From 797e30a9b3b99cce8c6da581457fa599c359b26f Mon Sep 17 00:00:00 2001
From: Alejandro Laguna <alejandro.laguna@proton.me>
Date: Wed, 15 Jul 2026 11:28:20 +0200
Subject: [PATCH] feat: show values on text

---
 include/mandelbrot.h |  2 +-
 src/main.c           | 14 +++++++++-----
 src/math.c           | 18 ++++++++++++++++++
 3 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/include/mandelbrot.h b/include/mandelbrot.h
index ad8375a8e46b20a0160df1155d5255da925e1c59..f377522b3c91469042dd6683e95f1b7d07ce1085 100644
--- a/include/mandelbrot.h
+++ b/include/mandelbrot.h
@@ -21,11 +21,11 @@ typedef struct position_s {
 // math.c
 int mandelbrot_iterations(double cr, double ci, int max_iter);
 void calculate_points(position_t* pos);
+void mandelbrot_at_point(double cr, double ci, int* iter_out, double* zr_out, double* zi_out);
 
 // draw.c
 // TODO: color struct or something
 void get_color(int iter, int max_iter, int* r, int* g, int* b);
 void draw_points(SDL_Surface* surface);
 
-
 #endif
diff --git a/src/main.c b/src/main.c
index 060df0405f5ef39ab9c6fa1203ea657007ea8f50..a7d755a2e6ba3769280753dc321c4721989db342 100644
--- a/src/main.c
+++ b/src/main.c
@@ -101,11 +101,15 @@ int main(void) {
                 }
                 float mx, my;
                 SDL_GetMouseState(&mx, &my);
-                int ix = (int)floor(mx);
-                int iy = (int)floor(my);
-                int iter = points[iy * WINDOW_WIDTH + ix];
-                snprintf(debug_text, sizeof(debug_text), "x: %d  y: %d  iterations: %d", ix, iy,
-                         iter);
+                double cr =
+                    position.x_min + (position.x_max - position.x_min) * mx / (WINDOW_WIDTH - 1);
+                double ci =
+                    position.y_min + (position.y_max - position.y_min) * my / (WINDOW_HEIGHT - 1);
+                int iter;
+                double zr, zi;
+                mandelbrot_at_point(cr, ci, &iter, &zr, &zi);
+                snprintf(debug_text, sizeof(debug_text),
+                         "c = %.6f %+.6fi | z = %.6f %+.6fi | iteration %d", cr, ci, zr, zi, iter);
             }
 
             if (e.type == SDL_EVENT_MOUSE_MOTION) {
diff --git a/src/math.c b/src/math.c
index d7e737810697a0d2d47b7ae900bf03475ad3cab8..dd28d90f99b124be6147f0da5aede1b3c10f4351 100644
--- a/src/math.c
+++ b/src/math.c
@@ -35,6 +35,24 @@ int mandelbrot_iterations(double cr, double ci, int max_iter) {
 
 extern int points[WINDOW_WIDTH * WINDOW_HEIGHT];
 
+void mandelbrot_at_point(double cr, double ci, int* iter_out, double* zr_out, double* zi_out) {
+    double zr = 0.0, zi = 0.0;
+    int iter = 0;
+    while (iter < 100) {
+        double zr2 = zr * zr;
+        double zi2 = zi * zi;
+        if (zr2 + zi2 > 4.0) {
+            break;
+        }
+        zi = 2.0 * zr * zi + ci;
+        zr = zr2 - zi2 + cr;
+        iter++;
+    }
+    *iter_out = iter;
+    *zr_out = zr;
+    *zi_out = zi;
+}
+
 void calculate_points(position_t* pos) {
     int max_iter = 100;
     for (int py = 0; py < WINDOW_HEIGHT; py++) {