// VisualBoyAdvance - Nintendo Gameboy/GameboyAdvance (TM) emulator.
// Copyright (C) 1999-2003 Forgotten
// Copyright (C) 2004 Forgotten and the VBA development team

// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2, or(at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software Foundation,
// Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

#include "GBA.h"
#include "Globals.h"
#include "Gfx.h"

void mode1RenderLine()
{
  u16 *palette = (u16 *)paletteRAM;

  if(DISPCNT & 0x80)
    {
      for(int x = 0; x < 240; x++)
        {
          lineMix[x] = 0x7fff;
        }
      gfxLastVCOUNT = VCOUNT;
      return;
    }

  if(layerEnable & 0x0100)
    {
      gfxDrawTextScreen(BG0CNT, BG0HOFS, BG0VOFS, line0);
    }

  if(layerEnable & 0x0200)
    {
      gfxDrawTextScreen(BG1CNT, BG1HOFS, BG1VOFS, line1);
    }

  if(layerEnable & 0x0400)
    {
      int changed = gfxBG2Changed;
      if(gfxLastVCOUNT > VCOUNT)
        changed = 3;
      gfxDrawRotScreen(BG2CNT, BG2X_L, BG2X_H, BG2Y_L, BG2Y_H,
                       BG2PA, BG2PB, BG2PC, BG2PD,
                       gfxBG2X, gfxBG2Y, changed, line2);
    }

  gfxDrawSprites(lineOBJ);

  u32 backdrop = (READ16LE(&palette[0]) | 0x30000000);

  for(int x = 0; x < 240; x++)
    {
      u32 color = backdrop;
      u8 top = 0x20;

      if(line0[x] < color)
        {
          color = line0[x];
          top = 0x01;
        }

      if((u8)(line1[x]>>24) < (u8)(color >> 24))
        {
          color = line1[x];
          top = 0x02;
        }

      if((u8)(line2[x]>>24) < (u8)(color >> 24))
        {
          color = line2[x];
          top = 0x04;
        }

      if((u8)(lineOBJ[x]>>24) < (u8)(color >> 24))
        {
          color = lineOBJ[x];
          top = 0x10;
        }

      if((top & 0x10) && (color & 0x00010000))
        {
          // semi-transparent OBJ
          u32 back = backdrop;
          u8 top2 = 0x20;

          if((u8)(line0[x]>>24) < (u8)(back >> 24))
            {
              back = line0[x];
              top2 = 0x01;
            }

          if((u8)(line1[x]>>24) < (u8)(back >> 24))
            {
              back = line1[x];
              top2 = 0x02;
            }

          if((u8)(line2[x]>>24) < (u8)(back >> 24))
            {
              back = line2[x];
              top2 = 0x04;
            }

          if(top2 & (BLDMOD>>8))
            color = gfxAlphaBlend(color, back,
                                  coeff[COLEV & 0x1F],
                                  coeff[(COLEV >> 8) & 0x1F]);
          else
            {
              switch((BLDMOD >> 6) & 3)
                {
                case 2:
                  if(BLDMOD & top)
                    color = gfxIncreaseBrightness(color, coeff[COLY & 0x1F]);
                  break;
                case 3:
                  if(BLDMOD & top)
                    color = gfxDecreaseBrightness(color, coeff[COLY & 0x1F]);
                  break;
                }
            }
        }

      lineMix[x] = color;
    }
  gfxBG2Changed = 0;
  gfxLastVCOUNT = VCOUNT;
}

void mode1RenderLineNoWindow()
{
  u16 *palette = (u16 *)paletteRAM;

  if(DISPCNT & 0x80)
    {
      for(int x = 0; x < 240; x++)
        {
          lineMix[x] = 0x7fff;
        }
      gfxLastVCOUNT = VCOUNT;
      return;
    }

  if(layerEnable & 0x0100)
    {
      gfxDrawTextScreen(BG0CNT, BG0HOFS, BG0VOFS, line0);
    }


  if(layerEnable & 0x0200)
    {
      gfxDrawTextScreen(BG1CNT, BG1HOFS, BG1VOFS, line1);
    }

  if(layerEnable & 0x0400)
    {
      int changed = gfxBG2Changed;
      if(gfxLastVCOUNT > VCOUNT)
        changed = 3;
      gfxDrawRotScreen(BG2CNT, BG2X_L, BG2X_H, BG2Y_L, BG2Y_H,
                       BG2PA, BG2PB, BG2PC, BG2PD,
                       gfxBG2X, gfxBG2Y, changed, line2);
    }

  gfxDrawSprites(lineOBJ);

  u32 backdrop = (READ16LE(&palette[0]) | 0x30000000);

  for(int x = 0; x < 240; x++)
    {
      u32 color = backdrop;
      u8 top = 0x20;

      if(line0[x] < color)
        {
          color = line0[x];
          top = 0x01;
        }

      if((u8)(line1[x]>>24) < (u8)(color >> 24))
        {
          color = line1[x];
          top = 0x02;
        }

      if((u8)(line2[x]>>24) < (u8)(color >> 24))
        {
          color = line2[x];
          top = 0x04;
        }

      if((u8)(lineOBJ[x]>>24) < (u8)(color >> 24))
        {
          color = lineOBJ[x];
          top = 0x10;
        }

      if(!(color & 0x00010000))
        {
          switch((BLDMOD >> 6) & 3)
            {
            case 0:
              break;
            case 1:
            {
              if(top & BLDMOD)
                {
                  u32 back = backdrop;
                  u8 top2 = 0x20;
                  if((u8)(line0[x]>>24) < (u8)(back >> 24))
                    {
                      if(top != 0x01)
                        {
                          back = line0[x];
                          top2 = 0x01;
                        }
                    }

                  if((u8)(line1[x]>>24) < (u8)(back >> 24))
                    {
                      if(top != 0x02)
                        {
                          back = line1[x];
                          top2 = 0x02;
                        }
                    }

                  if((u8)(line2[x]>>24) < (u8)(back >> 24))
                    {
                      if(top != 0x04)
                        {
                          back = line2[x];
                          top2 = 0x04;
                        }
                    }

                  if((u8)(lineOBJ[x]>>24) < (u8)(back >> 24))
                    {
                      if(top != 0x10)
                        {
                          back = lineOBJ[x];
                          top2 = 0x10;
                        }
                    }

                  if(top2 & (BLDMOD>>8))
                    color = gfxAlphaBlend(color, back,
                                          coeff[COLEV & 0x1F],
                                          coeff[(COLEV >> 8) & 0x1F]);
                }
            }
            break;
            case 2:
              if(BLDMOD & top)
                color = gfxIncreaseBrightness(color, coeff[COLY & 0x1F]);
              break;
            case 3:
              if(BLDMOD & top)
                color = gfxDecreaseBrightness(color, coeff[COLY & 0x1F]);
              break;
            }
        }
      else
        {
          // semi-transparent OBJ
          u32 back = backdrop;
          u8 top2 = 0x20;

          if((u8)(line0[x]>>24) < (u8)(back >> 24))
            {
              back = line0[x];
              top2 = 0x01;
            }

          if((u8)(line1[x]>>24) < (u8)(back >> 24))
            {
              back = line1[x];
              top2 = 0x02;
            }

          if((u8)(line2[x]>>24) < (u8)(back >> 24))
            {
              back = line2[x];
              top2 = 0x04;
            }

          if(top2 & (BLDMOD>>8))
            color = gfxAlphaBlend(color, back,
                                  coeff[COLEV & 0x1F],
                                  coeff[(COLEV >> 8) & 0x1F]);
          else
            {
              switch((BLDMOD >> 6) & 3)
                {
                case 2:
                  if(BLDMOD & top)
                    color = gfxIncreaseBrightness(color, coeff[COLY & 0x1F]);
                  break;
                case 3:
                  if(BLDMOD & top)
                    color = gfxDecreaseBrightness(color, coeff[COLY & 0x1F]);
                  break;
                }
            }
        }

      lineMix[x] = color;
    }
  gfxBG2Changed = 0;
  gfxLastVCOUNT = VCOUNT;
}

void mode1RenderLineAll()
{
  u16 *palette = (u16 *)paletteRAM;

  if(DISPCNT & 0x80)
    {
      for(int x = 0; x < 240; x++)
        {
          lineMix[x] = 0x7fff;
        }
      gfxLastVCOUNT = VCOUNT;
      return;
    }

  bool inWindow0 = false;
  bool inWindow1 = false;

  if(layerEnable & 0x2000)
    {
      u8 v0 = WIN0V >> 8;
      u8 v1 = WIN0V & 255;
      inWindow0 = ((v0 == v1) && (v0 >= 0xe8));
      if(v1 >= v0)
        inWindow0 |= (VCOUNT >= v0 && VCOUNT < v1);
      else
        inWindow0 |= (VCOUNT >= v0 || VCOUNT < v1);
    }
  if(layerEnable & 0x4000)
    {
      u8 v0 = WIN1V >> 8;
      u8 v1 = WIN1V & 255;
      inWindow1 = ((v0 == v1) && (v0 >= 0xe8));
      if(v1 >= v0)
        inWindow1 |= (VCOUNT >= v0 && VCOUNT < v1);
      else
        inWindow1 |= (VCOUNT >= v0 || VCOUNT < v1);
    }

  if(layerEnable & 0x0100)
    {
      gfxDrawTextScreen(BG0CNT, BG0HOFS, BG0VOFS, line0);
    }

  if(layerEnable & 0x0200)
    {
      gfxDrawTextScreen(BG1CNT, BG1HOFS, BG1VOFS, line1);
    }

  if(layerEnable & 0x0400)
    {
      int changed = gfxBG2Changed;
      if(gfxLastVCOUNT > VCOUNT)
        changed = 3;
      gfxDrawRotScreen(BG2CNT, BG2X_L, BG2X_H, BG2Y_L, BG2Y_H,
                       BG2PA, BG2PB, BG2PC, BG2PD,
                       gfxBG2X, gfxBG2Y, changed, line2);
    }

  gfxDrawSprites(lineOBJ);
  gfxDrawOBJWin(lineOBJWin);

  u32 backdrop = (READ16LE(&palette[0]) | 0x30000000);

  u8 inWin0Mask = WININ & 0xFF;
  u8 inWin1Mask = WININ >> 8;
  u8 outMask = WINOUT & 0xFF;

  for(int x = 0; x < 240; x++)
    {
      u32 color = backdrop;
      u8 top = 0x20;
      u8 mask = outMask;

      if(!(lineOBJWin[x] & 0x80000000))
        {
          mask = WINOUT >> 8;
        }

      if(inWindow1)
        {
          if(gfxInWin1[x])
            mask = inWin1Mask;
        }

      if(inWindow0)
        {
          if(gfxInWin0[x])
            {
              mask = inWin0Mask;
            }
        }

      if(line0[x] < color && (mask & 1))
        {
          color = line0[x];
          top = 0x01;
        }

      if((u8)(line1[x]>>24) < (u8)(color >> 24) && (mask & 2))
        {
          color = line1[x];
          top = 0x02;
        }

      if((u8)(line2[x]>>24) < (u8)(color >> 24) && (mask & 4))
        {
          color = line2[x];
          top = 0x04;
        }

      if((u8)(lineOBJ[x]>>24) < (u8)(color >> 24) && (mask & 16))
        {
          color = lineOBJ[x];
          top = 0x10;
        }

      // special FX on the window
      if(mask & 32)
        {
          if(!(color & 0x00010000))
            {
              switch((BLDMOD >> 6) & 3)
                {
                case 0:
                  break;
                case 1:
                {
                  if(top & BLDMOD)
                    {
                      u32 back = backdrop;
                      u8 top2 = 0x20;
                      if((mask & 1) && (u8)(line0[x]>>24) < (u8)(back >> 24))
                        {
                          if(top != 0x01)
                            {
                              back = line0[x];
                              top2 = 0x01;
                            }
                        }

                      if((mask & 2) && (u8)(line1[x]>>24) < (u8)(back >> 24))
                        {
                          if(top != 0x02)
                            {
                              back = line1[x];
                              top2 = 0x02;
                            }
                        }

                      if((mask & 4) && (u8)(line2[x]>>24) < (u8)(back >> 24))
                        {
                          if(top != 0x04)
                            {
                              back = line2[x];
                              top2 = 0x04;
                            }
                        }

                      if((mask & 16) && (u8)(lineOBJ[x]>>24) < (u8)(back >> 24))
                        {
                          if(top != 0x10)
                            {
                              back = lineOBJ[x];
                              top2 = 0x10;
                            }
                        }

                      if(top2 & (BLDMOD>>8))
                        color = gfxAlphaBlend(color, back,
                                              coeff[COLEV & 0x1F],
                                              coeff[(COLEV >> 8) & 0x1F]);
                    }
                }
                break;
                case 2:
                  if(BLDMOD & top)
                    color = gfxIncreaseBrightness(color, coeff[COLY & 0x1F]);
                  break;
                case 3:
                  if(BLDMOD & top)
                    color = gfxDecreaseBrightness(color, coeff[COLY & 0x1F]);
                  break;
                }
            }
          else
            {
              // semi-transparent OBJ
              u32 back = backdrop;
              u8 top2 = 0x20;

              if((mask & 1) && (u8)(line0[x]>>24) < (u8)(back >> 24))
                {
                  back = line0[x];
                  top2 = 0x01;
                }

              if((mask & 2) && (u8)(line1[x]>>24) < (u8)(back >> 24))
                {
                  back = line1[x];
                  top2 = 0x02;
                }

              if((mask & 4) && (u8)(line2[x]>>24) < (u8)(back >> 24))
                {
                  back = line2[x];
                  top2 = 0x04;
                }

              if(top2 & (BLDMOD>>8))
                color = gfxAlphaBlend(color, back,
                                      coeff[COLEV & 0x1F],
                                      coeff[(COLEV >> 8) & 0x1F]);
              else
                {
                  switch((BLDMOD >> 6) & 3)
                    {
                    case 2:
                      if(BLDMOD & top)
                        color = gfxIncreaseBrightness(color, coeff[COLY & 0x1F]);
                      break;
                    case 3:
                      if(BLDMOD & top)
                        color = gfxDecreaseBrightness(color, coeff[COLY & 0x1F]);
                      break;
                    }
                }
            }
        }
      else if(color & 0x00010000)
        {
          // semi-transparent OBJ
          u32 back = backdrop;
          u8 top2 = 0x20;

          if((mask & 1) && (u8)(line0[x]>>24) < (u8)(back >> 24))
            {
              back = line0[x];
              top2 = 0x01;
            }

          if((mask & 2) && (u8)(line1[x]>>24) < (u8)(back >> 24))
            {
              back = line1[x];
              top2 = 0x02;
            }

          if((mask & 4) && (u8)(line2[x]>>24) < (u8)(back >> 24))
            {
              back = line2[x];
              top2 = 0x04;
            }

          if(top2 & (BLDMOD>>8))
            color = gfxAlphaBlend(color, back,
                                  coeff[COLEV & 0x1F],
                                  coeff[(COLEV >> 8) & 0x1F]);
          else
            {
              switch((BLDMOD >> 6) & 3)
                {
                case 2:
                  if(BLDMOD & top)
                    color = gfxIncreaseBrightness(color, coeff[COLY & 0x1F]);
                  break;
                case 3:
                  if(BLDMOD & top)
                    color = gfxDecreaseBrightness(color, coeff[COLY & 0x1F]);
                  break;
                }
            }
        }

      lineMix[x] = color;
    }
  gfxBG2Changed = 0;
  gfxLastVCOUNT = VCOUNT;
}