From a0dce2164cf348416ea15c63c5baa52afa66508f Mon Sep 17 00:00:00 2001
From: HampusM <hampus@hampusmat.com>
Date: Sat, 22 Jun 2024 14:00:27 +0200
Subject: feat(engine): add ability to change polygon mode per object

---
 engine/src/draw_flags.rs      | 49 +++++++++++++++++++++++++++++++++++++++++++
 engine/src/lib.rs             |  1 +
 engine/src/opengl/mod.rs      | 49 +++++++++++++++++++++++++++++++++++++++++++
 engine/src/renderer/opengl.rs | 22 ++++++++++++++++++-
 4 files changed, 120 insertions(+), 1 deletion(-)
 create mode 100644 engine/src/draw_flags.rs

diff --git a/engine/src/draw_flags.rs b/engine/src/draw_flags.rs
new file mode 100644
index 0000000..c8c11c9
--- /dev/null
+++ b/engine/src/draw_flags.rs
@@ -0,0 +1,49 @@
+use ecs::Component;
+
+use crate::util::builder;
+
+builder! {
+/// Flags for how a object should be drawn.
+#[builder(name = Builder, derives = (Debug, Default, Clone))]
+#[derive(Debug, Default, Clone, Component)]
+#[non_exhaustive]
+pub struct DrawFlags
+{
+    pub polygon_mode_config: PolygonModeConfig,
+}
+}
+
+impl DrawFlags
+{
+    pub fn builder() -> Builder
+    {
+        Builder::default()
+    }
+}
+
+#[derive(Debug, Default, Clone)]
+pub struct PolygonModeConfig
+{
+    pub face: PolygonModeFace,
+    pub mode: PolygonMode,
+}
+
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum PolygonMode
+{
+    Point,
+    Line,
+
+    #[default]
+    Fill,
+}
+
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum PolygonModeFace
+{
+    Front,
+    Back,
+
+    #[default]
+    FrontAndBack,
+}
diff --git a/engine/src/lib.rs b/engine/src/lib.rs
index f9daac3..bd954be 100644
--- a/engine/src/lib.rs
+++ b/engine/src/lib.rs
@@ -24,6 +24,7 @@ mod util;
 pub mod camera;
 pub mod data_types;
 pub mod delta_time;
+pub mod draw_flags;
 pub mod event;
 pub mod file_format;
 pub mod input;
diff --git a/engine/src/opengl/mod.rs b/engine/src/opengl/mod.rs
index 40f0c58..0b1bb8a 100644
--- a/engine/src/opengl/mod.rs
+++ b/engine/src/opengl/mod.rs
@@ -33,6 +33,13 @@ pub fn clear_buffers(mask: BufferClearMask)
     }
 }
 
+pub fn set_polygon_mode(face: impl Into<PolygonModeFace>, mode: impl Into<PolygonMode>)
+{
+    unsafe {
+        gl::PolygonMode(face.into() as u32, mode.into() as u32);
+    }
+}
+
 pub fn enable(capacity: Capability)
 {
     unsafe {
@@ -56,3 +63,45 @@ pub enum Capability
     DepthTest = gl::DEPTH_TEST,
     MultiSample = gl::MULTISAMPLE,
 }
+
+#[derive(Debug)]
+#[repr(u32)]
+pub enum PolygonMode
+{
+    Point = gl::POINT,
+    Line = gl::LINE,
+    Fill = gl::FILL,
+}
+
+impl From<crate::draw_flags::PolygonMode> for PolygonMode
+{
+    fn from(mode: crate::draw_flags::PolygonMode) -> Self
+    {
+        match mode {
+            crate::draw_flags::PolygonMode::Point => Self::Point,
+            crate::draw_flags::PolygonMode::Fill => Self::Fill,
+            crate::draw_flags::PolygonMode::Line => Self::Line,
+        }
+    }
+}
+
+#[derive(Debug)]
+#[repr(u32)]
+pub enum PolygonModeFace
+{
+    Front = gl::FRONT,
+    Back = gl::BACK,
+    FrontAndBack = gl::FRONT_AND_BACK,
+}
+
+impl From<crate::draw_flags::PolygonModeFace> for PolygonModeFace
+{
+    fn from(face: crate::draw_flags::PolygonModeFace) -> Self
+    {
+        match face {
+            crate::draw_flags::PolygonModeFace::Front => Self::Front,
+            crate::draw_flags::PolygonModeFace::Back => Self::Back,
+            crate::draw_flags::PolygonModeFace::FrontAndBack => Self::FrontAndBack,
+        }
+    }
+}
diff --git a/engine/src/renderer/opengl.rs b/engine/src/renderer/opengl.rs
index 35f4938..108c504 100644
--- a/engine/src/renderer/opengl.rs
+++ b/engine/src/renderer/opengl.rs
@@ -14,6 +14,7 @@ use ecs::{Component, Query};
 use crate::camera::Camera;
 use crate::color::Color;
 use crate::data_types::dimens::Dimens;
+use crate::draw_flags::{DrawFlags, PolygonModeConfig};
 use crate::event::{Present as PresentEvent, Start as StartEvent};
 use crate::lighting::{DirectionalLight, GlobalLight, PointLight};
 use crate::material::{Flags as MaterialFlags, Material};
@@ -102,6 +103,7 @@ fn render(
         Option<MaterialFlags>,
         Option<Position>,
         Option<Scale>,
+        Option<DrawFlags>,
     )>,
     point_light_query: Query<(PointLight,)>,
     directional_lights: Query<(DirectionalLight,)>,
@@ -137,7 +139,9 @@ fn render(
 
     clear_buffers(BufferClearMask::COLOR | BufferClearMask::DEPTH);
 
-    for (mesh, shader_program, material, material_flags, position, scale) in &query {
+    for (mesh, shader_program, material, material_flags, position, scale, draw_flags) in
+        &query
+    {
         let material_flags = material_flags
             .map(|material_flags| material_flags.clone())
             .unwrap_or_default();
@@ -187,7 +191,23 @@ fn render(
 
         shader_program.activate();
 
+        if let Some(draw_flags) = &draw_flags {
+            crate::opengl::set_polygon_mode(
+                draw_flags.polygon_mode_config.face,
+                draw_flags.polygon_mode_config.mode,
+            )
+        }
+
         draw_mesh(&mesh);
+
+        if draw_flags.is_some() {
+            let default_polygon_mode_config = PolygonModeConfig::default();
+
+            crate::opengl::set_polygon_mode(
+                default_polygon_mode_config.face,
+                default_polygon_mode_config.mode,
+            )
+        }
     }
 }
 
-- 
cgit v1.2.3-18-g5258