more typesafe uniforms

src/assets/positionable_object.rs

@@ -3,6 +3,7 @@ use gl::types::*;
 use nalgebra::{Vector4, Rotation3, Translation3, Matrix4, Vector3};
 use std::ffi::CString;
 use std::os::raw::c_char;
+use crate::opengl::wrapper::uniform::Uniform;
 
 pub struct PositionableObject {
   pub renderable_object: RenderableObject,
@@ -63,8 +64,7 @@ impl PositionableObject {
     transformation.as_ptr()
   }*/
 
-  pub fn draw(&self, model_view_uniform_id: GLint) {
-    unsafe {
+  pub fn draw(&self, model_transform_id: Uniform) {
       //let name : CString = CString::new("view").expect("string is correct");
       //let name_ptr : *const c_char = name.as_ptr() as *const c_char;
 
@@ -83,7 +83,8 @@ impl PositionableObject {
 
       let mat_ptr = transformation.as_ptr();
 
-      gl::UniformMatrix4fv(model_view_uniform_id, 1, gl::FALSE, mat_ptr);
+    unsafe {
+      gl::UniformMatrix4fv(model_transform_id.id(), 1, gl::FALSE, mat_ptr);
     }
 
     self.renderable_object.draw();

src/opengl/wrapper/mod.rs

@@ -1,4 +1,5 @@
 pub mod buffer;
 pub mod other_misc_wrapper;
 pub mod texture;
+pub mod uniform;
 pub mod vertex_array;

src/opengl/wrapper/uniform.rs

@@ -0,0 +1,27 @@
+use anyhow::Result as AnyhowResult;
+use gl::types::*;
+use std::os::raw::c_char;
+
+/// A typesafe handle on uniform IDs with convenience methods.
+#[derive(Clone, Debug, Copy)]
+pub struct Uniform {
+  id: GLint,
+}
+
+impl Uniform {
+  pub fn lookup(opengl_program_id: GLuint, identifier: *const c_char) -> AnyhowResult<Self> {
+    let mut loc = -1;
+
+    unsafe {
+      loc = gl::GetUniformLocation(opengl_program_id, identifier);
+    }
+
+    Ok(Self {
+      id: loc,
+    })
+  }
+
+  pub fn id(&self) -> GLint {
+    self.id
+  }
+}

src/point_cloud/point_cloud_renderer.rs

@@ -34,6 +34,7 @@ use std::time::{SystemTime, UNIX_EPOCH};
 use tobj::load_obj;
 use crate::assets::positionable_object::PositionableObject;
 use cgmath::{Matrix4, SquareMatrix, Matrix};
+use crate::opengl::wrapper::uniform::Uniform;
 
 pub type Result<T> = std::result::Result<T, PointCloudRendererError>;
 
@@ -109,7 +110,7 @@ pub struct PointCloudRenderer {
   projection_index: GLint,
 
   /// Uniform location in the shader program.
-  model_view_index: GLint,
+  model_transform_id: Uniform,
 
   /// Uniform location in the shader program.
   enable_shading_index: GLint,
@@ -222,7 +223,6 @@ impl PointCloudRenderer {
 
     let mut view_index = 0;
     let mut projection_index = 0;
-    let mut model_view_index = 0;
     let mut enable_shading_index = 0;
 
     unsafe {
@@ -232,13 +232,14 @@ impl PointCloudRenderer {
       // FIXME: THe 'view' and 'projection' uniforms are not binding for some reason.
       view_index = gl::GetUniformLocation(program_id, VIEW_PTR);
       projection_index = gl::GetUniformLocation(program_id, PROJECTION_PTR);
-      model_view_index = gl::GetUniformLocation(program_id, MODEL_VIEW_PTR);
       enable_shading_index = gl::GetUniformLocation(program_id, ENABLE_SHADING_PTR);
       // TODO: This is hardcoded to 2
       point_cloud_texture_indices.push(gl::GetUniformLocation(program_id, POINT_CLOUD_0_PTR));
       point_cloud_texture_indices.push(gl::GetUniformLocation(program_id, POINT_CLOUD_1_PTR));
     }
 
+    let model_transform = Uniform::lookup(program_id, MODEL_VIEW_PTR).unwrap();
+
     let color_vertex_attribute_location = unsafe {
       let location = gl::GetAttribLocation(program_id, COLOR_LOCATION_PTR);
 
@@ -292,7 +293,7 @@ impl PointCloudRenderer {
       enable_shading: false,
       view_index,
       projection_index,
-      model_view_index,
+      model_transform_id: model_transform,
       enable_shading_index,
       point_cloud_texture_indices,
       vertex_array_objects: Vec::with_capacity(num_cameras),
@@ -503,7 +504,7 @@ impl PointCloudRenderer {
 
       if use_default_model_view {
         let typed_model_view = self.default_model_view_matrix.as_ptr() as *const GLfloat;
-        gl::UniformMatrix4fv(self.model_view_index, 1, gl::FALSE, typed_model_view);
+        gl::UniformMatrix4fv(self.model_transform_id.id(), 1, gl::FALSE, typed_model_view);
       }
 
       // Update render settings in shader
@@ -524,7 +525,7 @@ impl PointCloudRenderer {
       gl::BindVertexArray(0);
 
       if let Some(ref renderable) = self.renderable_object {
-        renderable.draw(self.model_view_index);
+        renderable.draw(self.model_transform_id);
       }
 
       gl_get_error()