opengl.light: Add 'Strength' to lights.

3-mid/opengl/assets/shader/lighting-frag.snippet

@@ -4,6 +4,7 @@
 struct light
 {
    vec4    Site;
+   float   Strength;
    vec3    Color;
    float   Attenuation;
    float   ambient_Coefficient;
@@ -67,7 +68,7 @@ apply_Light (light   Light,
 
     // Abmbient.
     //
-    vec3    lit_surface_Color    = surface_Color             * Light.Color;
+    vec3    lit_surface_Color    = surface_Color             * Light.Color * Light.Strength;
     vec3    Ambient              = Light.ambient_Coefficient * lit_surface_Color;
 
 

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

@@ -58,6 +58,22 @@ is
    end Site_is;
 
 
+
+   function Strength (Self : in Item)     return Intensity
+   is
+   begin
+      return Self.Strength;
+   end Strength;
+
+
+   procedure Strength_is (Self : in out Item;   Now : in Intensity)
+   is
+   begin
+      Self.Strength := Now;
+   end Strength_is;
+
+
+
    function Color (Self : in Item) return openGL.Color
    is
    begin

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

@@ -16,6 +16,7 @@ is
    --
    type Id_t      is new Natural;
    type Kind_t    is (Diffuse, Direct);
+   type Intensity is digits 5 range 0.0 .. 10.0;
 
    null_Id : constant Id_t;
 
@@ -31,6 +32,9 @@ is
    function  Site        (Self : in     Item)     return openGL.Site;
    procedure Site_is     (Self : in out Item;   Now : in openGL.Site);
 
+   function  Strength    (Self : in     Item)     return Intensity;
+   procedure Strength_is (Self : in out Item;   Now : in Intensity);
+
    function  Color               (Self : in     Item) return Color;
    function  Attenuation         (Self : in     Item) return Real;
    function  ambient_Coefficient (Self : in     Item) return Real;
@@ -56,6 +60,7 @@ private
          On   : Boolean      := True;
          Site : openGL.Site  := [0.0, 0.0, 1.0];     -- The GL default.
 
+         Strength            : Intensity    := 1.0;
          Color               : openGL.Color := Palette.White;
          Attenuation         : Real         :=  0.1;
          ambient_Coefficient : Real         :=  0.1;

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

@@ -1,12 +1,6 @@
 with
      openGL.Conversions,
-     GL.lean,
+     ada.Strings.fixed;
-     GL.Binding,
-     GL.Pointers,
-     ada.Strings.fixed,
-     Interfaces.C.Strings;
-
-with ada.text_io; use ada.text_io;
 
 
 package body openGL.Program.lit
@@ -80,6 +74,7 @@ is
             end light_Name;
 
             site_Uniform                : constant Variable.uniform.vec4  := Self.uniform_Variable (light_Name & ".Site");
+            strength_Uniform            : constant Variable.uniform.float := Self.uniform_Variable (light_Name & ".Strength");
             color_Uniform               : constant Variable.uniform.vec3  := Self.uniform_Variable (light_Name & ".Color");
             attenuation_Uniform         : constant Variable.uniform.float := Self.uniform_Variable (light_Name & ".Attenuation");
             ambient_coefficient_Uniform : constant Variable.uniform.float := Self.uniform_Variable (light_Name & ".ambient_Coefficient");
@@ -93,6 +88,7 @@ is
             end case;
 
             color_Uniform              .Value_is (to_Vector_3 (Light.Color));
+            strength_Uniform           .Value_is (Real        (Light.Strength));
             attenuation_Uniform        .Value_is (             Light.Attenuation);
             ambient_coefficient_Uniform.Value_is (             Light.ambient_Coefficient);
             cone_angle_Uniform         .Value_is (Real        (Light.cone_Angle));