From 99b69cc14d585b3b5045037bddce50903feaac80 Mon Sep 17 00:00:00 2001
From: Able <abl3theabove@gmail.com>
Date: Sun, 4 Dec 2022 06:19:46 -0600
Subject: [PATCH] framebuffer addition

---
 .../able_graphics_library/src/commands.rs     | 42 ++++++++++++---
 .../able_graphics_library/src/framebuffer.rs  | 52 +++++++++++++++++++
 libraries/able_graphics_library/src/lib.rs    |  1 +
 libraries/able_graphics_library/src/types.rs  |  1 +
 4 files changed, 88 insertions(+), 8 deletions(-)
 create mode 100644 libraries/able_graphics_library/src/framebuffer.rs

diff --git a/libraries/able_graphics_library/src/commands.rs b/libraries/able_graphics_library/src/commands.rs
index 607e738..d90b466 100644
--- a/libraries/able_graphics_library/src/commands.rs
+++ b/libraries/able_graphics_library/src/commands.rs
@@ -1,14 +1,40 @@
-use crate::{buffer::BufferUsage, color::Color3, types::BufferID, vertex::Vertex};
+use crate::{
+    color::Color3,
+    framebuffer::FrameBuffer,
+    types::{BufferID, Position2},
+    vertex::Vertex,
+};
 
 pub enum DrawCommand {
-    UpdateFrame,
+    /// Copy one framebuffer onto another
+    UpdateFrame(UpdateFrameData),
     Clear(Color3),
     ClearBuffer(BufferID),
-
     AppendVertex(BufferID, Vertex),
-
-    MakeBuffer {
-        num_vertices: usize,
-        usage: BufferUsage,
-    },
+}
+
+/// Offset framebuffer two by offset and place it onto framebuffer one
+pub struct UpdateFrameData {
+    pub offset: Position2,
+    pub framebuffer_1: FrameBuffer,
+    pub framebuffer_2: FrameBuffer,
+}
+
+impl UpdateFrameData {
+    /// Run a few checks to make sure this is a sane action
+    pub fn sanity_check(&self) -> bool {
+        let size_check;
+        let mut x_offscreen = false;
+        let mut y_offscreen = false;
+
+        size_check = self.framebuffer_1.check_size(&self.framebuffer_2);
+        if self.offset.inner[0] > self.framebuffer_1.width as f32 {
+            x_offscreen = true
+        }
+        if self.offset.inner[1] > self.framebuffer_1.height as f32 {
+            y_offscreen = true
+        }
+
+        size_check && x_offscreen && y_offscreen
+    }
 }
diff --git a/libraries/able_graphics_library/src/framebuffer.rs b/libraries/able_graphics_library/src/framebuffer.rs
new file mode 100644
index 0000000..241ecd6
--- /dev/null
+++ b/libraries/able_graphics_library/src/framebuffer.rs
@@ -0,0 +1,52 @@
+use core::ptr;
+
+use crate::color::Color3;
+/// NOTE: Assumes the layout of RGBA
+pub struct FrameBuffer {
+    pub width: u32,
+    pub height: u32,
+    pub data: Vec<u32>,
+}
+
+impl FrameBuffer {
+    pub fn new(width: u32, height: u32) -> Self {
+        let data = vec![0; (width * height) as usize];
+        FrameBuffer {
+            width,
+            height,
+            data,
+        }
+    }
+
+    /// WARNING: Slow
+    pub fn set_pixel(&mut self, x: u32, y: u32, color: u32) {
+        let index = (y * self.width + x) as usize;
+        self.data[index] = color;
+    }
+
+    /// WARNING: Slow
+    pub fn get_pixel(&self, x: u32, y: u32) -> u32 {
+        let index = (y * self.width + x) as usize;
+        self.data[index]
+    }
+
+    /// Quickly writes the provided color to the whole framebuffer
+    pub fn clear(&mut self, color: Color3) {
+        unsafe {
+            // TODO: properly clear instead of only copying red
+            ptr::write_bytes(self.data.as_mut_ptr(), color.r, self.data.len());
+        }
+    }
+
+    // TODO(Able): Test preformance of clear2
+    #[allow(dead_code)]
+    fn clear2(&mut self, color: u32) {
+        self.data.fill(color);
+    }
+    /// Check the size of one framebuffer vs the other.
+    /// NOTE: Just because this returns false does not mean that something is wrong
+    ///     there are cases that this makes sense
+    pub fn check_size(&self, other: &FrameBuffer) -> bool {
+        self.width == other.width && self.height == other.height
+    }
+}
diff --git a/libraries/able_graphics_library/src/lib.rs b/libraries/able_graphics_library/src/lib.rs
index c999ccc..8ddbcf4 100644
--- a/libraries/able_graphics_library/src/lib.rs
+++ b/libraries/able_graphics_library/src/lib.rs
@@ -1,6 +1,7 @@
 pub mod buffer;
 pub mod color;
 pub mod commands;
+pub mod framebuffer;
 pub mod types;
 pub mod vertex;
 
diff --git a/libraries/able_graphics_library/src/types.rs b/libraries/able_graphics_library/src/types.rs
index 926fbf8..530c1b2 100644
--- a/libraries/able_graphics_library/src/types.rs
+++ b/libraries/able_graphics_library/src/types.rs
@@ -9,3 +9,4 @@ pub struct Float2Array {
 }
 
 pub type Position3 = Float3Array;
+pub type Position2 = Float2Array;