From 434eddee27aeff4198970b858c874a265939d50d Mon Sep 17 00:00:00 2001
From: jb <jason.d.baker@gmail.com>
Date: Tue, 8 Jul 2025 22:40:11 -0700
Subject: [PATCH] triangle midpoints

---
 scripts/main.c     | 15 ++++++++++--
 scripts/triangle.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++
 scripts/triangle.h |  2 ++
 3 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/scripts/main.c b/scripts/main.c
index 68abd5c..70261ac 100644
--- a/scripts/main.c
+++ b/scripts/main.c
@@ -153,6 +153,9 @@ void update(void) {
             projected_triangle.points[j] = projected_point;
         }
 
+        //vec2_t midpoint = triangle_midpoint(projected_triangle);
+        //draw_rect(midpoint.x, midpoint.y, 10, 10, 0xFFFF0000);
+
         // save the projected triangle in the array of triangles
         array_push(triangles_to_render, projected_triangle);
 
@@ -178,13 +181,21 @@ void render(void) {
     draw_grid();
 
     // Loop all projected points and render them
-    for (int i = 0; i < array_length(triangles_to_render); i++) {
+    /*for (int i = 0; i < array_length(triangles_to_render); i++) {
         triangle_t triangle = triangles_to_render[i];
         draw_triangle(triangle, 0xFF00FF00);
         draw_rect(triangle.points[0].x, triangle.points[0].y, 3, 3, 0xFFFFFF00);
         draw_rect(triangle.points[1].x, triangle.points[1].y, 3, 3, 0xFFFFFF00);
         draw_rect(triangle.points[2].x, triangle.points[2].y, 3, 3, 0xFFFFFF00);
-    }
+    }*/
+    triangle_t t;
+    t.points[0] = (vec2_t){ .x = 300, .y = 100 };
+    t.points[1] = (vec2_t){ .x = 50, .y = 400 };
+    t.points[2] = (vec2_t){ .x = 500, .y = 700 };
+
+    //draw_triangle(t, 0xFF00FF00);
+    vec2_t m = triangle_midpoint(t);
+    //draw_rect(m.x, m.y, 10, 10, 0xFFFF0000);
 
     //draw_line(10, 10, 500, 500, 0x00FF00);
     array_free(triangles_to_render);
diff --git a/scripts/triangle.c b/scripts/triangle.c
index 9b06023..a9d8885 100644
--- a/scripts/triangle.c
+++ b/scripts/triangle.c
@@ -1,3 +1,61 @@
 #include "triangle.h"
 
+#include "display.h"
+
 // TODO: Create implementation for triangle.h functions
+int compare_vec2_t(const void* a, const void* b) {
+    const vec2_t* arg1 = (const vec2_t*)a;
+    const vec2_t* arg2 = (const vec2_t*)b;
+    if (arg1->y < arg2->y) return -1;
+    if (arg1->y > arg2->y) return 1;
+    return 0;
+}
+
+void fill_flat_bottom_triangle(triangle_t triangle) {
+
+}
+
+void fill_flat_top_triangle(triangle_t triangle) {
+
+}
+
+vec2_t triangle_midpoint(triangle_t triangle) {
+    // sort by y
+    int temp = 0, min_idx = 0, mid_idx = 1, max_idx = 2;
+
+    if (triangle.points[min_idx].y > triangle.points[mid_idx].y) {
+        temp = min_idx; min_idx = mid_idx; mid_idx = temp;
+    }
+    if (triangle.points[min_idx].y > triangle.points[max_idx].y) {
+        temp = min_idx; min_idx = max_idx; max_idx = temp;
+    }
+    if (triangle.points[mid_idx].y > triangle.points[max_idx].y) {
+        temp = mid_idx; mid_idx = max_idx; max_idx = temp;
+    }
+
+    // check for division by zero
+    if (triangle.points[max_idx].y == triangle.points[min_idx].y) {
+        // Degenerate case, return something reasonable
+        return triangle.points[mid_idx];  // or some fallback
+    }
+
+    vec2_t midpoint;
+    midpoint.y = triangle.points[mid_idx].y;
+    midpoint.x = (((triangle.points[max_idx].x - triangle.points[min_idx].x) * (triangle.points[mid_idx].y - triangle.points[min_idx].y)) / (triangle.points[max_idx].y - triangle.points[min_idx].y)) + triangle.points[min_idx].x;
+
+    triangle_t flat_top, flat_bottom;
+
+    flat_bottom.points[0] = triangle.points[min_idx];
+    flat_bottom.points[1] = triangle.points[mid_idx];
+    flat_bottom.points[2] = midpoint;
+
+    flat_top.points[0] = triangle.points[mid_idx];
+    flat_top.points[1] = triangle.points[max_idx];
+    flat_top.points[2] = midpoint;
+
+    draw_triangle(flat_bottom, 0xFF00FF00);
+    draw_triangle(flat_top, 0xF0000FF);
+
+    return midpoint;
+
+}
\ No newline at end of file
diff --git a/scripts/triangle.h b/scripts/triangle.h
index 7b3e057..234c1b4 100644
--- a/scripts/triangle.h
+++ b/scripts/triangle.h
@@ -13,4 +13,6 @@ typedef struct {
     vec2_t points[3];
 } triangle_t;
 
+vec2_t triangle_midpoint(triangle_t triangle);
+
 #endif