From 54355fccd0ae44c15d11b6740c7f21cfc708fc42 Mon Sep 17 00:00:00 2001
From: falsycat <me@falsy.cat>
Date: Sun, 13 Oct 2019 00:00:00 +0000
Subject: [PATCH] [add] Added TextProgram.

---
 src/sj/ProgramSet.d  |   2 +
 src/sj/TextProgram.d | 105 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 107 insertions(+)
 create mode 100644 src/sj/TextProgram.d

diff --git a/src/sj/ProgramSet.d b/src/sj/ProgramSet.d
index 6d09718..f1da5ff 100644
--- a/src/sj/ProgramSet.d
+++ b/src/sj/ProgramSet.d
@@ -7,6 +7,7 @@ import std.meta,
 static import sjplayer = sjplayer.ProgramSet;
 
 import sj.CubeProgram,
+       sj.TextProgram,
        sj.TitleTextProgram;
 
 ///
@@ -14,6 +15,7 @@ class ProgramSet {
  public:
   alias Programs = Tuple!(
       CubeProgram,
+      TextProgram,
       TitleTextProgram,
     );
 
diff --git a/src/sj/TextProgram.d b/src/sj/TextProgram.d
new file mode 100644
index 0000000..270c2c0
--- /dev/null
+++ b/src/sj/TextProgram.d
@@ -0,0 +1,105 @@
+/// License: MIT
+module sj.TextProgram;
+
+import gl4d;
+
+///
+class TextProgram {
+ public:
+  ///
+  static struct Vertex {
+   public:
+    ///
+    align(1) vec3 pos;
+    ///
+    align(1) vec2 uv;
+  }
+
+  ///
+  enum ShaderHeader = "#version 330 core
+#extension GL_ARB_explicit_uniform_location : enable";
+
+  ///
+  enum VertexShaderSrc = ShaderHeader ~ q{
+    layout(location = 0) uniform mat4 P;
+    layout(location = 1) uniform mat4 V;
+    layout(location = 2) uniform mat4 M;
+
+    layout(location = 0) in vec3 vert;
+    layout(location = 1) in vec2 uv;
+
+    out vec2 uv_;
+
+    void main() {
+      uv_ = uv;
+      gl_Position = P * V * M * vec4(vert, 1);
+    }
+  };
+  ///
+  enum FragmentShaderSrc = ShaderHeader ~ q{
+    layout(location = 3) uniform sampler2D tex;
+
+    in vec2 uv_;
+
+    out vec4 pixel_;
+
+    void main() {
+      pixel_ = texture(tex, uv_);
+    }
+  };
+
+  ///
+  this() {
+    ProgramLinker linker;
+    linker.vertex   = VertexShader.Compile(VertexShaderSrc);
+    linker.fragment = FragmentShader.Compile(FragmentShaderSrc);
+    program_ = linker.Link();
+    program_.Validate();
+
+    sampler_ = Sampler.Create();
+    SamplerConfigurer configurer;
+    with (configurer) {
+      filterMin = GL_LINEAR;
+      filterMag = GL_LINEAR;
+      Configure(sampler_);
+    }
+  }
+
+  ///
+  void SetupVertexArray(ref VertexArrayRef vao, ref ArrayBufferRef vertices) {
+    vao.Bind();
+    VertexArrayAttacher attacher;
+    with (attacher) {
+      index     = 0;
+      type      = GL_FLOAT;
+      offset    = 0;
+      stride    = Vertex.sizeof;
+      dimension = 3;
+      Attach(vao, vertices);
+
+      index     = 1;
+      type      = GL_FLOAT;
+      offset    = vec3.sizeof;
+      stride    = Vertex.sizeof;
+      dimension = 2;
+      Attach(vao, vertices);
+    }
+  }
+
+  ///
+  void Use(mat4 proj, mat4 view, mat4 model, ref Texture2DRef tex) {
+    tex.BindToUnit(GL_TEXTURE0);
+    sampler_.Bind(0);
+
+    program_.Use();
+    program_.uniform!0 = proj;
+    program_.uniform!1 = view;
+    program_.uniform!2 = model;
+    program_.uniform!3 = 0;
+  }
+
+ private:
+  ProgramRef program_;
+
+  SamplerRef sampler_;
+}