From 10d387e036f217e4fc1041fa84da58632fc3f55e Mon Sep 17 00:00:00 2001
From: Muaz Ahmad <mahmad2000@protonmail.com>
Date: Mon, 4 Dec 2023 14:48:17 +0500
Subject: [PATCH] tmp

---
 src/output.zig | 91 +++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 76 insertions(+), 15 deletions(-)

diff --git a/src/output.zig b/src/output.zig
index 76fc9cd..df40b31 100644
--- a/src/output.zig
+++ b/src/output.zig
@@ -9,9 +9,14 @@ const RLE_Unit = struct {
 };
 
 const Huffman = std.AutoHashMap(u8, HuffCode);
-const HuffCode = struct {
-    n_bits: u8,
-    value: u16,
+// const HuffCode = struct {
+//     n_bits: u8,
+//     value: u16,
+// };
+const HuffCode = u16;
+const HuffmanMeta = struct {
+    bits: [33]u8,
+    huffval: [256]u8,
 };
 
 const Scan = struct {
@@ -20,23 +25,27 @@ const Scan = struct {
     dc_diffs: [3]i16,
     rles: [3]RLE_Seq,
     freqs: [4][]u32,
-    huffs: [4]Huffman,
+    huffs: [4]*Huffman,
 
     const Self = @This();
 
     fn init(alloc_root: std.mem.Allocator) !Self {
         var arena = std.heap.ArenaAllocator.init(alloc_root);
         var alloc = arena.allocator();
-        return Self{ .root_alloc = alloc_root, .arena = arena, .dc_diffs = [3]i16{ 0, 0, 0 }, .rles = [3]RLE_Seq{
+        var self = Self{ .root_alloc = alloc_root, .arena = arena, .dc_diffs = [3]i16{ 0, 0, 0 }, .rles = [3]RLE_Seq{
             RLE_Seq.init(alloc_root),
             RLE_Seq.init(alloc_root),
             RLE_Seq.init(alloc_root),
-        }, .freqs = [4][]u32{ try alloc.alloc(u32, 13), try alloc.alloc(u32, 257), try alloc.alloc(u32, 13), try alloc.alloc(u32, 257) }, .huffs = [4]Huffman{
-            Huffman.init(alloc),
-            Huffman.init(alloc),
-            Huffman.init(alloc),
-            Huffman.init(alloc),
+        }, .freqs = [4][]u32{ try alloc.alloc(u32, 13), try alloc.alloc(u32, 257), try alloc.alloc(u32, 13), try alloc.alloc(u32, 257) }, .huffs = [4]*Huffman{
+            try alloc.create(Huffman),
+            try alloc.create(Huffman),
+            try alloc.create(Huffman),
+            try alloc.create(Huffman),
         } };
+        for (0..4) |i| {
+            self.huffs[i].* = Huffman.init(alloc);
+        }
+        return self;
     }
     fn deinit(self: *Self) void {
         self.arena.deinit();
@@ -66,8 +75,12 @@ const Scan = struct {
     }
 
     fn generate_huffmans(self: *Self) !void {
-        for (0..4) |i| {
-            try gen_huffman(&self.huffs[i], self.freqs[i]);
+        for (0..4) |i_freq| {
+            const huffman_meta = gen_huffman(self.freqs[i_freq]);
+            _ = huffman_meta;
+            var huff = self.huffs[i_freq];
+            std.debug.print("{any}\n", .{huff});
+            try huff.put(0, 1);
         }
     }
 };
@@ -110,9 +123,54 @@ inline fn get_idx_min2(freqs: []u32) ?struct { usize, usize } {
     } else null;
 }
 
-inline fn gen_huffman(huff: *Huffman, freqs: []u32) !void {
+inline fn gen_codes(huff: *Huffman, huffman_meta: HuffmanMeta) !void {
+    var huffsize = [_]u5{0} ** 256;
+    var huffcode = [_]u16{0} ** 256;
+
+    var k: usize = 0;
+    var j: usize = 0;
+    for (0..17) |i| {
+        while (j <= huffman_meta.bits[i]) {
+            huffsize[k] = @truncate(i);
+            k += 1;
+            j += 1;
+        }
+        j = 1;
+    }
+    huffsize[k] = 0;
+    const total_k = k + 1;
+
+    k = 0;
+    var code: usize = 0;
+    var si = huffsize[0];
+    while (true) {
+        huffcode[k] = @truncate(code);
+        code += 1;
+        k += 1;
+        if (huffsize[k] == si) {
+            continue;
+        }
+        if (huffsize[k] == 0) {
+            break;
+        }
+        code <<= 1;
+        si += 1;
+        while (huffsize[k] != si) {
+            code <<= 1;
+            si += 1;
+        }
+    }
+
+    for (0..total_k) |x| {
+        try huff.put(@truncate(x), HuffCode{
+            .n_bits = huffsize[x],
+            .value = huffcode[x],
+        });
+    }
+}
+
+inline fn gen_huffman(freqs: []u32) HuffmanMeta {
     freqs[freqs.len - 1] = 1;
-    _ = huff;
     var codesizes = [_]u8{0} ** 257;
     var others = [_]u9{0x1ff} ** 257;
     while (get_idx_min2(freqs)) |tmp| {
@@ -166,7 +224,10 @@ inline fn gen_huffman(huff: *Huffman, freqs: []u32) !void {
         }
     }
 
-    std.debug.print("{any}\n{any}\n\n", .{ bits, huffval });
+    return .{
+        .bits = bits,
+        .huffval = huffval,
+    };
 }
 
 inline fn get_size(n: i16) u8 {