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mirror of https://github.com/vcmi/vcmi.git synced 2024-12-10 09:50:17 +02:00
vcmi/client/renderSDL/SDL_PixelAccess.h
2023-04-30 13:35:54 +03:00

301 lines
8.2 KiB
C++

/*
* SDL_PixelAccess.h, part of VCMI engine
*
* Authors: listed in file AUTHORS in main folder
*
* License: GNU General Public License v2.0 or later
* Full text of license available in license.txt file, in main folder
*
*/
#pragma once
#include "SDL_Extensions.h"
#include <SDL_endian.h>
#include <SDL_pixels.h>
// for accessing channels from pixel in format-independent way
//should be as fast as accessing via pointer at least for 3-4 bytes per pixel
namespace Channels
{
// channel not present in this format
struct channel_empty
{
static STRONG_INLINE void set(uint8_t*, uint8_t) {}
static STRONG_INLINE uint8_t get(const uint8_t *) { return 255;}
};
// channel which uses whole pixel
template<int offset>
struct channel_pixel
{
static STRONG_INLINE void set(uint8_t *ptr, uint8_t value)
{
ptr[offset] = value;
}
static STRONG_INLINE uint8_t get(const uint8_t *ptr)
{
return ptr[offset];
}
};
// channel which uses part of pixel
template <int bits, int mask, int shift>
struct channel_subpx
{
static void STRONG_INLINE set(uint8_t *ptr, uint8_t value)
{
auto * const pixel = (uint16_t *)ptr;
uint8_t subpx = value >> (8 - bits);
*pixel = (*pixel & ~mask) | ((subpx << shift) & mask );
}
static uint8_t STRONG_INLINE get(const uint8_t *ptr)
{
uint8_t subpx = (*((uint16_t *)ptr) & mask) >> shift;
return (subpx << (8 - bits)) | (subpx >> (2*bits - 8));
}
};
template<int bpp>
struct px
{
static channel_empty r;
static channel_empty g;
static channel_empty b;
static channel_empty a;
};
#ifdef VCMI_ENDIAN_BIG
template<>
struct px<4>
{
static channel_pixel<1> r;
static channel_pixel<2> g;
static channel_pixel<3> b;
static channel_pixel<0> a;
};
template<>
struct px<3>
{
static channel_pixel<0> r;
static channel_pixel<1> g;
static channel_pixel<2> b;
static channel_empty a;
};
#else
template<>
struct px<4>
{
static channel_pixel<2> r;
static channel_pixel<1> g;
static channel_pixel<0> b;
static channel_pixel<3> a;
};
template<>
struct px<3>
{
static channel_pixel<2> r;
static channel_pixel<1> g;
static channel_pixel<0> b;
static channel_empty a;
};
#endif
template<>
struct px<2>
{
static channel_subpx<5, 0xF800, 11> r;
static channel_subpx<6, 0x07E0, 5 > g;
static channel_subpx<5, 0x001F, 0 > b;
static channel_empty a;
};
}
template<int bpp, int incrementPtr>
struct ColorPutter
{
static STRONG_INLINE void PutColor(uint8_t *&ptr, const uint8_t & R, const uint8_t & G, const uint8_t & B);
static STRONG_INLINE void PutColor(uint8_t *&ptr, const uint8_t & R, const uint8_t & G, const uint8_t & B, const uint8_t & A);
static STRONG_INLINE void PutColorAlphaSwitch(uint8_t *&ptr, const uint8_t & R, const uint8_t & G, const uint8_t & B, const uint8_t & A);
static STRONG_INLINE void PutColor(uint8_t *&ptr, const SDL_Color & Color);
static STRONG_INLINE void PutColorAlpha(uint8_t *&ptr, const SDL_Color & Color);
static STRONG_INLINE void PutColorRow(uint8_t *&ptr, const SDL_Color & Color, size_t count);
};
template <int incrementPtr>
struct ColorPutter<2, incrementPtr>
{
static STRONG_INLINE void PutColor(uint8_t *&ptr, const uint8_t & R, const uint8_t & G, const uint8_t & B);
static STRONG_INLINE void PutColor(uint8_t *&ptr, const uint8_t & R, const uint8_t & G, const uint8_t & B, const uint8_t & A);
static STRONG_INLINE void PutColorAlphaSwitch(uint8_t *&ptr, const uint8_t & R, const uint8_t & G, const uint8_t & B, const uint8_t & A);
static STRONG_INLINE void PutColor(uint8_t *&ptr, const SDL_Color & Color);
static STRONG_INLINE void PutColorAlpha(uint8_t *&ptr, const SDL_Color & Color);
static STRONG_INLINE void PutColorRow(uint8_t *&ptr, const SDL_Color & Color, size_t count);
};
template<int bpp, int incrementPtr>
STRONG_INLINE void ColorPutter<bpp, incrementPtr>::PutColorAlpha(uint8_t *&ptr, const SDL_Color & Color)
{
PutColor(ptr, Color.r, Color.g, Color.b, Color.a);
}
template<int bpp, int incrementPtr>
STRONG_INLINE void ColorPutter<bpp, incrementPtr>::PutColor(uint8_t *&ptr, const SDL_Color & Color)
{
PutColor(ptr, Color.r, Color.g, Color.b);
}
template<int bpp, int incrementPtr>
STRONG_INLINE void ColorPutter<bpp, incrementPtr>::PutColorAlphaSwitch(uint8_t *&ptr, const uint8_t & R, const uint8_t & G, const uint8_t & B, const uint8_t & A)
{
switch (A)
{
case 0:
ptr += bpp * incrementPtr;
return;
case 255:
PutColor(ptr, R, G, B);
return;
case 128: // optimized
PutColor(ptr,
((uint16_t)R + Channels::px<bpp>::r.get(ptr)) >> 1,
((uint16_t)G + Channels::px<bpp>::g.get(ptr)) >> 1,
((uint16_t)B + Channels::px<bpp>::b.get(ptr)) >> 1);
return;
default:
PutColor(ptr, R, G, B, A);
return;
}
}
template<int bpp, int incrementPtr>
STRONG_INLINE void ColorPutter<bpp, incrementPtr>::PutColor(uint8_t *&ptr, const uint8_t & R, const uint8_t & G, const uint8_t & B, const uint8_t & A)
{
PutColor(ptr, ((((uint32_t)R - (uint32_t)Channels::px<bpp>::r.get(ptr))*(uint32_t)A) >> 8 ) + (uint32_t)Channels::px<bpp>::r.get(ptr),
((((uint32_t)G - (uint32_t)Channels::px<bpp>::g.get(ptr))*(uint32_t)A) >> 8 ) + (uint32_t)Channels::px<bpp>::g.get(ptr),
((((uint32_t)B - (uint32_t)Channels::px<bpp>::b.get(ptr))*(uint32_t)A) >> 8 ) + (uint32_t)Channels::px<bpp>::b.get(ptr));
}
template<int bpp, int incrementPtr>
STRONG_INLINE void ColorPutter<bpp, incrementPtr>::PutColor(uint8_t *&ptr, const uint8_t & R, const uint8_t & G, const uint8_t & B)
{
static_assert(incrementPtr >= -1 && incrementPtr <= +1, "Invalid incrementPtr value!");
if (incrementPtr < 0)
ptr -= bpp;
Channels::px<bpp>::r.set(ptr, R);
Channels::px<bpp>::g.set(ptr, G);
Channels::px<bpp>::b.set(ptr, B);
Channels::px<bpp>::a.set(ptr, 255);
if (incrementPtr > 0)
ptr += bpp;
}
template<int bpp, int incrementPtr>
STRONG_INLINE void ColorPutter<bpp, incrementPtr>::PutColorRow(uint8_t *&ptr, const SDL_Color & Color, size_t count)
{
if (count)
{
uint8_t *pixel = ptr;
PutColor(ptr, Color.r, Color.g, Color.b);
for (size_t i=0; i<count-1; i++)
{
memcpy(ptr, pixel, bpp);
ptr += bpp * incrementPtr;
}
}
}
template <int incrementPtr>
STRONG_INLINE void ColorPutter<2, incrementPtr>::PutColor(uint8_t *&ptr, const uint8_t & R, const uint8_t & G, const uint8_t & B)
{
if(incrementPtr == -1)
ptr -= 2;
auto * const px = (uint16_t *)ptr;
*px = (B>>3) + ((G>>2) << 5) + ((R>>3) << 11); //drop least significant bits of 24 bpp encoded color
if(incrementPtr == 1)
ptr += 2; //bpp
}
template <int incrementPtr>
STRONG_INLINE void ColorPutter<2, incrementPtr>::PutColorAlphaSwitch(uint8_t *&ptr, const uint8_t & R, const uint8_t & G, const uint8_t & B, const uint8_t & A)
{
switch (A)
{
case 0:
ptr += 2 * incrementPtr;
return;
case 255:
PutColor(ptr, R, G, B);
return;
default:
PutColor(ptr, R, G, B, A);
return;
}
}
template <int incrementPtr>
STRONG_INLINE void ColorPutter<2, incrementPtr>::PutColor(uint8_t *&ptr, const uint8_t & R, const uint8_t & G, const uint8_t & B, const uint8_t & A)
{
const int rbit = 5, gbit = 6, bbit = 5; //bits per color
const int rmask = 0xF800, gmask = 0x7E0, bmask = 0x1F;
const int rshift = 11, gshift = 5, bshift = 0;
const uint8_t r5 = (*((uint16_t *)ptr) & rmask) >> rshift,
b5 = (*((uint16_t *)ptr) & bmask) >> bshift,
g5 = (*((uint16_t *)ptr) & gmask) >> gshift;
const uint32_t r8 = (r5 << (8 - rbit)) | (r5 >> (2*rbit - 8)),
g8 = (g5 << (8 - gbit)) | (g5 >> (2*gbit - 8)),
b8 = (b5 << (8 - bbit)) | (b5 >> (2*bbit - 8));
PutColor(ptr,
(((R-r8)*A) >> 8) + r8,
(((G-g8)*A) >> 8) + g8,
(((B-b8)*A) >> 8) + b8);
}
template <int incrementPtr>
STRONG_INLINE void ColorPutter<2, incrementPtr>::PutColorAlpha(uint8_t *&ptr, const SDL_Color & Color)
{
PutColor(ptr, Color.r, Color.g, Color.b, Color.a);
}
template <int incrementPtr>
STRONG_INLINE void ColorPutter<2, incrementPtr>::PutColor(uint8_t *&ptr, const SDL_Color & Color)
{
PutColor(ptr, Color.r, Color.g, Color.b);
}
template <int incrementPtr>
STRONG_INLINE void ColorPutter<2, incrementPtr>::PutColorRow(uint8_t *&ptr, const SDL_Color & Color, size_t count)
{
//drop least significant bits of 24 bpp encoded color
uint16_t pixel = (Color.b>>3) + ((Color.g>>2) << 5) + ((Color.r>>3) << 11);
for (size_t i=0; i<count; i++)
{
memcpy(ptr, &pixel, 2);
if(incrementPtr == -1)
ptr -= 2;
if(incrementPtr == 1)
ptr += 2;
}
}