/* 
Copyright (C) 1997-2006 ZSNES Team ( zsKnight, _Demo_, pagefault, Nach ) 
 
http://www.zsnes.com 
http://sourceforge.net/projects/zsnes 
 
This program is free software; you can redistribute it and/or 
modify it under the terms of the GNU General Public License 
version 2 as published by the Free Software Foundation. 
 
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., 675 Mass Ave, Cambridge, MA 02139, USA. 
*/ 
 
 
#include "gblhdr.h" 
 
#define BYTE  unsigned char 
#define WORD  unsigned short 
#define DWORD unsigned long 
 
typedef enum 
{ FALSE = 0, TRUE = !FALSE } 
BOOL; 
 
// FUNCTIONS 
extern void hq2x_16b(void); 
extern char hqFilter; 
 
// VIDEO VARIABLES 
extern unsigned char cvidmode; 
extern SDL_Surface *surface; 
extern int SurfaceX, SurfaceY; 
extern int SurfaceLocking; 
extern DWORD BitDepth; 
 
// OPENGL VARIABLES 
static unsigned short *glvidbuffer = 0; 
static GLuint gltextures[3]; 
static int gltexture256, gltexture512; 
static int glfilters = GL_NEAREST; 
static int glscanready = 0; 
extern Uint8 En2xSaI, scanlines; 
extern Uint8 BilinearFilter; 
extern Uint8 FilteredGUI; 
extern Uint8 GUIOn2; 
 
extern unsigned int vidbuffer; 
extern unsigned char curblank; 
extern BYTE GUIRESIZE[]; 
 
unsigned long *  RGBAbuffer; 
 
void gl_clearwin(); 
void UpdateVFrame(void); 
 
void gl_scanlines(void); 
 
void rgb_SHORT_5_6_5_To_bgra_BYTE 
   (unsigned long *Dest, const unsigned short * Src, unsigned int size); 
 
int gl_start(int width, int height, int req_depth, int FullScreen) 
{ 
   Uint32 flags = 
      SDL_DOUBLEBUF | SDL_HWSURFACE | SDL_HWPALETTE | SDL_OPENGL; 
   int i; 
 
   flags |= (GUIRESIZE[cvidmode] ? SDL_RESIZABLE : 0); 
   flags |= (FullScreen ? SDL_FULLSCREEN : 0); 
 
 
   SurfaceX = width; SurfaceY = height; 
   surface = SDL_SetVideoMode(SurfaceX, SurfaceY, req_depth, flags); 
   if (surface == NULL) 
   { 
      fprintf(stderr, "Could not set %dx%d-GL video mode.\n", 
         SurfaceX, SurfaceY); 
      return FALSE; 
   } 
 
   SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1); 
 
   glvidbuffer = (unsigned short *) malloc(512 * 512 * sizeof(short)); 
   gl_clearwin(); 
   SDL_WarpMouse(SurfaceX / 4, SurfaceY / 4); 
 
   // Grab mouse in fullscreen mode 
   FullScreen ? SDL_WM_GrabInput(SDL_GRAB_ON) : 
      SDL_WM_GrabInput(SDL_GRAB_OFF); 
 
   SDL_WM_SetCaption("ZSNES", "ZSNES"); 
   SDL_ShowCursor(0); 
 
   /* Setup some GL stuff */ 
 
   glEnable(GL_TEXTURE_1D); 
   glEnable(GL_TEXTURE_2D); 
 
   glViewport(0, 0, SurfaceX, SurfaceY); 
 
   /* 
    * gltextures[0]: 2D texture, 256*256 
    * gltextures[1]: 2D texture, 512x512 
    * gltextures[2]: 1D texture, 256 lines of alternating alpha 
    */ 
   glGenTextures(3, gltextures); 
   for (i = 0; i < 2; i++) { 
      glBindTexture(GL_TEXTURE_2D, gltextures[i]); 
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, glfilters); 
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, glfilters); 
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP); 
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP); 
   } 
 
   glBindTexture(GL_TEXTURE_2D, gltextures[0]); 
   glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0); 
   glPixelStorei(GL_UNPACK_ROW_LENGTH, 0); 
   glTexImage2D(GL_TEXTURE_2D, 0, 3, 256, 256, 0, 
           GL_BGRA, GL_UNSIGNED_BYTE, 
           NULL); 
 
   glBindTexture(GL_TEXTURE_2D, gltextures[1]); 
   glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0); 
   glPixelStorei(GL_UNPACK_ROW_LENGTH, 0); 
   glTexImage2D(GL_TEXTURE_2D, 0, 3, 512, 512, 0, 
           GL_BGRA, GL_UNSIGNED_BYTE, 
           NULL); 
 
 
   RGBAbuffer = (unsigned long *) malloc (512 * 512 * sizeof(long)); 
   if (scanlines) gl_scanlines(); 
 
   return TRUE; 
} 
 
void gl_end() 
{ 
   glDeleteTextures(3, gltextures); 
   free(glvidbuffer); 
   free(RGBAbuffer); 
} 
 
extern DWORD AddEndBytes; 
extern DWORD NumBytesPerLine; 
extern unsigned char *WinVidMemStart; 
extern unsigned char MMXSupport; 
extern unsigned char NGNoTransp; 
extern unsigned char newengen; 
extern void copy640x480x16bwin(void); 
extern unsigned char SpecialLine[224];   /* 0 if lo-res, > 0 if hi-res */ 
 
void gl_clearwin() 
{ 
   glClear(GL_COLOR_BUFFER_BIT); 
   if (En2xSaI) 
      memset(glvidbuffer, 0, 512 * 448 * 2); 
} 
 
/* gl_drawspan: 
 * Puts a quad on the screen for hires/lores portions, starting at line start, 
 * and ending at line end.. 
 * Builds the 256x256/512x256 textures if gltexture256 or gltexture512 == 0 
 */ 
static void gl_drawspan(int hires, int start, int end) 
{ 
   int i, j; 
 
   switch (hires) 
   { 
      case 0: 
         break; 
      case 3: 
      case 7: 
         hires = 2; 
         break; 
      default: 
         hires = 1; 
         break; 
   } 
 
   if (hires) 
   { 
      if (hires != gltexture512) 
      { 
         unsigned short *vbuf1 = &((unsigned short *) vidbuffer)[16]; 
         unsigned short *vbuf2 = &((unsigned short *) vidbuffer)[75036 * 2 + 16]; 
         unsigned short *vbuf = &glvidbuffer[0]; 
 
         if (hires>1) // mode 7 
         { 
            for (j = 224; j--;) 
            { 
               for (i = 256; i--;) 
                  *vbuf++ = *vbuf1++; 
               for (i = 256; i--;) 
                  *vbuf++ = *vbuf2++; 
               vbuf1 += 32; 
               vbuf2 += 32; 
            } 
 
            glBindTexture(GL_TEXTURE_2D, gltextures[1]); 
            glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0); 
            glPixelStorei(GL_UNPACK_ROW_LENGTH, 256); 
 
            rgb_SHORT_5_6_5_To_bgra_BYTE(RGBAbuffer, 
                        glvidbuffer, 256*448); 
 
 
            glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 256, 
                  448,GL_RGBA, 
                  GL_UNSIGNED_BYTE, 
                  RGBAbuffer); 
 
            gltexture512 = 2; 
 
         } 
         else 
         { 
            for (j = 224; j--;) 
            { 
               for (i = 256; i--;) 
               { 
                  *vbuf++ = *vbuf1++; 
                  *vbuf++ = *vbuf2++; 
               } 
               vbuf1 += 32; 
               vbuf2 += 32;   // skip the two 16-pixel-wide columns 
            } 
 
            glBindTexture(GL_TEXTURE_2D, gltextures[1]); 
            glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0); 
            glPixelStorei(GL_UNPACK_ROW_LENGTH, 512); 
 
            rgb_SHORT_5_6_5_To_bgra_BYTE(RGBAbuffer, 
                        glvidbuffer, 512*224); 
 
            glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 512, 
                  224,GL_RGBA, 
                  GL_UNSIGNED_BYTE, 
                  RGBAbuffer); 
 
            gltexture512 = 1; 
 
         } 
      } 
      if (hires>1) // mode 7 
        { 
          glBindTexture(GL_TEXTURE_2D, gltextures[1]); 
          glBegin(GL_QUADS); 
          glTexCoord2f(0.0f, (224.0 / 256.0) 
             * (start / 224.0)); 
          glVertex2f(-1.0f, (112 - start) / 112.0); 
          glTexCoord2f(0.5f, (224.0 / 256.0) 
             * (start / 224.0)); 
          glVertex2f(1.0f, (112 - start) / 112.0); 
          glTexCoord2f(0.5f, (224.0 / 256.0) 
             * (end / 224.0)); 
          glVertex2f(1.0f, (112 - end) / 112.0); 
          glTexCoord2f(0.0f, (224.0 / 256.0) 
             * (end / 224.0)); 
          glVertex2f(-1.0f, (112 - end) / 112.0); 
          glEnd(); 
        } 
      else 
        { 
          glBindTexture(GL_TEXTURE_2D, gltextures[1]); 
          glBegin(GL_QUADS); 
          glTexCoord2f(0.0f, (224.0 / 512.0) 
             * (start / 224.0)); 
          glVertex2f(-1.0f, (112 - start) / 112.0); 
          glTexCoord2f(1.0f, (224.0 / 512.0) 
             * (start / 224.0)); 
          glVertex2f(1.0f, (112 - start) / 112.0); 
          glTexCoord2f(1.0f, (224.0 / 512.0) 
             * (end / 224.0)); 
          glVertex2f(1.0f, (112 - end) / 112.0); 
          glTexCoord2f(0.0f, (224.0 / 512.0) 
             * (end / 224.0)); 
          glVertex2f(-1.0f, (112 - end) / 112.0); 
          glEnd(); 
 
        } 
 
 
 
   } 
   else 
   { 
      glBindTexture(GL_TEXTURE_2D, gltextures[0]); 
      if (!gltexture256) 
      { 
         glPixelStorei(GL_UNPACK_SKIP_PIXELS, 16); 
         glPixelStorei(GL_UNPACK_ROW_LENGTH, 288); 
 
         rgb_SHORT_5_6_5_To_bgra_BYTE(RGBAbuffer, 
               ((unsigned short *) vidbuffer) + 288, 288*224); 
 
 
         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 256, 
               224,GL_RGBA, 
               GL_UNSIGNED_BYTE,RGBAbuffer); 
 
         glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0); 
         glPixelStorei(GL_UNPACK_ROW_LENGTH, 256); 
 
 
         gltexture256 = 1; 
      } 
 
      glBegin(GL_QUADS); 
         glTexCoord2f(0.0f, (224.0 / 256.0) * (start / 224.0)); 
         glVertex2f(-1.0f, (112 - start) / 112.0); 
         glTexCoord2f(1.0f, (224.0 / 256.0) * (start / 224.0)); 
         glVertex2f(1.0f, (112 - start) / 112.0); 
         glTexCoord2f(1.0f, (224.0 / 256.0) * (end / 224.0)); 
         glVertex2f(1.0f, (112 - end) / 112.0); 
         glTexCoord2f(0.0f, (224.0 / 256.0) * (end / 224.0)); 
         glVertex2f(-1.0f, (112 - end) / 112.0); 
      glEnd(); 
   } 
} 
 
void gl_drawwin() 
{ 
   int i; 
 
   NGNoTransp = 0;      // Set this value to 1 within the appropriate 
            // video mode if you want to add a custom 
            // transparency routine or hardware 
            // transparency.  This only works if 
            // the value of newengen is equal to 1. 
            // (see ProcessTransparencies in newgfx16.asm 
            //  for ZSNES' current transparency code) 
   UpdateVFrame(); 
   if (curblank || cvidmode<6) 
      return; 
 
   if (BilinearFilter) 
   { 
      glfilters = GL_LINEAR; 
      if (GUIOn2 && !FilteredGUI) 
         glfilters = GL_NEAREST; 
   } 
   else 
   { 
      glfilters = GL_NEAREST; 
   } 
 
   if (SurfaceX >= 512 && (hqFilter || En2xSaI)) 
   { 
      AddEndBytes = 0; 
      NumBytesPerLine = 1024; 
      WinVidMemStart = (void *) glvidbuffer; 
 
      if (hqFilter) { 
         hq2x_16b(); 
      } else { 
         copy640x480x16bwin(); 
      } 
 
      /* Display 1 512x448 quad for the 512x448 buffer */ 
      glBindTexture(GL_TEXTURE_2D, gltextures[1]); 
 
 
      glTexEnvi(GL_TEXTURE_2D, GL_TEXTURE_ENV_MODE, GL_DECAL); 
      glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0); 
      glPixelStorei(GL_UNPACK_ROW_LENGTH, 512); 
 
      rgb_SHORT_5_6_5_To_bgra_BYTE(RGBAbuffer, 
             glvidbuffer, 512*448); 
 
      glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 512, 
            448,GL_RGBA, 
            GL_UNSIGNED_BYTE, 
            RGBAbuffer ); 
 
      glDisable (GL_DEPTH_TEST); 
      glDisable (GL_LIGHTING); 
      glDisable (GL_BLEND); 
 
      glBegin(GL_QUADS); 
         glTexCoord2f(0.0f, 0.0f); 
         glVertex3f(-1.0f, 1.0f, -1.0f); 
         glTexCoord2f(1.0f, 0.0f); 
         glVertex3f(1.0f, 1.0f, -1.0f); 
         glTexCoord2f(1.0f, 448.0f / 512.0f); 
         glVertex3f(1.0f, -1.0f, -1.0f); 
         glTexCoord2f(0.0f, 448.0f / 512.0f); 
         glVertex3f(-1.0f, -1.0f, -1.0f); 
      glEnd(); 
   } 
   else 
   { 
      /* 
       * This code splits the hires/lores portions up, and draws 
       * them with gl_drawspan 
       */ 
      int lasthires, lasthires_line = 0; 
 
      gltexture256 = gltexture512 = 0; 
 
      lasthires = SpecialLine[1]; 
      for (i = 0; i < 224; i++) 
      { 
         if (SpecialLine[i + 1]) 
         { 
            if (lasthires) 
               continue; 
            gl_drawspan(lasthires, lasthires_line, i); 
 
            lasthires = SpecialLine[i + 1]; 
            lasthires_line = i; 
         } 
         else 
         { 
            if (!lasthires) 
               continue; 
            gl_drawspan(lasthires, lasthires_line, i); 
 
            lasthires = SpecialLine[i + 1]; 
            lasthires_line = i; 
         } 
      } 
 
      if (i - lasthires_line > 1) 
         gl_drawspan(lasthires, lasthires_line, i); 
 
      /* 
       * This is here rather than right outside this if because the 
       * GUI doesn't allow scanlines to be selected while filters are 
       * on.. There is no technical reason they can't be on while 
       * filters are on, however.  Feel free to change the GUI, and 
       * move this outside the if (En2xSaI) {}, if you do. 
       */ 
      if (scanlines) 
      { 
         glDisable(GL_TEXTURE_2D); 
         glEnable(GL_BLEND); 
 
         if (scanlines != glscanready) gl_scanlines(); 
 
         glBlendFunc(GL_DST_COLOR, GL_ZERO); 
         glBindTexture(GL_TEXTURE_1D, gltextures[2]); 
         glBegin(GL_QUADS); 
         for (i = 0; i < SurfaceY; i += 256) 
         { 
            glTexCoord1f(0.0f); 
            glVertex3f(-1.0f, (SurfaceY - i * 2.0) / SurfaceY, -1.0f); 
            glTexCoord1f(0.0f); 
            glVertex3f(1.0f, (SurfaceY - i * 2.0) / SurfaceY, -1.0f); 
            glTexCoord1f(1.0f); 
            glVertex3f(1.0f, (SurfaceY - (i + 256) * 2.0) / SurfaceY, -1.0f); 
            glTexCoord1f(1.0f); 
            glVertex3f(-1.0f, (SurfaceY - (i + 256) * 2.0) / SurfaceY, -1.0f); 
         } 
         glEnd(); 
 
         glDisable(GL_BLEND); 
         glEnable(GL_TEXTURE_2D); 
      } 
   } 
   SDL_GL_SwapBuffers(); 
} 
 
void gl_scanlines(void) 
{ 
   GLubyte scanbuffer[256][4]; 
   int i, j = scanlines==1 ? 0 : (scanlines==2 ? 192 : 128); 
 
   for (i = 0; i < 256; i += 2) 
   { 
      scanbuffer[i][0] = scanbuffer[i][1] = scanbuffer[i][2] = j; 
      scanbuffer[i][3] = 0xFF; 
 
      scanbuffer[i+1][0] = scanbuffer[i+1][1] = scanbuffer[i+1][2] = 0xFF; 
      scanbuffer[i+1][3] = 0xFF; 
   } 
 
   glBindTexture(GL_TEXTURE_1D, gltextures[2]); 
   glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); 
   glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); 
   glTexImage1D(GL_TEXTURE_1D, 0, GL_RGBA, 256, 0, GL_RGBA, 
           GL_UNSIGNED_BYTE, scanbuffer); 
 
   glscanready = scanlines; 
} 
 
 
/** This convert a RGB 16bits buffer (Src) into a BGRA 32 bits buffer (Dest) */ 
/* size is the number of pixels (short) of Src*/ 
void rgb_SHORT_5_6_5_To_bgra_BYTE(unsigned long *dest, const unsigned short * src, unsigned int size) 
{ 
  while (size--) 
  { 
    *dest  = ((*(char *)src & 0x1F) << 19)        | //B 
             ((*src & 0x7E0)<<5)               | //G 
             ((((char *)src)[1] & 0xF8)) | //R 
             0xFF000000;                         //A 
    src++; 
    dest++; 
  } 
}