opengl.shader: Allow shaders to be built from snippets.

3-mid/opengl/assets/shader/lit_textured_x2.frag

@@ -1,5 +1,3 @@
-#version 140
-
 struct light
 {
    vec4    Site;
@@ -16,10 +14,6 @@ uniform mat3        inverse_model_Rotation;
 uniform vec3        camera_Site;
 uniform vec3        specular_Color;    // The materials specular color.
 
-uniform int         texture_Count;
-uniform sampler2D   Textures [32];
-uniform float       Fade     [32];
-
 uniform int         light_Count;
 uniform light       Lights [10];
 
@@ -32,6 +26,8 @@ in  float  frag_Shine;
 out vec4   final_Color;
 
 
+
+
 vec3
 apply_Light (light   Light, 
              vec3    surface_Color, 
@@ -95,33 +91,16 @@ apply_Light (light   Light,
 
 
 
+
 void
 main()
 {
     vec3   surface_Site      = vec3 (  model_Transform
                                      * vec4 (frag_Site, 1));
-                                   
+    vec4   surface_Color     = apply_Texturing (frag_Coords);
-    vec4   surface_Color = vec4 (0);
-    
-    for (int i = 0;   i < texture_Count;   ++i)
-    {
-//        surface_Color += texture (Textures [i],
-//                                  frag_Coords);
-
-        surface_Color.rgb +=   texture (Textures [i],frag_Coords).rgb
-                             * texture (Textures [i],frag_Coords).a
-                             * (1.0 - Fade [i]);
-                                      
-        surface_Color.a    = max (surface_Color.a, texture (Textures [i],
-                                                            frag_Coords).a);
-    }
-         
-    surface_Color = surface_Color;   //   / texture_Count;
-
     vec3   Surface_to_Camera = normalize (camera_Site - surface_Site);
     vec3   Normal            = normalize (  frag_Normal
                                           * inverse_model_Rotation);
-
     // Combine color from all the lights.
     //
     vec3   linear_Color = vec3 (0);
@@ -135,8 +114,7 @@ main()
                                      Surface_to_Camera);
     }
     
-    vec3   Gamma = vec3 (1.0 / 2.2);
+    vec3  Gamma = vec3 (1.0 / 2.2);
-
     final_Color = vec4 (pow (linear_Color,     // Final color (after gamma correction).
                              Gamma),
                         surface_Color.a);

3-mid/opengl/source/lean/geometry/opengl-geometry-lit_textured_x2.adb

@@ -87,8 +87,10 @@ is
             white_Texture := openGL.Texture.Forge.to_Texture (white_Image);
 
             vertex_Shader  .define (Shader.Vertex,   "assets/opengl/shader/lit_textured_x2.vert");
-            fragment_Shader.define (Shader.Fragment, "assets/opengl/shader/lit_textured_x2.frag");
 
+            fragment_Shader.define (Shader.Fragment, (asset_Names' (1 => to_Asset ("assets/opengl/shader/version.header"),
+                                                                    2 => to_Asset ("assets/opengl/shader/texturing.frag"),
+                                                                    3 => to_Asset ("assets/opengl/shader/lit_textured_x2.frag"))));
             the_Program := new openGL.Program.lit.item;
             the_Program.define (  vertex_Shader'Access,
                                 fragment_Shader'Access);

3-mid/opengl/source/lean/shader/opengl-shader.adb

@@ -11,6 +11,9 @@ with
 
      interfaces.C.Strings;
 
+-- use ada.Text_IO;
+
+
 package body openGL.Shader
 is
    use GL.lean,
@@ -22,23 +25,71 @@ is
    function read_text_File (Filename : in String) return C.char_array;
 
 
+
+
    ---------
    --  Forge
    --
 
-   procedure define (Self : in out Item;   Kind            : in shader.Kind;
+   function to_C_char_array (shader_Filename : in String) return C.char_array
-                                           source_Filename : in String)
+   is
+      use type interfaces.C.char_array;
+   begin
+      return   read_text_File (shader_Filename)
+             & (1 => C.char (ada.Characters.Latin_1.NUL));
+   end to_C_char_array;
+
+
+
+
+   function to_C_char_array (shader_Snippets : in asset_Names) return C.char_array
+   is
+      use type interfaces.C.char_array;
+
+      snippet_Id : Natural := 0;
+
+      function combine_Snippets return C.char_array
+      is
+      begin
+         snippet_Id := snippet_Id + 1;
+
+         if snippet_Id < shader_Snippets'Last
+         then
+            return read_text_File (to_String (shader_Snippets (snippet_Id))) & combine_Snippets;
+         else
+            return read_text_File (to_String (shader_Snippets (snippet_Id)));
+         end if;
+      end combine_Snippets;
+
+   begin
+      return   combine_Snippets
+             & (1 => C.char (ada.Characters.Latin_1.NUL));
+   end to_C_char_array;
+
+
+
+
+   procedure create_Shader (Self : in out Item;   Kind   : in Shader.Kind;
+                                                  Source : in C.char_array)
    is
       use GL.Pointers,
           C.Strings;
 
-      the_Source       : aliased  C.char_array    := read_text_File (source_Filename);
+      use type interfaces.C.char_array;
-      the_Source_ptr   : aliased
+
-                         constant chars_ptr       := to_chars_ptr (the_Source'unchecked_Access);
+      the_Source       : aliased          C.char_array    := Source;
-      the_Source_Array : aliased  chars_ptr_array := [1 => the_Source_ptr];
+      the_Source_ptr   : aliased constant chars_ptr       := to_chars_ptr (the_Source'unchecked_Access);
+      the_Source_Array : aliased          chars_ptr_array := [1 => the_Source_ptr];
+
    begin
       Tasks.check;
 
+      --  for i in the_Source'Range
+      --  loop
+      --     put (Character (the_Source (i)));
+      --  end loop;
+
+
       Self.Kind := Kind;
 
       if Kind = Vertex
@@ -58,7 +109,7 @@ is
       Errors.log;
 
       declare
-         use type C.int;
+         use interfaces.C;
          Status : aliased gl.glInt;
       begin
          glGetShaderiv (self.gl_Shader,
@@ -70,14 +121,37 @@ is
                compile_Log : constant String := Self.shader_info_Log;
             begin
                Self.destroy;
-               raise Error with "'" & source_Filename & "' compilation failed ~ " & compile_Log;
+               raise Error with "'" & to_Ada (the_Source) & "' compilation failed ~ " & compile_Log;
             end;
          end if;
       end;
+   end create_Shader;
+
+
+
+
+   procedure define (Self : in out Item;   Kind            : in Shader.Kind;
+                                           shader_Filename : in String)
+   is
+      the_Source : aliased constant C.char_array := to_C_char_array (shader_Filename);
+   begin
+      create_Shader (Self, Kind, the_Source);
    end define;
 
 
 
+
+   procedure define (Self : in out Item;   Kind            : in Shader.Kind;
+                                           shader_Snippets : in asset_Names)
+   is
+      the_Source : aliased constant C.char_array := to_C_char_array (shader_Snippets);
+   begin
+      create_Shader (Self, Kind, the_Source);
+   end define;
+
+
+
+
    procedure destroy (Self : in out Item)
    is
    begin
@@ -86,6 +160,7 @@ is
    end destroy;
 
 
+
    --------------
    --  Attributes
    --
@@ -123,6 +198,8 @@ is
    end shader_info_Log;
 
 
+
+
    ----------
    --  Privvy
    --
@@ -134,44 +211,55 @@ is
    end gl_Shader;
 
 
+
+
    -----------
    --  Utility
    --
-   NL : constant String := "" & ada.characters.latin_1.LF;
-
 
    function read_text_File (Filename : in String) return C.char_array
    is
       use ada.Text_IO,
           ada.Strings.unbounded;
 
+      use type interfaces.C.size_t;
+
+      NL        : constant String      := "" & ada.characters.latin_1.LF;
       the_File  : ada.Text_IO.File_type;
       Pad       : unbounded_String;
 
    begin
-      open (the_File, in_File, Filename);
+      if Filename = ""
+      then
+         return C.char_array' (1 .. 0 => <>);
+      else
+         open (the_File, in_File, Filename);
 
-      while not end_of_File (the_File)
+         while not end_of_File (the_File)
-      loop
-         append (Pad, get_Line (the_File) & NL);
-      end loop;
-
-      close (the_File);
-
-      declare
-         use type Interfaces.C.size_t;
-
-         the_Data : C.char_array (1 .. C.size_t (Length (Pad)) + 1);
-      begin
-         for i in 1 .. the_Data'Last - 1
          loop
-            the_Data (i) := C.char (Element (Pad, Integer (i)));
+            append (Pad, get_Line (the_File) & NL);
          end loop;
 
-         the_Data (the_Data'Last) := C.char'Val (0);
+         close (the_File);
 
-         return the_Data;
+         if Length (Pad) = 0
-      end;
+         then
+            return C.char_array' (1 .. 0 => <>);
+         else
+            declare
+               the_Data : C.char_array (0 .. C.size_t (Length (Pad) - 1));
+            begin
+               for i in the_Data'Range
+               loop
+                  the_Data (i) := C.char (Element (Pad, Integer (i) + 1));
+               end loop;
+
+               --  the_Data (the_Data'Last) := C.char'Val (0);
+
+               return the_Data;
+            end;
+         end if;
+      end if;
 
    exception
       when ada.IO_Exceptions.name_Error =>

3-mid/opengl/source/lean/shader/opengl-shader.ads

@@ -19,7 +19,10 @@ is
    --  Forge
    --
    procedure define  (Self : in out Item;   Kind            : in Shader.Kind;
-                                            source_Filename : in String);
+                                            shader_Filename : in String);
+
+   procedure define  (Self : in out Item;   Kind            : in Shader.Kind;
+                                            shader_Snippets : in asset_Names);
    procedure destroy (Self : in out Item);