Update small code issues for triangles

6 files changed, 53 insertions, 52 deletions

diff --git a/.gitignore b/.gitignore
index d5a1572..1d148d4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 *.swp
 build
+in_progress
diff --git a/html/feed.xml b/html/feed.xml
index 5bae95e..a526b2c 100644
--- a/html/feed.xml
+++ b/html/feed.xml
@@ -1,5 +1,5 @@
 <?xml version='1.0' encoding='UTF-8'?>
-<rss xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title>Fryzek Concepts</title><atom:link href="https://fryzekconcepts.com/feed.xml" rel="self" type="application/rss+xml"/><link>https://fryzekconcepts.com</link><description>Lucas is a developer working on cool things</description><lastBuildDate>Sat, 11 Feb 2023 16:49:59 -0000</lastBuildDate><item><title>Generating Video</title><link>https://fryzekconcepts.com/notes/generating-video.html</link><description>&lt;p&gt;One thing I’m very interested in is computer graphics. This could be complex 3D graphics or simple 2D graphics. The idea of getting a computer to display visual data fascinates me. One fundamental part of showing visual data is interfacing with a computer monitor. This can be accomplished by generating a video signal that the monitor understands. Below I have written instructions on how an FPGA can be used to generate a video signal. I have specifically worked with the iCEBreaker FPGA but the theory contained within this should work with any FPGA or device that you can generate the appropriate timings for.&lt;/p&gt;
+<rss xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title>Fryzek Concepts</title><atom:link href="https://fryzekconcepts.com/feed.xml" rel="self" type="application/rss+xml"/><link>https://fryzekconcepts.com</link><description>Lucas is a developer working on cool things</description><lastBuildDate>Mon, 20 Feb 2023 19:31:26 -0000</lastBuildDate><item><title>Generating Video</title><link>https://fryzekconcepts.com/notes/generating-video.html</link><description>&lt;p&gt;One thing I’m very interested in is computer graphics. This could be complex 3D graphics or simple 2D graphics. The idea of getting a computer to display visual data fascinates me. One fundamental part of showing visual data is interfacing with a computer monitor. This can be accomplished by generating a video signal that the monitor understands. Below I have written instructions on how an FPGA can be used to generate a video signal. I have specifically worked with the iCEBreaker FPGA but the theory contained within this should work with any FPGA or device that you can generate the appropriate timings for.&lt;/p&gt;
 &lt;h3 id="tools"&gt;Tools&lt;/h3&gt;
 &lt;p&gt;Hardware used (&lt;a href="https://www.crowdsupply.com/1bitsquared/icebreaker-fpga"&gt;link for board&lt;/a&gt;):&lt;/p&gt;
 &lt;ul&gt;
@@ -505,7 +505,7 @@ Value(x, y+1) = Value(x,y) - dXV&lt;/code&gt;&lt;/pre&gt;
 func draw_triangle(x0, y0, x1, y1, x2, y2, v0, v1, v2):
     dX0 = x0 - x2
     dX1 = x1 - x0
-    dX2 = x2 - x2
+    dX2 = x2 - x1
     dY0 = y0 - y2
     dY1 = y1 - y0
     dY2 = y2 - y1
@@ -529,20 +529,20 @@ func draw_triangle(x0, y0, x1, y1, x2, y2, v0, v1, v2):
         for x = 0 to screen_width:
             if(e0 &amp;gt;= 0 &amp;amp;&amp;amp; e1 &amp;gt;= 0 &amp;amp;&amp;amp; e2 &amp;gt;= 0)
                 draw_pixel(x, y, v)
-        e0 = e0 + dY0
-        e1 = e1 + dY1
-        e2 = e2 + dY2
-        v = v + dYV
+            e0 = e0 + dY0
+            e1 = e1 + dY1
+            e2 = e2 + dY2
+            v = v + dYV
 
-    e0 = starting_e0 - dX0
-    e1 = starting_e1 - dX1
-    e2 = starting_e2 - dX2
-    v = starting_v - dXV
+        e0 = starting_e0 - dX0
+        e1 = starting_e1 - dX1
+        e2 = starting_e2 - dX2
+        v = starting_v - dXV
 
-    starting_e0 = e0
-    starting_e1 = e1
-    starting_e2 = e2
-    starting_v = v&lt;/code&gt;&lt;/pre&gt;
+        starting_e0 = e0
+        starting_e1 = e1
+        starting_e2 = e2
+        starting_v = v&lt;/code&gt;&lt;/pre&gt;
 &lt;p&gt;Now this pseudo code is not the most efficient as it will iterate over the entire screen to draw one triangle, but it provides a starting basis to show how to use these Pineda properties to calculate per vertex values. One thing to note if you do implement this is, if you use fixed point arithmetic, be careful to insure you have enough precision to calculate all of these values with overflow or underflow. This was an issue I ran into running out of precision when I did the divide by the area.&lt;/p&gt;
 </description><pubDate>Sun, 03 Apr 2022 04:00:00 -0000</pubDate><guid>https://fryzekconcepts.com/notes/rasterizing-triangles.html</guid></item><item><title>Baremetal RISC-V</title><link>https://fryzekconcepts.com/notes/baremetal-risc-v.html</link><description>&lt;p&gt;After re-watching suckerpinch’s &lt;a href="https://www.youtube.com/watch?v=ar9WRwCiSr0"&gt;“Reverse Emulation”&lt;/a&gt; video I got inspired to try and replicate what he did, but instead do it on an N64. Now my idea here is not to preform reverse emulation on the N64 itself but instead to use the SBC as a cheap way to make a dev focused flash cart. Seeing that sukerpinch was able to meet the timings of the NES bus made me think it might be possible to meet the N64 bus timings taking an approach similar to his.&lt;/p&gt;
 &lt;h2 id="why-risc-v-baremetal"&gt;Why RISC-V Baremetal?&lt;/h2&gt;
diff --git a/html/graphics_feed.xml b/html/graphics_feed.xml
index 3afd922..9aa1ca6 100644
--- a/html/graphics_feed.xml
+++ b/html/graphics_feed.xml
@@ -1,5 +1,5 @@
 <?xml version='1.0' encoding='UTF-8'?>
-<rss xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title>Fryzek Concepts</title><atom:link href="https://fryzekconcepts.com/feed.xml" rel="self" type="application/rss+xml"/><link>https://fryzekconcepts.com</link><description>Lucas is a developer working on cool things</description><lastBuildDate>Sat, 11 Feb 2023 16:50:00 -0000</lastBuildDate><item><title>2022 Graphics Team Contributions at Igalia</title><link>https://fryzekconcepts.com/notes/2022_igalia_graphics_team.html</link><description>&lt;p&gt;This year I started a new job working with &lt;a href="https://www.igalia.com/technology/graphics"&gt;Igalia’s Graphics Team&lt;/a&gt;. For those of you who don’t know &lt;a href="https://www.igalia.com/"&gt;Igalia&lt;/a&gt; they are a &lt;a href="https://en.wikipedia.org/wiki/Igalia"&gt;“worker-owned, employee-run cooperative model consultancy focused on open source software”&lt;/a&gt;.&lt;/p&gt;
+<rss xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title>Fryzek Concepts</title><atom:link href="https://fryzekconcepts.com/feed.xml" rel="self" type="application/rss+xml"/><link>https://fryzekconcepts.com</link><description>Lucas is a developer working on cool things</description><lastBuildDate>Mon, 20 Feb 2023 19:31:26 -0000</lastBuildDate><item><title>2022 Graphics Team Contributions at Igalia</title><link>https://fryzekconcepts.com/notes/2022_igalia_graphics_team.html</link><description>&lt;p&gt;This year I started a new job working with &lt;a href="https://www.igalia.com/technology/graphics"&gt;Igalia’s Graphics Team&lt;/a&gt;. For those of you who don’t know &lt;a href="https://www.igalia.com/"&gt;Igalia&lt;/a&gt; they are a &lt;a href="https://en.wikipedia.org/wiki/Igalia"&gt;“worker-owned, employee-run cooperative model consultancy focused on open source software”&lt;/a&gt;.&lt;/p&gt;
 &lt;p&gt;As a new member of the team, I thought it would be a great idea to summarize the incredible amount of work the team completed in 2022. If you’re interested keep reading!&lt;/p&gt;
 &lt;h2 id="vulkan-1.2-conformance-on-rpi-4"&gt;Vulkan 1.2 Conformance on RPi 4&lt;/h2&gt;
 &lt;p&gt;One of the big milestones for the team in 2022 was &lt;a href="https://www.khronos.org/conformance/adopters/conformant-products#submission_694"&gt;achieving Vulkan 1.2 conformance on the Raspberry Pi 4&lt;/a&gt;. The folks over at the Raspberry Pi company wrote a nice &lt;a href="https://www.raspberrypi.com/news/vulkan-update-version-1-2-conformance-for-raspberry-pi-4/"&gt;article&lt;/a&gt; about the achievement. Igalia has been partnering with the Raspberry Pi company to bring build and improve the graphics driver on all versions of the Raspberry Pi.&lt;/p&gt;
diff --git a/html/index.html b/html/index.html
index be2f68c..bf37882 100644
--- a/html/index.html
+++ b/html/index.html
@@ -44,6 +44,13 @@
     </a>
 </h2>
 <div class="notes-container">
+        <a href="/notes/rasterizing-triangles.html" class="note-link">
+        <div class="note-box">
+            <img src="/assets/2022-04-03-rasterizing-triangles/Screenshot-from-2022-04-03-13-43-13.png">
+            <h2>Rasterizing Triangles</h2>
+            <p>Lately I’ve been trying to implement a software renderer following the algorithm described by                                                                                                                                                                                                                                                                                                                                                                                                                    ...</p>
+        </div>
+    </a>
         <a href="/notes/global_game_jam_2023.html" class="note-link">
         <div class="note-box">
             <img src="/assets/global_game_jam_2023/screen_shot_2.png">
@@ -71,13 +78,6 @@
             <p>After reading Maggie Appleton page on digital gardens I was inspired to convert my own website into a digital garden.I have many half baked ideas that I seem to be able to finish. Some of them get to a published state like  and , but many of them never make it to the published state. The idea of digital garden seems very appealing to me, as it encourages you to post on a topic even if you haven’t made it publishable yet.How this site works - I wanted a bit of challenge when putting together  ...</p>
         </div>
     </a>
-        <a href="/notes/rasterizing-triangles.html" class="note-link">
-        <div class="note-box">
-            <img src="/assets/2022-04-03-rasterizing-triangles/Screenshot-from-2022-04-03-13-43-13.png">
-            <h2>Rasterizing Triangles</h2>
-            <p>Lately I’ve been trying to implement a software renderer following the algorithm described by                                                                                                                                                                                                                                                                                                                                                                                                                    ...</p>
-        </div>
-    </a>
         <a href="/notes/baremetal-risc-v.html" class="note-link">
         <div class="note-box">
             <img src="/assets/2022-06-09-baremetal-risc-v/PXL_20220609_121350403.jpg">
diff --git a/html/notes/rasterizing-triangles.html b/html/notes/rasterizing-triangles.html
index 69c05b3..a7756ec 100644
--- a/html/notes/rasterizing-triangles.html
+++ b/html/notes/rasterizing-triangles.html
@@ -35,7 +35,7 @@
                     </div>
                 <div class="page-info-date-container">
             <p class="page-info-date">Published: 2022-04-03</p>
-            <p class="page-info-date">Last Edited: 2022-10-30</p>
+            <p class="page-info-date">Last Edited: 2023-02-20</p>
         </div>
     </div>
     </div>
@@ -84,7 +84,7 @@ Value(x, y+1) = Value(x,y) - dXV</code></pre>
 func draw_triangle(x0, y0, x1, y1, x2, y2, v0, v1, v2):
     dX0 = x0 - x2
     dX1 = x1 - x0
-    dX2 = x2 - x2
+    dX2 = x2 - x1
     dY0 = y0 - y2
     dY1 = y1 - y0
     dY2 = y2 - y1
@@ -108,20 +108,20 @@ func draw_triangle(x0, y0, x1, y1, x2, y2, v0, v1, v2):
         for x = 0 to screen_width:
             if(e0 &gt;= 0 &amp;&amp; e1 &gt;= 0 &amp;&amp; e2 &gt;= 0)
                 draw_pixel(x, y, v)
-        e0 = e0 + dY0
-        e1 = e1 + dY1
-        e2 = e2 + dY2
-        v = v + dYV
+            e0 = e0 + dY0
+            e1 = e1 + dY1
+            e2 = e2 + dY2
+            v = v + dYV
 
-    e0 = starting_e0 - dX0
-    e1 = starting_e1 - dX1
-    e2 = starting_e2 - dX2
-    v = starting_v - dXV
+        e0 = starting_e0 - dX0
+        e1 = starting_e1 - dX1
+        e2 = starting_e2 - dX2
+        v = starting_v - dXV
 
-    starting_e0 = e0
-    starting_e1 = e1
-    starting_e2 = e2
-    starting_v = v</code></pre>
+        starting_e0 = e0
+        starting_e1 = e1
+        starting_e2 = e2
+        starting_v = v</code></pre>
 <p>Now this pseudo code is not the most efficient as it will iterate over the entire screen to draw one triangle, but it provides a starting basis to show how to use these Pineda properties to calculate per vertex values. One thing to note if you do implement this is, if you use fixed point arithmetic, be careful to insure you have enough precision to calculate all of these values with overflow or underflow. This was an issue I ran into running out of precision when I did the divide by the area.</p>
     </div>
 </div>    </main>
diff --git a/notes/rasterizing-triangles.md b/notes/rasterizing-triangles.md
index 354c4fa..73acb33 100644
--- a/notes/rasterizing-triangles.md
+++ b/notes/rasterizing-triangles.md
@@ -1,7 +1,7 @@
 ---
 title: "Rasterizing Triangles"
 date: "2022-04-03"
-last_edit: "2022-10-30"
+last_edit: "2023-02-20"
 status: 2
 cover_image: "/assets/2022-04-03-rasterizing-triangles/Screenshot-from-2022-04-03-13-43-13.png"
 ---
@@ -72,7 +72,7 @@ func edge(x, y, xi, yi, dXi, dYi)
 func draw_triangle(x0, y0, x1, y1, x2, y2, v0, v1, v2):
     dX0 = x0 - x2
     dX1 = x1 - x0
-    dX2 = x2 - x2
+    dX2 = x2 - x1
     dY0 = y0 - y2
     dY1 = y1 - y0
     dY2 = y2 - y1
@@ -96,20 +96,20 @@ func draw_triangle(x0, y0, x1, y1, x2, y2, v0, v1, v2):
         for x = 0 to screen_width:
             if(e0 >= 0 && e1 >= 0 && e2 >= 0)
                 draw_pixel(x, y, v)
-        e0 = e0 + dY0
-        e1 = e1 + dY1
-        e2 = e2 + dY2
-        v = v + dYV
-
-    e0 = starting_e0 - dX0
-    e1 = starting_e1 - dX1
-    e2 = starting_e2 - dX2
-    v = starting_v - dXV
-
-    starting_e0 = e0
-    starting_e1 = e1
-    starting_e2 = e2
-    starting_v = v
+            e0 = e0 + dY0
+            e1 = e1 + dY1
+            e2 = e2 + dY2
+            v = v + dYV
+
+        e0 = starting_e0 - dX0
+        e1 = starting_e1 - dX1
+        e2 = starting_e2 - dX2
+        v = starting_v - dXV
+
+        starting_e0 = e0
+        starting_e1 = e1
+        starting_e2 = e2
+        starting_v = v
 ```
 
 Now this pseudo code is not the most efficient as it will iterate over the entire screen to draw one triangle, but it provides a starting basis to show how to use these Pineda properties to calculate per vertex values. One thing to note if you do implement this is, if you use fixed point arithmetic, be careful to insure you have enough precision to calculate all of these values with overflow or underflow. This was an issue I ran into running out of precision when I did the divide by the area.