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https://github.com/ekeeke/Genesis-Plus-GX.git
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155 lines
6.0 KiB
C
155 lines
6.0 KiB
C
/* Sega Genesis/Mega Drive NTSC video filter */
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/* md_ntsc 0.1.2 */
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#ifndef MD_NTSC_H
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#define MD_NTSC_H
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#include "md_ntsc_config.h"
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#ifdef __cplusplus
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extern "C" {
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#endif
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/* Image parameters, ranging from -1.0 to 1.0. Actual internal values shown
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in parenthesis and should remain fairly stable in future versions. */
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typedef struct md_ntsc_setup_t
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{
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/* Basic parameters */
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double hue; /* -1 = -180 degrees +1 = +180 degrees */
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double saturation; /* -1 = grayscale (0.0) +1 = oversaturated colors (2.0) */
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double contrast; /* -1 = dark (0.5) +1 = light (1.5) */
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double brightness; /* -1 = dark (0.5) +1 = light (1.5) */
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double sharpness; /* edge contrast enhancement/blurring */
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/* Advanced parameters */
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double gamma; /* -1 = dark (1.5) +1 = light (0.5) */
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double resolution; /* image resolution */
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double artifacts; /* artifacts caused by color changes */
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double fringing; /* color artifacts caused by brightness changes */
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double bleed; /* color bleed (color resolution reduction) */
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float const* decoder_matrix; /* optional RGB decoder matrix, 6 elements */
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unsigned char* palette_out; /* optional RGB palette out, 3 bytes per color */
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} md_ntsc_setup_t;
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/* Video format presets */
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extern md_ntsc_setup_t const md_ntsc_composite; /* color bleeding + artifacts */
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extern md_ntsc_setup_t const md_ntsc_svideo; /* color bleeding only */
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extern md_ntsc_setup_t const md_ntsc_rgb; /* crisp image */
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extern md_ntsc_setup_t const md_ntsc_monochrome;/* desaturated + artifacts */
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enum { md_ntsc_palette_size = 512 };
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/* Initializes and adjusts parameters. Can be called multiple times on the same
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md_ntsc_t object. Can pass NULL for either parameter. */
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typedef struct md_ntsc_t md_ntsc_t;
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void md_ntsc_init( md_ntsc_t* ntsc, md_ntsc_setup_t const* setup );
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/* Filters one row of pixels. Input pixel format is set by MD_NTSC_IN_FORMAT
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and output RGB depth is set by MD_NTSC_OUT_DEPTH. Both default to 16-bit RGB.
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In_row_width is the number of pixels to get to the next input row. */
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void md_ntsc_blit( md_ntsc_t const* ntsc, MD_NTSC_IN_T const* table, unsigned char* input,
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int in_width, int vline);
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/* Number of output pixels written by blitter for given input width. */
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#define MD_NTSC_OUT_WIDTH( in_width ) \
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(((in_width) - 3) / md_ntsc_in_chunk * md_ntsc_out_chunk + md_ntsc_out_chunk)
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/* Number of input pixels that will fit within given output width. Might be
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rounded down slightly; use MD_NTSC_OUT_WIDTH() on result to find rounded
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value. */
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#define MD_NTSC_IN_WIDTH( out_width ) \
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((out_width) / md_ntsc_out_chunk * md_ntsc_in_chunk - md_ntsc_in_chunk + 3)
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/* Interface for user-defined custom blitters */
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enum { md_ntsc_in_chunk = 4 }; /* number of input pixels read per chunk */
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enum { md_ntsc_out_chunk = 8 }; /* number of output pixels generated per chunk */
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enum { md_ntsc_black = 0 }; /* palette index for black */
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/* Begin outputting row and start three pixels. First pixel will be cut off a bit.
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Declares variables, so must be before first statement in a block (unless you're using C++). */
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#define MD_NTSC_BEGIN_ROW( ntsc, pixel0, pixel1, pixel2, pixel3 ) \
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md_ntsc_rgb_t raw_;\
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unsigned const md_pixel0_ = (pixel0);\
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md_ntsc_rgb_t const* kernel0 = MD_NTSC_IN_FORMAT( ntsc, md_pixel0_ );\
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unsigned const md_pixel1_ = (pixel1);\
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md_ntsc_rgb_t const* kernel1 = MD_NTSC_IN_FORMAT( ntsc, md_pixel1_ );\
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unsigned const md_pixel2_ = (pixel2);\
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md_ntsc_rgb_t const* kernel2 = MD_NTSC_IN_FORMAT( ntsc, md_pixel2_ );\
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unsigned const md_pixel3_ = (pixel3);\
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md_ntsc_rgb_t const* kernel3 = MD_NTSC_IN_FORMAT( ntsc, md_pixel3_ );\
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md_ntsc_rgb_t const* kernelx0;\
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md_ntsc_rgb_t const* kernelx1 = kernel0;\
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md_ntsc_rgb_t const* kernelx2 = kernel0;\
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md_ntsc_rgb_t const* kernelx3 = kernel0
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/* Begin input pixel */
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#define MD_NTSC_COLOR_IN( index, ntsc, color ) \
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MD_NTSC_COLOR_IN_( index, color, MD_NTSC_IN_FORMAT, ntsc )
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/* Generate output pixel */
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#define MD_NTSC_RGB_OUT( x, rgb_out ) {\
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raw_ =\
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kernel0 [x+ 0] + kernel1 [(x+6)%8+16] + kernel2 [(x+4)%8 ] + kernel3 [(x+2)%8+16] +\
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kernelx0 [x+ 8] + kernelx1 [(x+6)%8+24] + kernelx2 [(x+4)%8+8] + kernelx3 [(x+2)%8+24];\
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MD_NTSC_CLAMP_( raw_, 0 );\
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MD_NTSC_RGB_OUT_( rgb_out, 0 );\
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}
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/* private */
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enum { md_ntsc_entry_size = 2 * 16 };
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typedef unsigned long md_ntsc_rgb_t;
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struct md_ntsc_t {
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md_ntsc_rgb_t table [md_ntsc_palette_size] [md_ntsc_entry_size];
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};
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#define MD_NTSC_BGR9( ntsc, n ) (ntsc)->table [n & 0x1FF]
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#define MD_NTSC_RGB16( ntsc, n ) \
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(md_ntsc_rgb_t*) ((char*) (ntsc)->table +\
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((n << 9 & 0x3800) | (n & 0x0700) | (n >> 8 & 0x00E0)) *\
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(md_ntsc_entry_size * sizeof (md_ntsc_rgb_t) / 32))
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#define MD_NTSC_RGB15( ntsc, n ) \
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(md_ntsc_rgb_t*) ((char*) (ntsc)->table +\
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((n << 8 & 0x1C00) | (n & 0x0380) | (n >> 8 & 0x0070)) *\
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(md_ntsc_entry_size * sizeof (md_ntsc_rgb_t) / 16))
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/* common ntsc macros */
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#define md_ntsc_rgb_builder ((1L << 21) | (1 << 11) | (1 << 1))
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#define md_ntsc_clamp_mask (md_ntsc_rgb_builder * 3 / 2)
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#define md_ntsc_clamp_add (md_ntsc_rgb_builder * 0x101)
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#define MD_NTSC_CLAMP_( io, shift ) {\
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md_ntsc_rgb_t sub = (io) >> (9-(shift)) & md_ntsc_clamp_mask;\
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md_ntsc_rgb_t clamp = md_ntsc_clamp_add - sub;\
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io |= clamp;\
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clamp -= sub;\
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io &= clamp;\
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}
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#define MD_NTSC_COLOR_IN_( index, color, ENTRY, table ) {\
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unsigned color_;\
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kernelx##index = kernel##index;\
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kernel##index = (color_ = (color), ENTRY( table, color_ ));\
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}
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/* x is always zero except in snes_ntsc library */
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#if MD_NTSC_OUT_DEPTH == 15
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#define MD_NTSC_RGB_OUT_( rgb_out, x ) {\
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rgb_out = (raw_>>(14-x)& 0x7C00)|(raw_>>(9-x)&0x03E0)|(raw_>>(4-x)&0x001F);\
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}
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#elif MD_NTSC_OUT_DEPTH == 16
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#define MD_NTSC_RGB_OUT_( rgb_out, x ) {\
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rgb_out = (raw_>>(13-x)& 0xF800)|(raw_>>(8-x)&0x07E0)|(raw_>>(4-x)&0x001F);\
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}
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#endif
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#ifdef __cplusplus
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}
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#endif
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#endif
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