From 9528025a238f12ccfd257aaddf4d285ae584806b Mon Sep 17 00:00:00 2001
From: Erin <sylphofelectricity@gmail.com>
Date: Sun, 20 Aug 2017 17:09:51 -0500
Subject: [PATCH] textium: start work on a gl/glium renderer

---
 textium/src/lib.rs                        |  1 +
 textium/src/renderer/gl_renderer_140.frag | 17 ++++++++++++++++
 textium/src/renderer/gl_renderer_140.vert | 12 +++++++++++
 textium/src/renderer/glium_renderer.rs    | 34 +++++++++++++++++++++++++++++++
 textium/src/renderer/mod.rs               |  3 +++
 5 files changed, 67 insertions(+)
 create mode 100644 textium/src/renderer/gl_renderer_140.frag
 create mode 100644 textium/src/renderer/gl_renderer_140.vert
 create mode 100644 textium/src/renderer/glium_renderer.rs
 create mode 100644 textium/src/renderer/mod.rs

diff --git a/textium/src/lib.rs b/textium/src/lib.rs
index 83b9740..c99d35f 100644
--- a/textium/src/lib.rs
+++ b/textium/src/lib.rs
@@ -15,6 +15,7 @@ pub mod geometry;
 pub mod rasterizer;
 pub mod packer;
 pub mod cache;
+pub mod renderer;
 
 use std::collections::HashMap;
 use std::hash::{Hash, Hasher};
diff --git a/textium/src/renderer/gl_renderer_140.frag b/textium/src/renderer/gl_renderer_140.frag
new file mode 100644
index 0000000..fb00b9d
--- /dev/null
+++ b/textium/src/renderer/gl_renderer_140.frag
@@ -0,0 +1,17 @@
+#version 140
+
+in vec2 v_tex_coord;
+
+out vec4 frag_color;
+
+uniform sampler2D tex;
+
+void main() {
+	vec4 c = vec4(0, 0, 0, texture(tex, v_tex_coord));
+
+	if (c.a <= 0.01) {
+		discard;
+	} else {
+		frag_color = c;
+	}
+}
diff --git a/textium/src/renderer/gl_renderer_140.vert b/textium/src/renderer/gl_renderer_140.vert
new file mode 100644
index 0000000..f97643d
--- /dev/null
+++ b/textium/src/renderer/gl_renderer_140.vert
@@ -0,0 +1,12 @@
+#version 140
+
+in vec2 position;
+in vec2 tex_coord;
+
+out vec2 v_tex_coord;
+
+void main() {
+	gl_Position = vec4(position, 0.0, 1.0);
+
+	v_tex_coord = tex_coord;
+}
diff --git a/textium/src/renderer/glium_renderer.rs b/textium/src/renderer/glium_renderer.rs
new file mode 100644
index 0000000..6f65e7e
--- /dev/null
+++ b/textium/src/renderer/glium_renderer.rs
@@ -0,0 +1,34 @@
+use glium::Program;
+use glium::backend::Facade;
+
+#[derive(Copy, Clone, Debug)]
+struct Vertex {
+    position: [u32; 2],
+    tex_coords: [u32; 2],
+}
+
+implement_vertex!(Vertex, position, tex_coords);
+
+static SHADER_FRAG_140: &'static str = include_str!("gl_renderer_140.frag");
+static SHADER_VERT_140: &'static str = include_str!("gl_renderer_140.vert");
+
+pub struct TextRenderer {
+    gl_program: Program,
+}
+
+impl TextRenderer {
+    pub fn new<F>(display: &F) -> TextRenderer where F: Facade {
+        let program = program!(display,
+            140 => {
+                vertex: SHADER_VERT_140,
+                fragment: SHADER_FRAG_140,
+            },
+        ).expect("textium: could not compile glium renderer shaders");
+
+        TextRenderer {
+            gl_program: program,
+        }
+    }
+
+    // pub fn draw(text: RenderableText)
+}
diff --git a/textium/src/renderer/mod.rs b/textium/src/renderer/mod.rs
new file mode 100644
index 0000000..84ae47f
--- /dev/null
+++ b/textium/src/renderer/mod.rs
@@ -0,0 +1,3 @@
+mod glium_renderer;
+
+pub use self::glium_renderer::TextRenderer as GliumRenderer;