Support for rgba encoded heightmaps

Cargo.toml

@@ -8,3 +8,4 @@ edition = "2018"
 brs = "0.2.0"
 image = "0.23.4"
 clap = "2.33.0"
+byteorder = "1.3.4"

README.md

@@ -21,6 +21,7 @@ Compile or download from releases.
     FLAGS:
             --cull       Automatically remove bottom level bricks
         -h, --help       Prints help information
+            --hdmap      Using a high detail rgb color encoded heightmap
             --old        Use old unoptimized heightmap code
             --snap       Snap bricks to the brick grid
             --tile       Render bricks as tiles

src/main.rs

@@ -27,6 +27,7 @@ fn main() {
         (@arg snap: --snap "Snap bricks to the brick grid")
         (@arg img: -i --img "Make the heightmap flat and render an image")
         (@arg old: --old "Use old unoptimized heightmap code")
+        (@arg hdmap: --hdmap "Using a high detail rgb color encoded heightmap")
     )
     .get_matches();
 
@@ -61,6 +62,7 @@ fn main() {
         tile: matches.is_present("tile"),
         snap: matches.is_present("snap"),
         img: matches.is_present("img"),
+        hdmap: matches.is_present("hdmap"),
     };
 
     println!("Reading image files");
@@ -87,7 +89,7 @@ fn main() {
             if options.img {
                 Box::new(HeightmapFlat::new(colormap.size()).unwrap())
             } else {
-                match HeightmapPNG::new(heightmap_files) {
+                match HeightmapPNG::new(heightmap_files, options.hdmap) {
                     Ok(map) => Box::new(map),
                     Err(error) => {
                         return println!("Error reading colormap: {:?}", error);

src/map.rs

@@ -1,6 +1,8 @@
 extern crate image;
+extern crate byteorder;
 
-use image::RgbImage;
+use image::{RgbaImage, RgbImage};
+use byteorder::{ByteOrder, BigEndian};
 use std::result::Result;
 
 use crate::util::to_linear_rgb;
@@ -19,15 +21,22 @@ pub trait Colormap {
 
 // PNG based heightmaps
 pub struct HeightmapPNG {
-    maps: Vec<RgbImage>,
+    maps: Vec<RgbaImage>,
+    rgba_encoded: bool,
 }
 
 // Heightmap lookup
 impl Heightmap for HeightmapPNG {
     fn at(&self, x: u32, y: u32) -> u32 {
-        self.maps
+        if self.rgba_encoded {
+            self.maps
             .iter()
-            .fold(0, |sum, m| sum + m.get_pixel(x, y as u32).0[0] as u32)
+            .fold(0, |sum, m| sum + BigEndian::read_u32(&m.get_pixel(x, y).0))
+        } else {
+            self.maps
+            .iter()
+            .fold(0, |sum, m| sum + m.get_pixel(x, y).0[0] as u32)
+        }
     }
 
     fn size(&self) -> (u32, u32) {
@@ -37,16 +46,16 @@ impl Heightmap for HeightmapPNG {
 
 // Heightmap image input
 impl HeightmapPNG {
-    pub fn new(images: Vec<&str>) -> Result<Self, String> {
+    pub fn new(images: Vec<&str>, rgba_encoded:bool) -> Result<Self, String> {
         if images.is_empty() {
             return Err("HeightmapPNG requires at least one image".to_string());
         }
 
         // read in the maps
-        let mut maps: Vec<RgbImage> = vec![];
+        let mut maps: Vec<RgbaImage> = vec![];
         for file in images {
             if let Ok(img) = image::open(file) {
-                maps.push(img.to_rgb());
+                maps.push(img.to_rgba());
             } else {
                 return Err(format!("Could not open PNG {}", file));
             }
@@ -62,7 +71,7 @@ impl HeightmapPNG {
         }
 
         // return a reference to save on memory
-        Ok(HeightmapPNG { maps })
+        Ok(HeightmapPNG { maps, rgba_encoded })
     }
 }
 

src/util.rs

@@ -14,6 +14,7 @@ pub struct GenOptions {
     pub tile: bool,
     pub snap: bool,
     pub img: bool,
+    pub hdmap: bool,
 }
 
 // convert gamma to linear gamma