feat(engine): add default shaders when creating shader program

1 files changed, 31 insertions, 3 deletions

diff --git a/engine/src/shader.rs b/engine/src/shader.rs
index a0066f1..89f7b7c 100644
--- a/engine/src/shader.rs
+++ b/engine/src/shader.rs
@@ -7,6 +7,11 @@ use ecs::Component;
 
 use crate::shader_preprocessor::{Error as ShaderPreprocessorError, ShaderPreprocessor};
 
+const VERTEX_SHADER_FILE: &str = "vertex.glsl";
+const FRAGMENT_SHADER_FILE: &str = "fragment.glsl";
+
+const SHADER_DIR: &str = "engine";
+
 /// Shader program
 #[derive(Debug, Clone, PartialEq, Eq, Hash, Default, Component)]
 pub struct Program
@@ -16,10 +21,33 @@ pub struct Program
 
 impl Program
 {
-    #[must_use]
-    pub fn new() -> Self
+    /// Creates a new shader program with the default shaders.
+    ///
+    /// # Errors
+    /// Returns `Err` if:
+    /// - Reading a default shader file Fails
+    /// - Preprocessing a shader fails.
+    pub fn new() -> Result<Self, Error>
     {
-        Self { shaders: Vec::new() }
+        let mut program = Self { shaders: Vec::new() };
+
+        program.push_shader(
+            Shader::read_shader_file(
+                Kind::Vertex,
+                &Path::new(SHADER_DIR).join(VERTEX_SHADER_FILE),
+            )?
+            .preprocess()?,
+        );
+
+        program.push_shader(
+            Shader::read_shader_file(
+                Kind::Fragment,
+                &Path::new(SHADER_DIR).join(FRAGMENT_SHADER_FILE),
+            )?
+            .preprocess()?,
+        );
+
+        Ok(program)
     }
 
     pub fn push_shader(&mut self, shader: Shader)