panning in a plane

resources/shaders/plane/shader.frag

@@ -0,0 +1,16 @@
+#version 330 core
+
+in vec2 v_texcoord;
+
+out vec4 frag_color;
+
+uniform sampler2D tex;
+
+void main()
+{
+    // Sample the texture using the texture coordinates
+    vec4 tex_color = texture(tex, v_texcoord);
+
+    // Output the final color
+    frag_color = tex_color;
+}

resources/shaders/plane/shader.vert

@@ -0,0 +1,24 @@
+#version 330 core
+
+layout(location = 0) in vec3 position;
+layout(location = 1) in vec2 texcoord;
+
+out vec2 v_texcoord;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+uniform float tile_size;
+uniform float scroll_speed;
+
+uniform vec3 camera_position;
+void main()
+{
+    // Apply the model, view, and projection matrices
+    gl_Position = projection * view * model * vec4(position, 1.0);
+
+    // Calculate the texture coordinate offset based on the camera position
+    vec2 offset = (camera_position.xz - position.xz) / tile_size;
+    offset += scroll_speed * vec2(0, 1) * -(gl_Position.w / projection[1][1]);
+    v_texcoord = texcoord + offset;
+}

src/camera.rs

@@ -68,6 +68,10 @@ impl Camera {
         Matrix4::look_at(self.Position, self.Position + self.Front, self.Up)
     }
 
+    pub fn follow(&mut self, pos: Vector3)
+        {
+            self.Position = Point3::new(0.0, 0.55, 1.0) + pos;
+        }
     /// Processes input received from any keyboard-like input system. Accepts input parameter in the form of camera defined ENUM (to abstract it from windowing systems)
     pub fn ProcessKeyboard(&mut self, direction: Camera_Movement, deltaTime: f32) {
         let velocity = self.MovementSpeed * deltaTime;

src/main.rs

@@ -88,7 +88,7 @@ fn main() {
 
     let mut State = gameState::Playing;
 
-    let mut scene = Scene::new(gl);
+      let mut scene = Scene::new(gl);
 
     println!("entering main loop");
 

src/model.rs

@@ -110,7 +110,7 @@ impl Model {
     }
 }
 
-unsafe fn TextureFromFile(path: &str, directory: &str, gl: Arc<glow::Context>) -> glow::NativeTexture {
+pub unsafe fn TextureFromFile(path: &str, directory: &str, gl: Arc<glow::Context>) -> glow::NativeTexture {
     let filename = format!("{}/{}", directory, path);
 
     let mut textureID = gl.create_texture().unwrap();

src/scene.rs

@@ -40,7 +40,8 @@ pub struct Scene {
     shaders: Vec<Rc<shader>>,
     time: std::time::Instant,
     DebugMode: bool,
-    input: objects::Input
+    input: objects::Input,
+    plane: objects::plane
 }
 
 impl Scene{
@@ -49,6 +50,7 @@ impl Scene{
             let Car = objects::Player::new(Arc::clone(&gl));
 
             let shader = Rc::new(shader::new("model", Arc::clone(&gl)));
+            let planeShader = Rc::new(shader::new("plane", Arc::clone(&gl)));
 
             let time = std::time::Instant::now();
 
@@ -57,6 +59,7 @@ impl Scene{
                 Pitch: -20.0,
                 ..Camera::default()
             };
+            let plane = objects::plane::new(Arc::clone(&gl));
 
             let debug = Debug::new(gl.clone());
             Scene{
@@ -64,15 +67,20 @@ impl Scene{
                 Car,
                 camera,
                 debug,
-                shaders: vec![shader],
+                shaders: vec![shader, planeShader],
                 time,
                 DebugMode: false,
-                input: objects::Input::default()
+                input: objects::Input::default(),
+                plane
             }
         }
 
     pub fn update(&mut self ,events_loop: &mut sdl2::EventPump, window: &sdl2::video::Window) -> SceneEnum
         {
+
+
+
+
             let mut ret = SceneEnum::Resume;
 
             unsafe {
@@ -81,6 +89,10 @@ impl Scene{
             }
 
 
+            self.camera.follow(self.Car.Transform.Position);
+            self.plane.draw(&self.shaders[1], &self.camera);
+            self.Car.update(&self.input);
+            self.Car.Draw(&self.shaders[0], &self.camera);
             if self.DebugMode{
                 self.handleDebug(events_loop, window, &mut ret)
                           }
@@ -133,8 +145,6 @@ impl Scene{
 
             }
 
-            self.Car.update(&self.input);
-            self.Car.Draw(&self.shaders[0], &self.camera);
                 ret
         }
 

src/scene/objects.rs

@@ -2,10 +2,11 @@
 const SCR_WIDTH: u32 = 1600;
 const SCR_HEIGHT: u32 = 900;
 
-use cgmath::{Vector3, Quaternion, Rotation3};
+use cgmath::{Vector3, Quaternion, Rotation3, Deg, perspective, Matrix4};
 use cgmath::prelude::*;
 use crate::model::Model;
 use crate::camera::Camera;
+use glow::HasContext;
 
 pub struct Input {
     pub Accel: bool,
@@ -117,3 +118,92 @@ impl Player {
             self.Model.Draw(shader);
         }
 }
+
+pub struct plane {
+    pub texture: glow::NativeTexture,
+    pub VAO: glow::VertexArray,
+
+    VBO: glow::Buffer,
+    EBO: glow::Buffer,
+}
+
+impl plane {
+    pub fn new(gl: std::sync::Arc<glow::Context>) -> plane
+    {
+        let vertices: [f32; 20] = [
+            10.5, 10.5, 0.0, 1.0, 1.0,
+            10.5, -10.5, 0.0, 1.0, 0.0,
+            -10.5, -10.5, 0.0, 0.0, 0.0,
+            -10.5, 10.5, 0.0, 0.0, 1.0
+        ];
+        let indices: [u32; 6] = [
+            0, 1, 3,
+            1, 2, 3
+        ];
+        unsafe {
+            let VAO = gl.create_vertex_array().unwrap();
+            let VBO = gl.create_buffer().unwrap();
+            let EBO = gl.create_buffer().unwrap();
+
+            gl.bind_vertex_array(Some(VAO));
+
+            gl.bind_buffer(glow::ARRAY_BUFFER, Some(VBO));
+            let data = core::slice::from_raw_parts(
+                vertices.as_ptr() as *const u8,
+                vertices.len() * core::mem::size_of::<f32>(),
+            );
+            gl.named_buffer_data_u8_slice(VBO, data, glow::STATIC_DRAW);
+
+            gl.bind_buffer(glow::ELEMENT_ARRAY_BUFFER, Some(EBO));
+            let data = core::slice::from_raw_parts(
+                indices.as_ptr() as *const u8,
+                indices.len() * core::mem::size_of::<u32>(),
+            );
+            gl.named_buffer_data_u8_slice(EBO, data, glow::STATIC_DRAW);
+
+            let stride = 5 * core::mem::size_of::<f32>() as i32;
+            gl.enable_vertex_attrib_array(0);
+            gl.vertex_attrib_pointer_f32(0, 3, glow::FLOAT, false, stride, 0);
+
+            gl.enable_vertex_attrib_array(1);
+            gl.vertex_attrib_pointer_f32(1, 2, glow::FLOAT, false, stride, (3 * core::mem::size_of::<f32>()) as i32 );
+
+            gl.bind_vertex_array(None);
+
+             plane {
+                texture: crate::model::TextureFromFile("texture.jpg", "resources", gl.clone()),
+                VAO,
+                VBO,
+                EBO
+            }
+        }
+    }
+
+    pub fn draw(&self, shader: &crate::shader::shader, camera: &Camera)
+        {
+            unsafe {
+                shader.Use();
+
+
+                let model = cgmath::Matrix4::from_angle_x(cgmath::Deg(-90.0));
+                let projection = cgmath::perspective(cgmath::Deg(camera.Zoom), SCR_WIDTH as f32 /SCR_HEIGHT as f32, 0.1, 100.0);
+                let view = camera.GetViewMatrix();
+
+                shader.setMat4("model", &model);
+                shader.setMat4("view", &view);
+                shader.setMat4("projection", &projection);
+                shader.setFloat("tile_size", 0.5);
+                shader.setFloat("scroll_speed", 10.0);
+                let camera_direction = (camera.Position - cgmath::Point3::new(0.0, 0.0, 0.0));
+                shader.setVector3("camera_position", camera_direction);
+
+                shader.gl.bind_texture(glow::TEXTURE_2D, Some(self.texture));
+                shader.gl.bind_vertex_array(Some(self.VAO));
+
+                shader.gl.draw_elements(glow::TRIANGLES, 6, glow::UNSIGNED_INT, 0);
+                shader.gl.bind_vertex_array(None);
+
+                shader.gl.active_texture(glow::TEXTURE0);
+            }
+        }
+}