SkTypes.h

/*
 * Copyright 2006 The Android Open Source Project
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkTypes_DEFINED
#define SkTypes_DEFINED

// IWYU pragma: begin_exports
#include "SkPreConfig.h"
#include "SkUserConfig.h"
#include "SkPostConfig.h"
#include <stddef.h>
#include <stdint.h>
// IWYU pragma: end_exports

#include <string.h>
#include <utility>

/** \file SkTypes.h
*/

/** See SkGraphics::GetVersion() to retrieve these at runtime
 */
#define SKIA_VERSION_MAJOR  1
#define SKIA_VERSION_MINOR  0
#define SKIA_VERSION_PATCH  0


/** Called internally if we hit an unrecoverable error.
    The platform implementation must not return, but should either throw
    an exception or otherwise exit.
*/
SK_API extern void sk_abort_no_print(void);

#ifndef SkDebugf
    SK_API void SkDebugf(const char format[], ...);
#endif

// SkASSERT, SkASSERTF and SkASSERT_RELEASE can be used as stand alone assertion expressions, e.g.
//    uint32_t foo(int x) {
//        SkASSERT(x > 4);
//        return x - 4;
//    }
// and are also written to be compatible with constexpr functions:
//    constexpr uint32_t foo(int x) {
//        return SkASSERT(x > 4),
//               x - 4;
//    }
#define SkASSERT_RELEASE(cond) \
        static_cast<void>( (cond) ? (void)0 : []{ SK_ABORT("assert(" #cond ")"); }() )

#ifdef SK_DEBUG
    #define SkASSERT(cond) SkASSERT_RELEASE(cond)
    #define SkASSERTF(cond, fmt, ...) static_cast<void>( (cond) ? (void)0 : [&]{ \
                                          SkDebugf(fmt"\n", __VA_ARGS__);        \
                                          SK_ABORT("assert(" #cond ")");         \
                                      }() )
    #define SkDEBUGFAIL(message)        SK_ABORT(message)
    #define SkDEBUGFAILF(fmt, ...)      SkASSERTF(false, fmt, ##__VA_ARGS__)
    #define SkDEBUGCODE(...)            __VA_ARGS__
    #define SkDEBUGF(args       )       SkDebugf args
    #define SkAssertResult(cond)        SkASSERT(cond)
#else
    #define SkASSERT(cond)            static_cast<void>(0)
    #define SkASSERTF(cond, fmt, ...) static_cast<void>(0)
    #define SkDEBUGFAIL(message)
    #define SkDEBUGFAILF(fmt, ...)
    #define SkDEBUGCODE(...)
    #define SkDEBUGF(args)

    // unlike SkASSERT, this guy executes its condition in the non-debug build.
    // The if is present so that this can be used with functions marked SK_WARN_UNUSED_RESULT.
    #define SkAssertResult(cond)         if (cond) {} do {} while(false)
#endif

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

/**
 *  Fast type for unsigned 8 bits. Use for parameter passing and local
 *  variables, not for storage
 */
typedef unsigned U8CPU;

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

/**
 *  Fast type for unsigned 16 bits. Use for parameter passing and local
 *  variables, not for storage
 */
typedef unsigned U16CPU;

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

#define SK_MaxS16   INT16_MAX
#define SK_MinS16   -SK_MaxS16
#define SK_MaxS32   INT32_MAX
#define SK_MinS32   -SK_MaxS32
#define SK_NaN32    INT32_MIN
static constexpr int64_t SK_MaxS64 = INT64_MAX;
static constexpr int64_t SK_MinS64 = -SK_MaxS64;

static inline constexpr int32_t SkLeftShift(int32_t value, int32_t shift) {
    return (int32_t) ((uint32_t) value << shift);
}

static inline constexpr int64_t SkLeftShift(int64_t value, int32_t shift) {
    return (int64_t) ((uint64_t) value << shift);
}

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

/** Returns the number of entries in an array (not a pointer) */
template <typename T, size_t N> char (&SkArrayCountHelper(T (&array)[N]))[N];
#define SK_ARRAY_COUNT(array) (sizeof(SkArrayCountHelper(array)))

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

template <typename T> static constexpr T SkAlign2(T x) { return (x + 1) >> 1 << 1; }
template <typename T> static constexpr T SkAlign4(T x) { return (x + 3) >> 2 << 2; }
template <typename T> static constexpr T SkAlign8(T x) { return (x + 7) >> 3 << 3; }

template <typename T> static constexpr bool SkIsAlign2(T x) { return 0 == (x & 1); }
template <typename T> static constexpr bool SkIsAlign4(T x) { return 0 == (x & 3); }
template <typename T> static constexpr bool SkIsAlign8(T x) { return 0 == (x & 7); }

template <typename T> static constexpr T SkAlignPtr(T x) {
    return sizeof(void*) == 8 ? SkAlign8(x) : SkAlign4(x);
}
template <typename T> static constexpr bool SkIsAlignPtr(T x) {
    return sizeof(void*) == 8 ? SkIsAlign8(x) : SkIsAlign4(x);
}

typedef uint32_t SkFourByteTag;
static inline constexpr SkFourByteTag SkSetFourByteTag(char a, char b, char c, char d) {
    return (((uint8_t)a << 24) | ((uint8_t)b << 16) | ((uint8_t)c << 8) | (uint8_t)d);
}

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

/** 32 bit integer to hold a unicode value
*/
typedef int32_t SkUnichar;

/** 16 bit unsigned integer to hold a glyph index
*/
typedef uint16_t SkGlyphID;

/** 32 bit value to hold a millisecond duration
 *  Note that SK_MSecMax is about 25 days.
 */
typedef uint32_t SkMSec;
/** maximum representable milliseconds; 24d 20h 31m 23.647s.
*/
#define SK_MSecMax 0x7FFFFFFF

/** The generation IDs in Skia reserve 0 has an invalid marker.
 */
#define SK_InvalidGenID     0
/** The unique IDs in Skia reserve 0 has an invalid marker.
 */
#define SK_InvalidUniqueID  0

/** Generic swap function. Classes with efficient swaps should specialize this function to take
    their fast path. This function is used by SkTSort. */
template <typename T> static inline void SkTSwap(T& a, T& b) {
    T c(std::move(a));
    a = std::move(b);
    b = std::move(c);
}

static inline int32_t SkAbs32(int32_t value) {
    SkASSERT(value != SK_NaN32);  // The most negative int32_t can't be negated.
    if (value < 0) {
        value = -value;
    }
    return value;
}

template <typename T> static inline T SkTAbs(T value) {
    if (value < 0) {
        value = -value;
    }
    return value;
}

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

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

template <typename T> constexpr const T& SkTMin(const T& a, const T& b) {
    return (a < b) ? a : b;
}

template <typename T> constexpr const T& SkTMax(const T& a, const T& b) {
    return (b < a) ? a : b;
}

template <typename T> constexpr const T& SkTClamp(const T& x, const T& lo, const T& hi) {
    return (x < lo) ? lo : SkTMin(x, hi);
}

static inline int32_t SkFastMin32(int32_t value, int32_t max) {
    if (value > max) {
        value = max;
    }
    return value;
}

/** Returns value pinned between min and max, inclusively. */
template <typename T> static constexpr const T& SkTPin(const T& value, const T& min, const T& max) {
    return SkTMax(SkTMin(value, max), min);
}


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

/**
 *  Indicates whether an allocation should count against a cache budget.
 */
enum class SkBudgeted : bool {
    kNo  = false,
    kYes = true
};

/**
 * Indicates whether a backing store needs to be an exact match or can be larger
 * than is strictly necessary
 */
enum class SkBackingFit {
    kApprox,
    kExact
};

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

/**
 *  Use to cast a pointer to a different type, and maintaining strict-aliasing
 */
template <typename Dst> Dst SkTCast(const void* ptr) {
    union {
        const void* src;
        Dst dst;
    } data;
    data.src = ptr;
    return data.dst;
}

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

/** \class SkNoncopyable

SkNoncopyable is the base class for objects that do not want to
be copied. It hides its copy-constructor and its assignment-operator.
*/
class SK_API SkNoncopyable {
public:
    SkNoncopyable() = default;

    SkNoncopyable(SkNoncopyable&&) = default;
    SkNoncopyable& operator =(SkNoncopyable&&) = default;

    SkNoncopyable(const SkNoncopyable&) = delete;
    SkNoncopyable& operator=(const SkNoncopyable&) = delete;
};

#endif