WIP: Implementing the r_<FOO> files

src/d_main/mod.rs

@@ -11,6 +11,7 @@ use crate::m_argv::PARM_NOT_FOUND;
 use crate::m_menu::M_Init;
 use crate::m_misc::M_LoadDefaults;
 
+use crate::renderer::R_Init;
 use crate::v_video::V_Init;
 use crate::w_wad::{W_CheckNumForName, W_InitMultipleFiles};
 use crate::z_zone::Z_Init;
@@ -466,15 +467,15 @@ pub fn D_DoomMain() {
 	    ===========================================================================\n")
         }
     }
-
     
     println!("M_Init: Init miscellaneous info.");
     M_Init();
 
+    println!("R_Init: Init DOOM refresh daemon - ");
+    R_Init();
+
     // TODO: Implement other inits
     /*
-    println!("R_Init: Init DOOM refresh daemon - ")
-    R_Init();
 
     println!("P_Init: Init Playloop state.");
     P_Init();

src/doomtype/mod.rs

@@ -1,10 +1,10 @@
-const MAXCHAR: i8 = i8::MAX;
+pub const MAXCHAR: i8 = i8::MAX;
-const MAXSHORT: i16 = i16::MAX;
+pub const MAXSHORT: i16 = i16::MAX;
-const MAXINT: i32 = i32::MAX;
+pub const MAXINT: i32 = i32::MAX;
-const MAXLONG: i32 = i32::MAX;
+pub const MAXLONG: i32 = i32::MAX;
 
 // Minimum values
-const MINCHAR: i8 = i8::MIN;
+pub const MINCHAR: i8 = i8::MIN;
-const MINSHORT: i16 = i16::MIN;
+pub const MINSHORT: i16 = i16::MIN;
-const MININT: i32 = i32::MIN;
+pub const MININT: i32 = i32::MIN;
-const MINLONG: i32 = i32::MIN;
+pub const MINLONG: i32 = i32::MIN;

src/m_menu/mod.rs

@@ -245,10 +245,13 @@ static mut whichSkull: i32 = 0;
 static mut skullAnimCounter: i32 = 0;
 
 #[allow(non_upper_case_globals)]
-static mut screenSize: i32 = 0;
+pub(crate) static mut detailLevel: i32 = 0;
 
 #[allow(non_upper_case_globals)]
-static mut screenBlocks: i32 = 0;
+pub static mut screenSize: i32 = 0;
+
+#[allow(non_upper_case_globals)]
+pub(crate) static mut screenBlocks: i32 = 0;
 
 #[allow(non_upper_case_globals)]
 static mut messageToPrint: i32 = 0;

src/main.rs

@@ -6,6 +6,7 @@ mod hu_stuff;
 mod m_argv;
 mod m_menu;
 mod m_misc;
+mod renderer;
 mod v_video;
 mod w_wad;
 mod z_zone;

src/math/m_fixed.rs

@@ -2,46 +2,63 @@
 
 This provides fixed-point arithmetic as 32-bit 16.16
 */
+use std::ops::ShrAssign;
+
+use crate::doomtype::{
+    MININT,
+    MAXINT
+};
 
 pub const FRACBITS: i32 = 16;
 pub const FRACUNIT: i32 = 1 << FRACBITS;
 
-pub const MININT: i32 = 0x80000000;
+
-pub const MAXINT: i32 = 0x7fffffff;
 /// Struct representing a fixed point 32-bit value
 #[derive(Copy, Clone, PartialEq, Debug)]
-pub struct FixedPoint {
+#[allow(non_camel_case_types)]
+pub struct fixed_t {
     pub value: i32,
 }
 
-impl FixedPoint {
+impl fixed_t {
 
+    pub const fn new(val: i32) -> Self {
+        fixed_t { value: val }
+    }
+    
     #[allow(non_snake_case)]
-    pub fn FixedMul(a: FixedPoint, b: FixedPoint) -> FixedPoint {
+    pub fn FixedMul(a: fixed_t, b: fixed_t) -> fixed_t {
         let value = ((a.value as u64) * (b.value as u64) >> FRACBITS) as i32;
-        FixedPoint{value}
+        fixed_t{value}
     }
 
     #[allow(non_snake_case)]
-    pub fn FixedDiv(a: FixedPoint, b: FixedPoint) -> FixedPoint {
+    pub fn FixedDiv(a: fixed_t, b: fixed_t) -> fixed_t {
         if (i32::abs(a.value) >> 14) >= i32::abs(b.value) {
             if a.value^b.value == 0 {
-                FixedPoint{value: MININT};
+                fixed_t{value: MININT};
             }
             else {
-               FixedPoint{value: MAXINT};
+               fixed_t{value: MAXINT};
             }
         }
-        FixedPoint::FixedDiv2(a,b)
+        fixed_t::FixedDiv2(a,b)
     }
 
     #[allow(non_snake_case)]
-    pub fn FixedDiv2(a: FixedPoint, b: FixedPoint) -> FixedPoint {
+    pub fn FixedDiv2(a: fixed_t, b: fixed_t) -> fixed_t {
         let c: f64 = ((a.value as f64) / (b.value as f64)) * FRACUNIT as f64;
         if c >= 2147483648.0 || c < -2147483648.0 {
             panic!("FixedDiv: divide by zero");
         }
-        FixedPoint { value: c as i32 }
+        fixed_t { value: c as i32 }
     }
 
-} 
+} 
+
+impl ShrAssign<i32> for fixed_t {
+    fn shr_assign(&mut self, rhs: i32) {
+        // Shift the underlying wrapped i32 value directly
+        self.value >>= rhs;
+    }
+}

src/math/mod.rs

@@ -1,3 +1,5 @@
-// pub mod m_fixed;
+mod m_fixed;
 
-// pub use m_fixed::FixedPoint;
+pub use m_fixed::fixed_t;
+pub use m_fixed::FRACUNIT;
+pub use m_fixed::FRACBITS;

src/renderer/mod.rs

@@ -0,0 +1,130 @@
+// Main entry to Render stuff
+// i.e r_main c/h
+mod r_data;
+mod r_defs;
+mod r_plane;
+
+
+use crate::doomdef::SCREENWIDTH;
+use crate::math::{fixed_t, FRACUNIT};
+use crate::m_menu::{detailLevel, screenBlocks};
+use r_data::R_InitData;
+use r_defs::lighttable_t;
+use r_plane::R_InitPlanes;
+
+// Light constants
+// Orignal source comment: Now why not 32 levels here?
+pub const LIGHTLEVELS: i32 = 16;
+pub const MAXLIGHTSCALE: i32 = 48;
+pub const LIGHTSCALESHIFT: i32 = 12;
+pub const MAXLIGHTZ: i32 = 128;
+pub const LIGHTZSHIFT: i32 = 20;
+
+#[allow(non_upper_case_globals)]
+pub static mut scalelight: [[*mut lighttable_t; MAXLIGHTSCALE as usize]; LIGHTLEVELS as usize] = 
+    [[std::ptr::null_mut(); MAXLIGHTSCALE as usize]; LIGHTLEVELS as usize];
+
+#[allow(non_upper_case_globals)]
+pub static mut scalelightfixed: [*mut lighttable_t; MAXLIGHTSCALE as usize] = 
+    [std::ptr::null_mut(); MAXLIGHTSCALE as usize];
+
+#[allow(non_upper_case_globals)]
+pub static mut zlight: [[*mut lighttable_t; MAXLIGHTZ as usize]; LIGHTLEVELS as usize] = 
+    [[std::ptr::null_mut(); MAXLIGHTZ as usize]; LIGHTLEVELS as usize];
+
+/// R_InitLightTables
+/// Only inits the zlight table,
+///  because the scalelight table changes with view size.
+pub const DISTMAP:i32 = 2;
+
+
+/// Number of diminishing brightness levels.
+/// There a 0-31, i.e. 32 LUT in the COLORMAP lump.
+pub const NUMCOLORMAPS: i32 =  32;
+
+#[allow(non_upper_case_globals)]
+static mut viewcos: fixed_t = fixed_t{value: 0};
+
+#[allow(non_upper_case_globals)]
+static mut viewsin: fixed_t = fixed_t{value: 0};
+
+#[allow(non_upper_case_globals)]
+static mut setsizeneeded: bool = false;
+
+#[allow(non_upper_case_globals)]
+static mut setblocks: i32 = 0;
+
+#[allow(non_upper_case_globals)]
+static mut setdetail: i32 = 0;
+
+
+
+#[allow(non_snake_case)]
+fn R_InitPointToAngle() {
+    // this is unused in the original source
+    // we get this data from tables
+}
+
+#[allow(non_snake_case)]
+fn R_InitTables() {
+    // this is unused in the original source
+    // we get this data from tables
+}
+
+#[allow(non_snake_case)]
+fn R_InitLightTables() {
+    let mut startmap: i32;
+    let mut scale: fixed_t;
+    let mut level: i32;
+    for i in 0..(LIGHTLEVELS as usize) {
+        startmap = ((LIGHTLEVELS - 1 - (i as i32)) * 2) * NUMCOLORMAPS/LIGHTLEVELS;
+        for j in 0..(MAXLIGHTZ as usize) {
+            scale = fixed_t::FixedDiv(fixed_t{value: (SCREENWIDTH/2*FRACUNIT)}, fixed_t{value: ((j as i32) + 1) << LIGHTZSHIFT});
+            scale >>= LIGHTSCALESHIFT;
+
+            level = startmap - scale.value/DISTMAP;
+            level = level.clamp(0, NUMCOLORMAPS - 1);
+
+            // zlight[i][j] = colormaps + level * 256; //TODO: Implement zlight
+        }
+    }
+}
+
+
+
+/* // TODO: Implement player_t
+pub fn R_RenderPlayerView(player: *const player_t) {
+
+} 
+*/
+
+#[allow(non_snake_case)]
+pub fn R_Init() {
+    R_InitData();
+    println!("R_InitData");
+    R_InitPointToAngle();
+    println!("R_InitPointToAngle");
+    R_InitTables();
+    // viewwidth / viewheight / detailLevel are set by the defaults
+    println!("R_InitTables");
+    unsafe {R_SetViewSize(screenBlocks, detailLevel);}
+    R_InitPlanes();
+    println!("R_InitPlanes");
+    R_InitLightTables();
+    println!("R_InitLightTables");
+    //R_InitSkyMap();
+    println!("R_InitSkyMap");
+    //R_InitTranslationTables();
+    println!("R_InitTranslationTables")
+
+    // framecount = 0;
+}
+
+#[allow(non_snake_case)]
+pub fn R_SetViewSize(blocks: i32, detail: i32) {
+    unsafe {
+        setsizeneeded = true;
+        setblocks = blocks;
+        setdetail = detail;
+    }
+}

src/renderer/r_data.rs

@@ -0,0 +1,60 @@
+#[allow(non_snake_case)]
+fn R_InitTextures() {
+
+}
+
+#[allow(non_snake_case)]
+fn R_InitFlats() {
+
+}
+
+#[allow(non_snake_case)]
+fn R_InitSpriteLumps() {
+
+}
+
+#[allow(non_snake_case)]
+fn R_InitColormaps() {
+
+}
+
+#[allow(non_snake_case)]
+pub fn R_GetColumn (tex: i32, col: i32) {
+
+}
+
+
+/// R_InitData
+/// Locates all the lumps that will be used by all views
+/// This must be called after `W_Init`
+#[allow(non_snake_case)]
+pub fn R_InitData() {
+    R_InitTextures();
+    println!("InitTextures");
+    R_InitFlats();
+    println!("InitFlats");
+    R_InitSpriteLumps();
+    println!("InitSprites");
+    R_InitColormaps();
+    println!("InitColormaps");
+}
+
+#[allow(non_snake_case)]
+pub fn R_PrecacheLevel() {
+
+}
+
+#[allow(non_snake_case)]
+pub fn R_FlatNumForName(name: &str) -> i32 {
+    1
+}
+
+#[allow(non_snake_case)]
+pub fn R_TextureNumForName(name: &str) -> i32 {
+    1
+}
+
+#[allow(non_snake_case)]
+pub fn R_CheckTextureNumForName(name: &str) -> i32 {
+    1
+}

src/renderer/r_defs.rs

@@ -0,0 +1,441 @@
+use crate::doomdef::SCREENWIDTH;
+use crate::m_fixed::{fixed_t};
+use crate::tables::angle_t;
+
+// TODO: Implement d_think.h and p_mobj.h
+
+/// Original Source comment: 
+/// Silhouette, needed for clipping Segs (mainly)
+/// and sprites representing things.
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+#[repr(i32)]
+pub enum Silhouette {
+    None = 0,
+    Bottom = 1,
+    Top = 2,
+    Both = 3,
+}
+
+pub const MAXDRAWSEGS: i32 = 256;
+
+/// Original source comment
+/// This could be wider for >8 bit display.
+/// Indeed, true color support is posibble
+///  precalculating 24bpp lightmap/colormap LUT.
+///  from darkening PLAYPAL to all black.
+/// Could even us emore than 32 levels.
+type lighttable_t = u8;
+
+/// Original Source comment: 
+/// Your plain vanilla vertex.
+/// Note: transformed values not buffered locally,
+///  like some DOOM-alikes ("wt", "WebView") did.
+#[derive(Copy, Clone)]
+pub struct vertex_t {
+    x: fixed_t,
+    y: fixed_t
+}
+
+/// Original Source comment: 
+/// Each sector has a degenmobj_t in its center
+///  for sound origin purposes.
+/// I suppose this does not handle sound from
+///  moving objects (doppler), because
+///  position is prolly just buffered, not
+///  updated.
+pub struct degenmobj_t {
+    //TODO: implement d_think.h
+    // thinker: thinker_t,
+    x: fixed_t,
+    y: fixed_t,
+    z: fixed_t    
+}
+
+/// Sectors represent a distinct, closed polygon area on the map with uniform 
+/// floor heights, ceiling heights, lighting levels, and floor/ceiling textures.
+/// They also serve as containers for gameplay entities (`mobj_t`).
+/// Original Source comment: 
+/// The SECTORS record, at runtime.
+/// Stores things/mobjs.
+pub struct sector_t {
+    /// Height of the floor
+    pub(crate) floorheight: fixed_t,
+
+    /// Height of the ceiling
+    pub(crate) ceilingheight: fixed_t,
+
+    /// Texture index applied to the floor surface
+    pub(crate) floorpic: i16,
+
+    /// Texture index applied to the ceiling surface
+    pub(crate) ceilingpic: i16,
+
+    /// The current brightness level for the sector
+    pub(crate) lightlevel: i16,
+
+    /// Sector type/behaviour flags (e.g sewage / lava damaging floors)
+    pub(crate) special: i16,
+
+    /// Unique ID tag used by linedef triggers to identify and manipluate this sector
+    pub(crate) tag: i16,
+    
+    /// Sound propagation state variable used during sound traversal calculations.
+    /// Values: 0 = untraversed, 1 or 2 = sound lines - 1.
+    pub(crate) soundtraversed: i32,
+
+    //TODO: mobj_t implementation (p_mobj.h)
+    /// Pointer to the map object (`mobj_t`) that generated a sound in this sector, or null.
+    pub(crate) soundtarget: *mut mobj_t,
+
+    /// A bounding box `[ymin, ymax, xmin, xmax]` mapping blocks for height changes and collisions.
+    pub(crate) blockbox: [i32; 4],
+
+    ///  simplified, stationary map object representing the central origin point for sound playback.
+    pub(crate) soundorg: degenmobj_t,
+
+    /// A frame check counter variable used to avoid re-processing this sector multiple times per tick.
+    pub(crate) validcount: i32,
+
+    /// A dynamic collection of all map objects currently inside this sector.
+    /// TODO: Change back to *mut mobj_t linked list later
+    pub(crate) thinglist: Vec<mobj_t>,
+
+    /// A generic raw pointer to an active thinker struct (e.g., `plat_t`, `ceiling_t`) for handling moving parts
+    pub(crate) specialdata: *mut (), 
+
+    /// The total number of linedefs that form the boundaries of this sector.
+    pub(crate) linecount: i32,
+
+    /// A raw pointer to an array of pointers pointing to the `line_s` (linedef) structs that border this sector.
+    pub(crate) lines: *mut *mut line_s, 
+}
+
+/// Linedefs are made up of either one or two sidedefs (front and back). 
+/// A sidedef contains texture alignment offsets, texture indices, and 
+/// points directly to the sector it faces.
+pub struct sidedef_t {
+
+    /// Horizontal alignment offset added to the calculated texture column.
+    pub(crate) textureoffset: fixed_t,
+
+     /// Vertical alignment offset added to the calculated texture top.
+    pub(crate) rowoffset: fixed_t, 
+
+    // texture indices
+
+    /// The index of the upper wall texture (above the ceiling gap).
+    pub(crate) toptexture: i16,
+
+    /// The index of the lower wall texture (below the floor gap).
+    pub(crate) bottomtexture: i16,
+
+    /// The index of the middle wall texture (used on single-sided walls or windows).
+    pub(crate) midtexture: i16,
+    
+    /// A raw pointer to the sector this specific side faces.
+    pub(crate) sector: *mut sector_t,
+}
+
+/// The line slope classification type.
+/// 
+/// Used by the collision and rendering engines to optimize intersection 
+/// checks and line-of-sight tracking based on the orientation of a wall line.
+#[derive(Copy, Clone)]
+enum slopetype_t {
+
+    /// A perfectly horizontal line (dy == 0).
+    ST_HORIZONTAL,
+
+    /// A perfectly vertical line (dx == 0).
+    ST_VERTICAL,
+
+    /// A line with a positive slope rising from bottom-left to top-right (dx and dy have the same sign).
+    ST_POSITIVE,
+
+    /// A line with a negative slope falling from top-left to bottom-right (dx and dy have opposite signs).
+    ST_NEGATIVE
+}
+
+
+/// Linedefs form the walls and structural geometry of a map. They contain
+/// pointers to their start/end vertices, front/back siding data, physical 
+/// triggers (`special`), and precalculated bounding extents to assist the physics engine.
+pub struct linedef_t {
+     /// Raw pointer to the starting vertex (v1) of the wall.
+    pub(crate) v1: *mut vertex_t,
+    
+    /// Raw pointer to the ending vertex (v2) of the wall.
+    pub(crate) v2: *mut vertex_t,
+
+    /// Precalculated horizontal delta value (v2.x - v1.x) for quick side-of-line checking.
+    pub(crate) dx: fixed_t,
+    
+    /// Precalculated vertical delta value (v2.y - v1.y) for quick side-of-line checking.
+    pub(crate) dy: fixed_t,
+
+    /// Configuration flags handling behavior (e.g., solid wall, blocks monsters, secret map wall).
+    pub(crate) flags: i16,
+    
+    /// The linedef activation type/trigger function index (e.g., doors, teleporters, lifts).
+    pub(crate) special: i16,
+    
+    /// A unique ID tag matching sector targets to process execution triggers.
+    pub(crate) tag: i16,
+
+    /// Sidedef lookups. `sidenum[0]` is the front side; `sidenum[1]` is the back side (or -1 if single-sided).
+    pub(crate) sidenum: [i16; 2],			
+
+    /// Bounding box layout `[ymin, ymax, xmin, xmax]` representing the full grid extent of the line.
+    pub(crate) bbox: [fixed_t; 4],
+
+    /// Slope classification used to optimize physics intersection and visibility clipping loops.
+    pub(crate) slopetype: slopetype_t,
+
+    /// Raw pointer to the sector directly in front of this linedef's first side.
+    pub(crate) frontsector: *mut sector_t,
+    
+    /// Raw pointer to the sector behind this linedef's second side, or null if single-sided.
+    pub(crate) backsector: *mut sector_t,
+
+    /// A frame counter lookup variable used to avoid parsing or processing this line multiple times per tick.
+    pub(crate) validcount: i32,
+
+    /// A generic raw pointer to a running thinker action layout (e.g., standard scrolling wall textures).
+    pub(crate) specialdata: *mut (),		
+}
+
+
+/// Subsectors are the structural leaves at the bottom of the BSP tree. 
+/// They represent smaller, guaranteed-convex sub-polygons carved out of a 
+/// larger sector, defined by a sequential slice of rendering lines (`seg_t`).
+pub struct subsectordef_t {
+    /// A raw pointer to the parent sector that this subsector belongs to.
+    pub(crate) sector: *mut sector_t,
+
+    /// The total number of consecutive line segments (`seg_t`) that form this subsector.
+    pub(crate) numlines: i16,
+
+    /// The starting array index inside the global `segs` array for this subsector's lines.
+    pub(crate) firstline: i16,
+}
+
+/// Segs are clipped slices of linedefs generated by the node builder. 
+/// The rendering engine processes them in strict front-to-back order 
+/// using the BSP tree to draw wall surfaces without sorting artifacts.
+pub struct segdef_t {
+    /// Raw pointer to the starting vertex (v1) of this specific segment.
+    pub(crate) v1: *mut vertex_t,
+
+    /// Raw pointer to the ending vertex (v2) of this specific segment.
+    pub(crate) v2: *mut vertex_t,
+    
+    /// The distance offset along the original linedef where this segment begins.
+    pub(crate) offset: fixed_t,
+
+    /// The absolute binary angle of the segment (represented as a 32-bit unsigned integer).
+    pub(crate) angle: angle_t,
+
+    /// Raw pointer to the sidedef structure containing the texture data for this segment.
+    pub(crate) sidedef: *mut sidedef_t,
+
+    /// Raw pointer to the parent linedef structure this segment was split out from.
+    pub(crate) linedef: *mut linedef_t,
+
+    /// Raw pointer to the sector directly in front of this segment.
+    pub(crate) frontsector: *mut sector_t,
+
+    /// Raw pointer to the sector behind this segment, or null if it belongs to a solid one-sided wall.
+    pub(crate) backsector: *mut sector_t,
+}
+
+/// Nodes form the internal branching skeleton of the map's 3D visibility tree.
+/// Each node acts as a cutting plane line segment that splits a sub-region into
+pub struct node_t {
+    /// Starting X coordinate of the division splitter line.
+    pub(crate) x: fixed_t,
+
+    /// Starting Y coordinate of the division splitter line.
+    pub(crate) y: fixed_t,
+    
+    /// Horizontal delta length of the division splitter vector.
+    pub(crate) dx: fixed_t,
+    
+    /// Vertical delta length of the division splitter vector.
+    pub(crate) dy: fixed_t,
+
+    /// Precalculated bounding boxes [ymin, ymax, xmin, xmax] for the right [0] and left [1] child spaces.
+    pub(crate) bbox: [[FixedT; 4]; 2],
+
+    /// References to left [0] and right [1] children. If highest bit (0x8000) is set, it targets a subsector_t index.
+    pub(crate) children: [u16; 2],
+}
+
+/// A runtime record of a drawn wall segment.
+/// Stores clipping and scaling metadata to correctly occlude and scale sprites behind it.
+pub struct drawseg_t {
+    /// Pointer to the line segment being rendered (usually seg_t).
+    pub(crate) curline: *mut sector_t,
+
+    /// Starting horizontal screen column (left boundary).
+    pub(crate) x1: i32,
+    
+    /// Ending horizontal screen column (right boundary).
+    pub(crate) x2: i32,
+
+    /// Initial texture scale at the starting column (x1).
+    pub(crate) scale1: fixed_t,
+
+    /// Final texture scale at the ending column (x2).
+    pub(crate) scale2: fixed_t,
+
+    /// Amount to change the texture scale per horizontal pixel step.
+    pub(crate) scalestep: fixed_t,
+
+    /// Silhouette type flags handling sprite occlusion (e.g., SIL_BOTTOM, SIL_TOP).
+    pub(crate) silhouette: i32,
+
+    /// Maximum floor height boundary for bottom silhouette clipping.
+    pub(crate) bsilheight: fixed_t,
+
+    /// Minimum ceiling height boundary for top silhouette clipping.
+    pub(crate) tsilheight: fixed_t,
+
+    /// Pointer to the screen column array managing top clipping bounds for sprites.
+    pub(crate) sprtopclip: *mut u16,
+
+    /// Pointer to the screen column array managing bottom clipping bounds for sprites.
+    pub(crate) sprbottomclip: *mut u16,
+
+    /// Pointer to the column offset array used for rendering masked textures.
+    pub(crate) maskedtexturecol: *mut u16,
+}
+
+/// A hardware-agnostic 2D picture or graphic asset.
+/// Uses a column-oriented format to optimize rapid vertical stretching and scaling.
+pub struct patch_t {
+    /// Total width of the graphic patch in pixels.
+    pub(crate) width: u16,
+    
+    /// Total height of the graphic patch in pixels.
+    pub(crate) height: u16,
+
+    /// Horizontal offset relative to the origin (used to center weapon and sprite frames).
+    pub(crate) leftoffset: u16,
+
+    /// Vertical offset relative to the origin (used to center weapon and sprite frames).
+    pub(crate) topoffset: u16,
+
+    /// Array of byte offsets from the start of the patch to the start of each vertical pixel column.
+    /// only [width] used
+    // the [0] is &columnofs[width] 
+    pub(crate) columnofs: [i32; 8],
+}
+
+/// A visible sprite entry prepared for rendering.
+/// Tracks screen bounds, scaling, and clipping parameters for a partly visible map object.
+pub struct vissprite_t {
+    /// Pointer to the previous sprite in the doubly linked list.
+    pub(crate) prev: *mut vissprite_t,
+    
+    /// Pointer to the next sprite in the doubly linked list.
+    pub(crate) next: *mut vissprite_t,
+    
+    /// Starting horizontal screen column (left boundary).
+    pub(crate) x1: i32,
+    
+    /// Ending horizontal screen column (right boundary).
+    pub(crate) x2: i32,
+
+    /// Global X coordinate used for line-side visibility checks.
+    pub(crate) gx: fixed_t,
+    
+    /// Global Y coordinate used for line-side visibility checks.
+    pub(crate) gy: fixed_t,		
+
+    /// Global bottom Z coordinate used for silhouette clipping calculations.
+    pub(crate) gz: fixed_t,
+    
+    /// Global top Z coordinate used for silhouette clipping calculations.
+    pub(crate) gzt: fixed_t,
+
+    /// Horizontal texture offset fraction at screen column x1.
+    pub(crate) startfrac: fixed_t,
+    
+    /// Scale factor of the sprite relative to its distance from the camera.
+    pub(crate) scale: fixed_t,
+    
+    /// Horizontal step scale factor (inverted and negative if the sprite is flipped).
+    pub(crate) xiscale: fixed_t,	
+
+    /// Vertical texture alignment midpoint coordinate.
+    pub(crate) texturemid: fixed_t,
+    
+    /// The index of the graphic patch asset being rendered.
+    pub(crate) patch: i32,
+
+    /// Pointer to the color lookup array handling lighting, shadows, and full-brightness frames.
+    pub(crate) colormap: *mut lighttable_t,
+   
+    /// Cached copy of the parent map object's physics and state flags.
+    pub(crate) mobjflags: i32,
+}
+
+/// Animation frame data for a sprite object.
+/// Tracks raw graphic lump IDs and horizontal flip bits for all 8 view rotations.
+#[derive(Copy, Clone)]
+pub struct spriteframe_t {
+    /// True if the sprite has directional rotation variants; false if it looks identical from all sides.
+    pub(crate) rotate: bool,
+
+    /// WAD graphic lump indices representing the image assets for view angles 0 to 7.
+    pub(crate) lump: [i16; 8],
+
+    /// Bitmask flags (1 = mirror image horizontally) applied to view angles 0 to 7 to save space.
+    pub(crate) flip: [u8; 8],
+}
+
+/// A top-level sprite asset container managing a series of sequential animation frames.
+pub struct spritedef_t {
+    /// Total number of animation frames allocated for this sprite sequence.
+    pub(crate) numframes: i32,
+
+    /// Raw pointer to the array of frame records tracking rotation and asset data.
+    pub(crate) spriteframes: *mut spriteframe_t,
+}
+
+/// A floor or ceiling polygon segment prepared for flat horizontal texture mapping.
+/// Merges drawing spans to prevent visible gaps or layout cracking during screen refresh.
+pub struct visplane_t {
+    /// Absolute height level of the floor or ceiling plane in fixed-point space.
+    pub(crate) height: fixed_t,
+
+    /// WAD graphic texture flat index applied to the surface.
+    pub(crate) picnum: i32,
+
+    /// Calculated light/brightness visibility level of the flat polygon plane.
+    pub(crate) lightlevel: i32,
+
+    /// The leftmost horizontal screen column index bound for drawing.
+    pub(crate) minx: i32,
+
+    /// The rightmost horizontal screen column index bound for drawing.
+    pub(crate) maxx: i32,
+  
+    /// Memory padding byte mimicking historical x-1 lookups.
+    pub(crate) pad1: u8,
+
+    /// Dynamic horizontal boundary array tracing top rendering margins across columns.
+    pub(crate) top: [u8; SCREENWIDTH],
+
+    /// Memory padding byte mimicking historical array bounds checks.
+    pub(crate) pad2: u8,
+
+    /// Memory padding byte mimicking historical array bounds checks.
+    pub(crate) pad3: u8,
+
+    /// Dynamic horizontal boundary array tracing bottom rendering margins across columns.
+    pub(crate) bottom: [u8; SCREENWIDTH],
+
+    /// Memory padding byte mimicking historical x+1 lookups.
+    pub(crate) pad4: u8,
+}

src/renderer/r_plane.rs

@@ -0,0 +1,39 @@
+#[allow(non_snake_case)]
+pub fn R_InitPlanes() {
+    // Original source comment
+    // doh!
+    // wtf?
+}
+
+#[allow(non_snake_case)]
+pub fn R_ClearPlanes() {
+
+}
+
+#[allow(non_snake_case)]
+pub fn R_MapPlane (y: i32, x1: i32, x2: i32) {
+
+}
+
+#[allow(non_snake_case)]
+pub fn R_MakeSpans(x: i32, t1: i32, b1: i32, t2: i32, b2: i32) {
+
+}
+
+#[allow(non_snake_case)]
+pub fn R_DrawPlanes() {
+
+}
+
+/*  TODO: Implement visplane_t
+
+#[allow(non_snake_case)]
+pub fn R_FindPlane(height: fixed_t, picnum: i32, lightlevel: i32) -> *const visplane_t {
+
+}
+
+#[allow(non_snake_case)]
+pub fn R_CheckPlane(pl: *const visplane_t, start: i32, stop: i32) -> *const visplane_t {
+
+}
+*/