From 52d7eb5eab6180cf45fb4a3b5a77b9fbe6770c6c Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Mon, 7 Dec 2020 15:40:11 -0500
Subject: [PATCH] Allow passing shaders and attribute locations to Program
 constructor.

---
 src/gltk/program.d    | 29 +++++++++++++++++++++++++----
 src/jes/gui/package.d |  6 +-----
 2 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/src/gltk/program.d b/src/gltk/program.d
index 14d9879..4c096d5 100644
--- a/src/gltk/program.d
+++ b/src/gltk/program.d
@@ -7,13 +7,17 @@ class Program
 {
     private GLuint m_id;
 
-    this()
+    this(Args...)(Args args)
     {
         m_id = glCreateProgram();
         if (m_id == 0u)
         {
             throw new Exception("Failed to allocate an OpenGL program");
         }
+        static if (args.length != 0u)
+        {
+            build(args);
+        }
     }
 
     ~this()
@@ -26,7 +30,7 @@ class Program
         glAttachShader(m_id, shader.id);
     }
 
-    void bind_attrib_location(uint index, string name)
+    void bind_attrib_location(string name, uint index) const
     {
         glBindAttribLocation(m_id, index, name.toStringz());
     }
@@ -54,12 +58,12 @@ class Program
         }
     }
 
-    GLint get_uniform_location(string uniform_name)
+    GLint get_uniform_location(string uniform_name) const
     {
         return glGetUniformLocation(m_id, uniform_name.toStringz());
     }
 
-    @property GLuint id()
+    @property GLuint id() const
     {
         return m_id;
     }
@@ -68,4 +72,21 @@ class Program
     {
         glUseProgram(m_id);
     }
+
+    private void build(Args...)(Shader s, Args args) const
+    {
+        attach_shader(s);
+        build(args);
+    }
+
+    private void build(Args...)(string attrib_name, uint index, Args args) const
+    {
+        bind_attrib_location(attrib_name, index);
+        build(args);
+    }
+
+    private void build() const
+    {
+        link();
+    }
 }
diff --git a/src/jes/gui/package.d b/src/jes/gui/package.d
index 3ddd848..b777cfe 100644
--- a/src/jes/gui/package.d
+++ b/src/jes/gui/package.d
@@ -47,11 +47,7 @@ class Gui
             v_shader.set_source_from_file("share/jes/shaders/text.v.glsl");
             auto f_shader = new gltk.Shader(GL_FRAGMENT_SHADER);
             f_shader.set_source_from_file("share/jes/shaders/text.f.glsl");
-            m_text_program = new gltk.Program();
-            m_text_program.attach_shader(v_shader);
-            m_text_program.attach_shader(f_shader);
-            m_text_program.bind_attrib_location(0u, "coords");
-            m_text_program.link();
+            m_text_program = new gltk.Program(v_shader, f_shader, "coords", 0);
             m_viewport_size = m_text_program.get_uniform_location("viewport_size");
             m_texture = m_text_program.get_uniform_location("texture");
             m_color = m_text_program.get_uniform_location("color");