feat: 传入uniform

src/main.rs

@@ -88,7 +88,9 @@ fn main() {
     unsafe { gl::BindVertexArray(vao) };
 
     // 创建VBO
-    let a: [f32; _] = [-0.5, -0.5, 0.0, 0.5, -0.5, 0.0, 0.0, 0.5, 0.0];
+    let a: [f32; _] = [
+        0.5, 0.5, 0.0, 0.5, -0.5, 0.0, -0.5, -0.5, 0.0, -0.5, 0.5, 0.0,
+    ];
     let mut vbo: u32 = 0;
     unsafe { gl::GenBuffers(1, &mut vbo) };
     unsafe { gl::BindBuffer(gl::ARRAY_BUFFER, vbo) };
@@ -114,6 +116,20 @@ fn main() {
     };
     unsafe { gl::EnableVertexAttribArray(0) };
 
+    // 创建EBO
+    let b: [u32; _] = [0, 1, 3, 1, 2, 3];
+    let mut ebo = 0;
+    unsafe { gl::GenBuffers(1, &mut ebo) };
+    unsafe { gl::BindBuffer(gl::ELEMENT_ARRAY_BUFFER, ebo) };
+    unsafe {
+        gl::BufferData(
+            gl::ELEMENT_ARRAY_BUFFER,
+            size_of_val(&b) as _,
+            b.as_ptr() as _,
+            gl::STATIC_DRAW,
+        )
+    };
+
     // 渲染循环
     while !window.should_close() {
         glfw.poll_events();
@@ -135,11 +151,23 @@ fn handle_window_event(window: &mut glfw::Window, event: glfw::WindowEvent) {
 }
 
 fn render(render_timer: &mut RenderTimer, sp: u32, vao: u32) {
+    // 设置背景颜色
     let t = render_timer.time_count() as f32 / 1000.0 as f32;
     unsafe { gl::ClearColor(t.sin() * 0.5 + 1.0, t.cos() * 0.5 + 1.0, 0.3, 1.0) };
     unsafe { gl::Clear(gl::COLOR_BUFFER_BIT) };
 
+    // 向着色器传入颜色
+    let location = unsafe { gl::GetUniformLocation(sp, "inColor".as_ptr() as _) };
+    unsafe { gl::Uniform4f(location, t.cos() * 0.5 + 1.0, t.sin() * 0.5 + 1.0, 0.7, 1.0) };
+
+    // 绘制图形
     unsafe { gl::UseProgram(sp) };
     unsafe { gl::BindVertexArray(vao) };
-    unsafe { gl::DrawArrays(gl::TRIANGLES, 0, 3) };
+    if (t as u32) % 2 == 1 {
+        unsafe { gl::PolygonMode(gl::FRONT_AND_BACK, gl::LINE) };
+    }
+    else {
+        unsafe { gl::PolygonMode(gl::FRONT_AND_BACK, gl::FILL) };
+    }
+    unsafe { gl::DrawElements(gl::TRIANGLES, 6, gl::UNSIGNED_INT, null()) };
 }

src/shaders/fs.frag

@@ -1,7 +1,9 @@
 #version 330 core
 out vec4 FragColor;
 
+uniform vec4 inColor;
+
 void main()
 {
-    FragColor = vec4(0.0, 0.8824, 1.0, 1.0);
+    FragColor = inColor;
 }