SDF_019_COMMON

//[ THIS_FILE_IS[ SDF_019.COMMON._ ]                 ]//
/** ************************************************ ***
***                                                  ***
***     Live Stream Of Me Working On This Code:      ***
***                                                  ***
*** ************************************************ ***

                twitch.com/kanjicoder

*** ************************************************ ***
***                                                  ***
*** LIVE__________DEMO:  tinyurl.com/SDF-019-DEMO    ***
*** SETUP________VIDEO:  tinyurl.com/SDF-019-SETUP   ***
***                                                  ***
***      SELF______URL:  tinyurl.com/SDF-019-COMMON  ***
***      DOCUMENTATION:  tinyurl.com/SDF-019         ***
***      SOURCE_COMMON:  tinyurl.com/SDF-019-COMMON  ***
***      SOURCE_BUFFER:  tinyurl.com/SDF-019-BUFFER  ***
***      SOURCE__IMAGE:  tinyurl.com/SDF-019-IMAGE   ***
***                                                  ***
*** ************************************************ **/
//:INSTRUCTIONS:IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII://
/** ************************************************ ***

    Click And Drag on the canvas to set pixels.

*** ************************************************ **/
//:IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII:INSTRUCTIONS://
//:MACROS:MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM://

    #define IV2 ivec2
    #define IV3 ivec3
    #define V_4  vec4
    #define V_3  vec3
    #define V_2  vec2
    #define F32 float
    #define I32   int
    #define U32  uint

//:MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM:MACROS://
//:DATA:DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD://


//:DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD:DATA://
//:FUNC:FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF://
//:TILE_DATA_LAYOUT:=================================://

IV3 v3d_CTO_xyc_256( IV3 v3d     ){

    IV3 xyc_256; /**return:value**/

    I32 v_x = v3d.x;
    I32 v_y = v3d.y;
    I32 v_z = v3d.z;

    //[  CODED_WHILE_LOOKING_AT[ #TILE_DATA_LAYOUT#  ]//

    //+@SIXTEEN_FLOORS_OF_EACH_COLOR@+//
    I32 csC = int(trunc( F32(v_z) / 16.0 ));
    I32 csF =( csC * I32(16) );
    I32 csL = v_z - ( csF );

    //+@EACH_FLOOR_IS_64_BY_64@+//
    //+@16_64X64_FLOORS_ON_4X4_GRID@+//
    I32 csY = int(trunc( F32(csL) /        4.0 ));
    I32 csX =                csL - ( csY *(4)   );

    I32 coX = csX * I32(64);
    I32 coY = csY * I32(64);

    I32 p_x = coX + v_x; //: p_x = [ 0 -to- (256-1) ]
    I32 p_y = coY + v_y; //: p_y = [ 0 -to- (256-1) ]

    xyc_256=IV3( p_x , p_y, csC );
    return( xyc_256 );

} IV3 v_i_512_CTO_v3d( I32 v_i_512 ){

    IV3 v3d; /** return:value **/

    //:#WHY_VOB_DEX#://
    //[  CODED_WHILE_LOOKING_AT[ #TILE_DATA_LAYOUT#  ]//

    //:Map onto conceptual 512x512 bitmap, D01.
    I32 p_y_512 = int(trunc( F32( v_i_512 ) / 512.0 ));
    I32 p_x_512 = v_i_512 - ( p_y_512 * I32(512) );

    //:What color floors are you on?
    //:Find Cell Color Quadrant (csC):
    I32 cqX = int(trunc( F32(p_x_512) / 256.0 ));
    I32 cqY = int(trunc( F32(p_y_512) / 256.0 ));

    //: True, but not needed here.
    //: I32 csC = (cqY << 1 ) | ( cqX << 0 );
    //: I32 csF = ( csC * I32( 16 ) );

    //:Map conceptual 512x512 XY to actual 256x256 XY.
    I32 p_x_256 = p_x_512 - ( cqX * 256 );
    I32 p_y_256 = p_y_512 - ( cqY * 256 );

    //:Get 2D representation of your colored floors:
    I32 csX = int(trunc( F32(p_x_256) / 64.0 ) );
    I32 csY = int(trunc( F32(p_y_256) / 64.0 ) );

    //: [v_x,v_y] is local coord inside [csX,csY] cell.
    I32 v_x = p_x_256 - ( csX * I32(64) );
    I32 v_y = p_y_256 - ( csY * I32(64) );

    //: v_z is the INDEX value of [csX,csY]:
    I32 v_z = ( csY * I32(4) ) + csX;

    v3d = IV3( v_x , v_y , v_z );
    return( v3d );

}   U32 v3d_sam_CTO_vob( IV3 v3d , sampler2D sam ){

    U32 vob ; /**return:value**/

    IV3 xyc_256 = v3d_CTO_xyc_256( v3d );

    I32 p_x = xyc_256.x;
    I32 p_y = xyc_256.y;
    I32 csC = xyc_256.z;

    /** sam == iChannel0 in shadertoy. **/
    V_4 c4d = texelFetch( sam,ivec2(p_x,p_y),0);

    vob = U32(  c4d[ csC ] * 255.0 );

//  if( U32( 0 ) == csC /** RED_BYTE **/ ){
//
//      vob = U32(  c4d.x * 255.0 );
//
//  }else
//  if( U32( 1 ) == csC /** RED_BYTE **/ ){
//
//      vob = U32(  c4d.y * 255.0 );
//
//  }else
//  if( U32( 2 ) == csC /** RED_BYTE **/ ){
//
//      vob = U32(  c4d.z * 255.0 );
//
//  }else
//  if( U32( 3 ) == csC /** RED_BYTE **/ ){
//
//      vob = U32(  c4d.w * 255.0 );
//
//  }else{
//      /** THIS IS AN ERROR **/
//  };;

    return( vob );

} U32 v_i_512_sam_CTO_vob(I32 v_i_512 , sampler2D sam){

    U32 vob; /**return:value**/

    IV3 v3d = v_i_512_CTO_v3d( v_i_512 );

    vob = v3d_sam_CTO_vob( v3d , sam) ;
    return( vob );

} //:===============================:TILE_DATA_LAYOUT://
//:FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF:FUNC://
//:MACROS:MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM://

    #undef  IV2
    #undef  IV3
    #undef  V_4
    #undef  V_3
    #undef  V_2
    #undef  F32
    #undef  I32
    #undef  U32

//:MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM:MACROS://