From 8a9d0286ef441a8ef0ba6865da9c419ea2b988b2 Mon Sep 17 00:00:00 2001
From: Simon Hardt <s-hardt@live.de>
Date: Thu, 3 Mar 2022 21:47:35 +0100
Subject: [PATCH] fix midpoint

---
 CMakeLists.txt                    |  2 +-
 frame/src/main.cpp                | 31 ++++++-----------------
 frame/src/render/RenderTarget.cpp | 41 +++++++++++++++++++++++--------
 3 files changed, 39 insertions(+), 35 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b476f13..a258284 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.20)
+cmake_minimum_required(VERSION 3.18)
 
 project(Frame)
 
diff --git a/frame/src/main.cpp b/frame/src/main.cpp
index 6310f24..edd52be 100644
--- a/frame/src/main.cpp
+++ b/frame/src/main.cpp
@@ -1,8 +1,8 @@
+#include <cmath>
 #include <chrono>
 #include <iostream>
 #include <thread>
 #include <vector>
-#include <cmath>
 
 using namespace std::chrono_literals;
 
@@ -12,17 +12,8 @@ using namespace std::chrono_literals;
 
 int main()
 {
-    double const pi = 3.14159;
+    constexpr double pi = 3.14159;
 
-    std::cout << "pi: " << pi << " " << 3.14159f << std::endl;
-    std::cout << "pi / 180;"  << pi / 180.f << std::endl;
-    for(int i = 0; i < 360; i += 45)
-    {
-        std::cout << "(i): " << i << std::endl;
-        std::cout << "rad: " << (float)i * pi / 180.f << std::endl;
-    }
-
-    return 0;
 
     frame::display::EPD_7in5_V2 display{};
 
@@ -34,28 +25,20 @@ int main()
 
     frame::Vector const center = (display.getSize() / 2);
 
-    frame::Vector v = {10, 12};
-    std::cout << "Main: " << v << std::endl;
 
     target.DrawPixel({10, 10}, frame::BLACK);
-    target.DrawLine(v, {100, 12}, frame::BLACK);
+    target.DrawLine({10, 12}, {100, 12}, frame::BLACK);
 
-    for(int i = 0; i < 360; i += 45)
+    for(int i = 0; i < 360; i += 15)
     {
         auto end = center;
 
-	double const cos_ = i * 0.01745329;
-	std::cout << i << " cos: " << cos_ << std::endl;
-	double x = std::cos(cos_);
-        double y = std::sin(i * 0.01745329);
-	x *= 50.f;
-        y *= 50.f;
-        std::cout << x << " " << (int)x << " " << y << std::endl;
+	double const x = std::cos(i * pi / 180.f) * 200.f;
+        double const y = std::sin(i * pi / 180.f) * 200.f;
+
         end.x += (int)x;
         end.y += (int)y;
 
-
-	std::cout << end << std::endl;
         target.DrawLine(center, end);
     }
 
diff --git a/frame/src/render/RenderTarget.cpp b/frame/src/render/RenderTarget.cpp
index 850fcdf..3483591 100644
--- a/frame/src/render/RenderTarget.cpp
+++ b/frame/src/render/RenderTarget.cpp
@@ -1,7 +1,6 @@
 #include "RenderTarget.hpp"
 
 #include <cmath>
-#include <iostream>
 
 namespace frame::render
 {
@@ -20,33 +19,55 @@ namespace frame::render
                                 Vector const& end,
                                 Color color)
     {
-        auto const deltaX = std::abs(start.x - end.x);
-        auto const deltaY = std::abs(start.y - end.y);
+        auto deltaX = std::abs(start.x - end.x);
+        auto deltaY = std::abs(start.y - end.y);
 
-        auto const rX = start.x < end.x ? 1 : -1;
-        auto const rY = start.y < end.y ? 1 : -1;
+        auto rX = start.x < end.x ? 1 : -1;
+        auto rY = start.y < end.y ? 1 : -1;
+
+        bool swap = false;
+
+        if(deltaX < deltaY)
+        {
+            swap = true;
+            std::swap(deltaX, deltaY);
+            std::swap(rX, rY);
+        }
 
         auto pos = start;
         auto E   = 2 * deltaY - deltaX;
 
-        std::cout << "Start: " << start << " End: " << end << std::endl;
         DrawPixel(pos, color);
 
         while(pos != end)
         {
             if(E <= 0)
             {
-                pos.x += rX;
+                if(!swap)
+                    pos.x += rX;
+                else
+                    pos.y += rX;
 
                 E += 2 * deltaY;
             } else
             {
-                pos.x += rX;
-                pos.y += rY;
+                if(!swap)
+                {
+                    pos.x += rX;
+                    pos.y += rY;
+                }
+                else
+                {
+                    pos.y += rX;
+                    pos.x += rY;
+                }
 
                 E += 2 * deltaY - 2 * deltaX;
             }
-            std::cout << pos << std::endl;
+
+            if(pos.x < 0 || pos.y < 0 || pos.x >= image.getWidth() || pos.y >= image.getHeight())
+                break;
+
             DrawPixel(pos, color);
         }
     }