From 1026a2c791b9219a343cf09c2dcac80cb4930229 Mon Sep 17 00:00:00 2001
From: David Allemang <allemang.d@gmail.com>
Date: Sun, 8 Sep 2019 23:47:07 -0400
Subject: [PATCH] move shaders into separate files

---
 cosets/CMakeLists.txt           |  7 ++++++
 cosets/src/main.cpp             | 41 ++++++++-------------------------
 cosets/src/shaders/main.fs.glsl | 13 +++++++++++
 cosets/src/shaders/main.vs.glsl | 14 +++++++++++
 cosets/src/util/files.hpp       | 19 +++++++++++++++
 cosets/src/util/shader.hpp      |  7 ++++++
 6 files changed, 69 insertions(+), 32 deletions(-)
 create mode 100644 cosets/src/shaders/main.fs.glsl
 create mode 100644 cosets/src/shaders/main.vs.glsl
 create mode 100644 cosets/src/util/files.hpp

diff --git a/cosets/CMakeLists.txt b/cosets/CMakeLists.txt
index 79a4510..dfa29e2 100644
--- a/cosets/CMakeLists.txt
+++ b/cosets/CMakeLists.txt
@@ -8,3 +8,10 @@ target_link_libraries(${PROJECT_NAME}
 
 target_include_directories(${PROJECT_NAME}
         PRIVATE include)
+
+add_custom_command(
+    TARGET cosets POST_BUILD
+    COMMAND ${CMAKE_COMMAND} -E copy_directory
+            ${CMAKE_CURRENT_SOURCE_DIR}/src/shaders
+            ${CMAKE_CURRENT_BINARY_DIR}/shaders
+)
diff --git a/cosets/src/main.cpp b/cosets/src/main.cpp
index eedb1fa..8531459 100644
--- a/cosets/src/main.cpp
+++ b/cosets/src/main.cpp
@@ -17,38 +17,15 @@ class CosetsWindow : public Window {
 
 public:
    void init() override {
-      auto vs = build_shader(GL_VERTEX_SHADER, "vertex",
-         "#version 400\n"
-         ""
-         "uniform mat4 proj;"
-         ""
-         "in vec4 pos;"
-         "out vec4 v;"
-         ""
-         "void main(){"
-         "  v = pos;"
-         ""
-         "  /* stereographic projection */"
-         "  vec4 vert = vec4(pos.xyz / (1 - pos.w), 1);"
-         "  gl_Position = proj * vert;"
-         "}");
+      auto vs = build_shader_file(
+         GL_VERTEX_SHADER,
+         "vertex",
+         "shaders/main.vs.glsl");
 
-      auto fs = build_shader(GL_FRAGMENT_SHADER, "fragment",
-         "#version 400\n"
-         ""
-         "in vec4 v;"
-         ""
-         "vec3 hsv2rgb(vec3 c)\n"
-         "{\n"
-         "    vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);\n"
-         "    vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);\n"
-         "    return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);\n"
-         "}"
-         ""
-         "void main(){"
-         "  gl_FragColor = vec4(hsv2rgb(vec3(v.w, 1, 1)), 0);"
-         "}"
-      );
+      auto fs = build_shader_file(
+         GL_FRAGMENT_SHADER,
+         "fragment",
+         "shaders/main.fs.glsl");
 
       program = build_program("main", vs, fs);
 
@@ -123,4 +100,4 @@ int main(int argc, char *argv[]) {
 
    glfwTerminate();
    return EXIT_SUCCESS;
-}
\ No newline at end of file
+}
diff --git a/cosets/src/shaders/main.fs.glsl b/cosets/src/shaders/main.fs.glsl
new file mode 100644
index 0000000..25a8486
--- /dev/null
+++ b/cosets/src/shaders/main.fs.glsl
@@ -0,0 +1,13 @@
+#version 400
+
+in vec4 v;
+
+vec3 hsv2rgb(vec3 c) {
+    vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
+    vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
+    return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
+}
+
+void main(){
+  gl_FragColor = vec4(hsv2rgb(vec3(v.w, 1, 1)), 0);
+}
diff --git a/cosets/src/shaders/main.vs.glsl b/cosets/src/shaders/main.vs.glsl
new file mode 100644
index 0000000..01f2172
--- /dev/null
+++ b/cosets/src/shaders/main.vs.glsl
@@ -0,0 +1,14 @@
+#version 400
+
+uniform mat4 proj;
+
+in vec4 pos;
+out vec4 v;
+
+void main(){
+  v = pos;
+
+  /* stereographic projection */
+  vec4 vert = vec4(pos.xyz / (1 - pos.w), 1);
+  gl_Position = proj * vert;
+}
diff --git a/cosets/src/util/files.hpp b/cosets/src/util/files.hpp
new file mode 100644
index 0000000..03b3541
--- /dev/null
+++ b/cosets/src/util/files.hpp
@@ -0,0 +1,19 @@
+#pragma once
+
+#include <fstream>
+#include <string>
+#include <streambuf>
+
+std::string read_all_text(const std::string &file) {
+   std::ifstream f(file);
+   std::string text;
+
+   f.seekg(0, std::ios::end);
+   text.reserve(f.tellg());
+   f.seekg(0, std::ios::beg);
+
+   text.assign((std::istreambuf_iterator<char>(f)),
+      std::istreambuf_iterator<char>());
+
+   return text;
+}
diff --git a/cosets/src/util/shader.hpp b/cosets/src/util/shader.hpp
index 7db357c..cfa2d0c 100644
--- a/cosets/src/util/shader.hpp
+++ b/cosets/src/util/shader.hpp
@@ -5,6 +5,8 @@
 #include <cstdio>
 #include <cstdlib>
 
+#include "files.hpp"
+
 GLint build_shader(GLenum type, const std::string &name, const std::string &src) {
    const char *c_str = src.c_str();
 
@@ -28,6 +30,11 @@ GLint build_shader(GLenum type, const std::string &name, const std::string &src)
    return s;
 }
 
+GLint build_shader_file(GLenum type, const std::string &name, const std::string &file) {
+   std::string src = read_all_text(file);
+   return build_shader(type, name, src);
+}
+
 GLint build_program(const std::string &name, GLint vs, GLint fs) {
    GLint p = glCreateProgram();
    glAttachShader(p, vs);