ILBM format : Cycling color ranges are loaded (unused so far)

git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@1572 416bcca6-2ee7-4201-b75f-2eb2f807beb1

src/buttons.c

@@ -2422,6 +2422,8 @@ void Draw_button_gradient_style(short x_pos,short y_pos,int technique)
 
 void Load_gradient_data(int index)
 {
+  if (Gradient_array[index].Start>Gradient_array[index].End)
+    Error(0);
   Gradient_lower_bound =Gradient_array[index].Start;
   Gradient_upper_bound =Gradient_array[index].End;
   Gradient_is_inverted          =Gradient_array[index].Inverse;

src/fileformats.c

@@ -388,22 +388,36 @@ void Test_LBM(T_IO_Context * context)
     }
   }
 
+// Inspired by Allegro: storing a 4-character identifier as a 32bit litteral
+#define ID4(a,b,c,d) ((((a)&255)<<24) | (((b)&255)<<16) | (((c)&255)<<8) | (((d)&255)))
+
+/// Skips the current section in an ILBM file.
+/// This function should be called while the file pointer is right
+/// after the 4-character code that identifies the section.
+int LBM_Skip_section(void)
+{
+  dword size;
+  
+  if (!Read_dword_be(LBM_file,&size))
+    return 0;
+  if (size&1)
+    size++;
+  if (fseek(LBM_file,size,SEEK_CUR))
+    return 0;
+  return 1;
+}
+
 // ------------------------- Attendre une section -------------------------
-  byte Wait_for(byte * expected_section)
+byte LBM_Wait_for(byte * expected_section)
 {
   // Valeur retournée: 1=Section trouvée, 0=Section non trouvée (erreur)
-    dword Taille_section;
   byte section_read[4];
 
   if (! Read_bytes(LBM_file,section_read,4))
     return 0;
   while (memcmp(section_read,expected_section,4)) // Sect. pas encore trouvée
   {
-      if (!Read_dword_be(LBM_file,&Taille_section))
+    if (!LBM_Skip_section())
-        return 0;
-      if (Taille_section&1)
-        Taille_section++;
-      if (fseek(LBM_file,Taille_section,SEEK_CUR))
       return 0;
     if (! Read_bytes(LBM_file,section_read,4))
       return 0;
@@ -522,7 +536,7 @@ void Load_LBM(T_IO_Context * context)
   byte  temp_byte;
   short b256;
   dword nb_colors;
-  dword image_size;
+  dword section_size;
   short x_pos;
   short y_pos;
   short counter;
@@ -544,7 +558,7 @@ void Load_LBM(T_IO_Context * context)
     Read_bytes(LBM_file,section,4);
     Read_dword_be(LBM_file,&dummy);
     Read_bytes(LBM_file,format,4);
-    if (!Wait_for((byte *)"BMHD"))
+    if (!LBM_Wait_for((byte *)"BMHD"))
       File_error=1;
     Read_dword_be(LBM_file,&dummy);
 
@@ -564,7 +578,7 @@ void Load_LBM(T_IO_Context * context)
       && (Read_word_be(LBM_file,&header.Y_screen))
       && header.Width && header.Height)
     {
-      if ( (header.BitPlanes) && (Wait_for((byte *)"CMAP")) )
+      if ( (header.BitPlanes) && (LBM_Wait_for((byte *)"CMAP")) )
       {
         Read_dword_be(LBM_file,&nb_colors);
         nb_colors/=3;
@@ -617,9 +631,71 @@ void Load_LBM(T_IO_Context * context)
               if (Read_byte(LBM_file,&temp_byte))
                 File_error=2;
                 
-            if ( (Wait_for((byte *)"BODY")) && (!File_error) )
+            // Keep reading sections until we find the body
+            while (1)
             {
-              Read_dword_be(LBM_file,&image_size);
+              if (! Read_bytes(LBM_file,section,4))
+              {
+                File_error=2;
+                break;
+              }
+              // Found body : stop searching
+              if (!memcmp(section,"BODY",4))
+                break;
+              else if (!memcmp(section,"CRNG",4))
+              {
+                // Handle CRNG
+                
+                // The content of a CRNG is as follows:
+                word padding;
+                word rate;
+                word flags;
+                byte min_col;
+                byte max_col;
+                //
+                
+                if ( (Read_dword_be(LBM_file,&section_size))
+                  && (Read_word_be(LBM_file,&padding))
+                  && (Read_word_be(LBM_file,&rate))
+                  && (Read_word_be(LBM_file,&flags))
+                  && (Read_byte(LBM_file,&min_col))
+                  && (Read_byte(LBM_file,&max_col)))
+                {
+                  if (section_size == 8 && (flags & 1) && min_col != max_col)
+                  {
+                    // Valid cycling range
+                    if (max_col<min_col)
+                    SWAP_BYTES(min_col,max_col)
+                    
+                    context->Cycle_range[context->Color_cycles].Start=min_col;
+                    context->Cycle_range[context->Color_cycles].End=max_col;
+                    context->Cycle_range[context->Color_cycles].Inverse=(flags&2)?1:0;
+                    context->Cycle_range[context->Color_cycles].Speed=rate/78;
+                                        
+                    context->Color_cycles++;
+                  }
+                }
+                else
+                {
+                  File_error=2;
+                  break;
+                }
+              }
+              else
+              {
+                // ignore any number of unknown sections
+                if (!LBM_Skip_section())
+                {
+                  File_error=2;
+                  break;
+                }
+              }
+              
+            }
+
+            if ( !File_error )
+            {
+              Read_dword_be(LBM_file,&section_size);
               //swab((char *)&header.Width ,(char *)&context->Width,2);
               //swab((char *)&header.Height,(char *)&context->Height,2);
               context->Width = header.Width;

src/loadsave.c

@@ -606,7 +606,7 @@ void Load_image(T_IO_Context *context)
 {
   unsigned int index; // index de balayage des formats
   T_Format *format = &(File_formats[2]); // Format du fichier à charger
-
+  int i;
 
   // On place par défaut File_error à vrai au cas où on ne sache pas
   // charger le format du fichier:
@@ -774,6 +774,15 @@ void Load_image(T_IO_Context *context)
           Main_image_width=1;
         if (Main_image_height<1)
           Main_image_height=1;
+
+        // Color cyling ranges:
+        for (i=0; i<context->Color_cycles; i++)
+        {
+          Gradient_array[i].Start=context->Cycle_range[i].Start;
+          Gradient_array[i].End=context->Cycle_range[i].End;
+          Gradient_array[i].Inverse=context->Cycle_range[i].Inverse;
+        }
+
       }
     }
     else if (File_error!=1)

src/loadsave.h

@@ -37,6 +37,14 @@ enum CONTEXT_TYPE {
   CONTEXT_SURFACE,
 };
 
+/// Data for a cycling color series. Heavily cloned from T_Gradient_array.
+typedef struct
+{
+  byte Start;    ///< First color
+  byte End;      ///< Last color
+  byte Inverse;  ///< Boolean, true if the gradient goes in descending order
+  byte Speed;    ///< Frequency of cycling, from 1 (slow) to 64 (fast)
+} T_Color_cycle;
 
 typedef struct
 {
@@ -71,6 +79,9 @@ typedef struct
   /// Original file directory, stored in GIF file
   char * Original_file_directory;
 
+  byte Color_cycles;
+  T_Color_cycle Cycle_range[16];
+
   /// Internal: during load, marks which layer is being loaded.
   short Current_layer;
 

src/main.c

@@ -88,12 +88,41 @@
 
 int test_colorcycling(void* useless)
 {
-  byte r = 0;
+  static byte offset[16]; // static forces init at 0
-  while(1) {
+  int i, color;
+  static SDL_Color PaletteSDL[256];
+  
+  while(!Quitting)
+  {
     SDL_Delay(50);
-    Set_color(0,++r,0,0);
+    // Init palette
+    for(color=0;color<256;color++)
+    {
+      PaletteSDL[color].r=Main_palette[color].R;
+      PaletteSDL[color].g=Main_palette[color].G;
+      PaletteSDL[color].b=Main_palette[color].B;
+    }
+    for (i=0; i<16; i++)
+    {
+      byte len;
+      
+      len=Gradient_array[i].End-Gradient_array[i].Start+1;
+      if (len)
+      {
+        for(color=Gradient_array[i].Start;color<=Gradient_array[i].End;color++)
+        {
+          PaletteSDL[color].r=Main_palette[Gradient_array[i].Start+((color-Gradient_array[i].Start+offset[i])%len)].R;
+          PaletteSDL[color].g=Main_palette[Gradient_array[i].Start+((color-Gradient_array[i].Start+offset[i])%len)].G;
+          PaletteSDL[color].b=Main_palette[Gradient_array[i].Start+((color-Gradient_array[i].Start+offset[i])%len)].B;
+        }
+        offset[i]= (offset[i]+len-1)%len;
       }
     }
+    SDL_SetPalette(Screen_SDL, SDL_PHYSPAL | SDL_LOGPAL, PaletteSDL,0,256);
+  }
+  return 0;
+}
+
 
 //--- Affichage de la syntaxe, et de la liste des modes vidéos disponibles ---
 void Display_syntax(void)