From 8cb751ff015271e1844feece5db2113eaec64af3 Mon Sep 17 00:00:00 2001
From: Frederico Linhares <fred@linhares.blue>
Date: Fri, 23 Jun 2023 20:45:23 -0300
Subject: feat Create an interface to read binary files

* test/meshes/cube.cgmesh: Store data using Big-Endian order.
---
 src/vk/qoi.cpp | 85 +++++++++++++++-------------------------------------------
 1 file changed, 22 insertions(+), 63 deletions(-)

(limited to 'src/vk/qoi.cpp')

diff --git a/src/vk/qoi.cpp b/src/vk/qoi.cpp
index 8b7ef9e..4e2b2a4 100644
--- a/src/vk/qoi.cpp
+++ b/src/vk/qoi.cpp
@@ -19,6 +19,8 @@
 #include <array>
 #include <fstream>
 
+#include "../binary_reader.hpp"
+
 namespace
 {
 
@@ -88,26 +90,6 @@ color_hash(const RGBA &colors)
   return colors.red*3 + colors.green*5 + colors.blue*7 + colors.alpha*11;
 }
 
-void
-read_chars(uint8_t *data, int &p, char *str, int size)
-{
-  for(int i{0}; i < size; i++) str[i] = (char)data[p++];
-}
-
-void
-read_ui8(uint8_t *data, int &p, uint8_t &num)
-{
-  num = data[p++];
-}
-
-void
-read_ui32(uint8_t *data, int &p, uint32_t &num)
-{
-  uint8_t b1{data[p++]}, b2{data[p++]}, b3{data[p++]}, b4{data[p++]};
-
-  num = b1 << 24 | b2 << 16 | b3 << 8 | b4;
-}
-
 }
 
 namespace VK::QOI
@@ -116,38 +98,22 @@ namespace VK::QOI
 Image::Image(const char *file_path, uint8_t channels):
   channels{channels}
 {
-  int data_p{0};
-  int data_size;
-  uint8_t *data;
-
   if(this->channels != 0 && this->channels != 3 && this->channels != 4)
   {
     throw std::invalid_argument{"invalid number of channels"};
   }
 
-  { // Read data from file.
-    std::ifstream file(file_path, std::ios::binary | std::ios::ate);
-    if(!file)
-    {
-      throw std::runtime_error{"failed to open QOI file"};
-    }
-
-    data_size = file.tellg();
-    if(data_size < HEADER_SIZE + (int)sizeof(PADDING))
-    {
-      throw std::runtime_error{"invalid QOI file"};
-    }
-
-    file.seekg(0);
-    data = new uint8_t[data_size];
-    file.read((char*)data, data_size);
+  BinaryReader input{file_path};
+  if(input.size() < HEADER_SIZE + (int)sizeof(PADDING))
+  {
+    throw std::runtime_error{"invalid QOI file"};
   }
 
-  read_chars(data, data_p, this->header.magic, 4);
-  read_ui32(data, data_p, this->header.width);
-  read_ui32(data, data_p, this->header.height);
-  read_ui8(data, data_p, this->header.channels);
-  read_ui8(data, data_p, this->header.colorspace);
+  input.read_chars(this->header.magic, 4);
+  this->header.width = input.read_ui32();
+  this->header.height = input.read_ui32();
+  this->header.channels = input.read_ui8();
+  this->header.colorspace = input.read_ui8();
 
   if(this->header.width == 0 || this->header.height == 0 ||
      this->header.channels < 3 || this->header.channels > 4 ||
@@ -165,7 +131,7 @@ Image::Image(const char *file_path, uint8_t channels):
 
   std::array<Pixel, 64> index;
   Pixel pixel{};
-  int chunks_len = data_size - (int)sizeof(PADDING);
+  int chunks_len = input.size() - (int)sizeof(PADDING);
 
   /*
     This algorithm is based on the original implementation that is in GitHub:
@@ -181,25 +147,22 @@ Image::Image(const char *file_path, uint8_t channels):
     {
       run--;
     }
-    else if(data_p < chunks_len)
+    else if(input.pointer() < chunks_len)
     {
-      uint8_t output;
-      int b1;
-      read_ui8(data, data_p, output);
-      b1 = output;
+      int b1 = input.read_ui8();
 
       if (b1 == OP_RGB)
       {
-        read_ui8(data, data_p, pixel.colors.red);
-        read_ui8(data, data_p, pixel.colors.green);
-        read_ui8(data, data_p, pixel.colors.blue);
+        pixel.colors.red = input.read_ui8();
+        pixel.colors.green = input.read_ui8();
+        pixel.colors.blue = input.read_ui8();
       }
       else if (b1 == OP_RGBA)
       {
-        read_ui8(data, data_p, pixel.colors.red);
-        read_ui8(data, data_p, pixel.colors.green);
-        read_ui8(data, data_p, pixel.colors.blue);
-        read_ui8(data, data_p, pixel.colors.alpha);
+        pixel.colors.red = input.read_ui8();
+        pixel.colors.green = input.read_ui8();
+        pixel.colors.blue = input.read_ui8();
+        pixel.colors.alpha = input.read_ui8();
       }
       else if ((b1 & MASK_2_BITS) == OP_INDEX)
       {
@@ -213,9 +176,7 @@ Image::Image(const char *file_path, uint8_t channels):
       }
       else if ((b1 & MASK_2_BITS) == OP_LUMA)
       {
-        int b2;
-        read_ui8(data, data_p, output);
-        b2 = output;
+        int b2 = input.read_ui8();
         int vg = (b1 & 0x3f) - 32;
         pixel.colors.red += vg - 8 + ((b2 >> 4) & 0x0f);
         pixel.colors.green += vg;
@@ -234,8 +195,6 @@ Image::Image(const char *file_path, uint8_t channels):
     this->pixels[pixel_p++] = pixel.colors.blue;
     if(this->channels == 4) this->pixels[pixel_p++] = pixel.colors.alpha;
   }
-
-  delete[] data;
 }
 
 Image::~Image()
-- 
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