visualization cooler a bit. but still not great

travaux_pratiques/tpChaos/Makefile

 CC=gcc
-CFLAGS=-Wall -Wextra -pedantic -std=c11 -g -fsanitize=leak -fsanitize=undefined  -fsanitize=address -O3
+CFLAGS=-Wall -Wextra -pedantic -std=c11 -g -O3
+# -fsanitize=leak -fsanitize=undefined  -fsanitize=address
 LFLAGS=-lSDL2
 TARGET=map
 

travaux_pratiques/tpChaos/map.c

@@ -3,16 +3,24 @@
 #include <unistd.h>
 #include "gfx.h"
 
-double map(double x, double lambda) {
+static void gfx_clear_rect(struct gfx_context_t *ctxt, int x0, int x1, int y0, int y1) {
+    for (int x = x0; x < x1; ++x) {
+        for (int y = y0; y < y1; ++y) {
+            gfx_putpixel(ctxt, x, y, COLOR_BLACK);
+        }
+    }
+}
+
+static double map(double x, double lambda) {
     return lambda * x * (1.0 - x);
 }
 
 int main() {
-    const double lambda_min = 0;
+    const double lambda_min = 3;
     const double lambda_max = 4;
     const int N = 1920;
-    const int M = 960;
-    const double dl = (lambda_max - lambda_min) / N;
+    const int M = 1000;
+    double dl = (lambda_max - lambda_min) / N;
 
     struct gfx_context_t *ctxt = gfx_create("Example", N, M);
 	if (!ctxt) {
@@ -20,25 +28,38 @@ int main() {
 		return EXIT_FAILURE;
 	}
     gfx_clear(ctxt, COLOR_BLACK);
+
+    double prop = 0.2;
+    int num_points = M / 10;
     
-    int max_iter = 100000;
-    for (double i_lambda = 0; i_lambda < N; ++i_lambda) {
+    int max_iter = 10000;
+    for (int i_lambda = 0; i_lambda < N; ++i_lambda) {
         double x = 0.5;
         for (int i = 0; i < max_iter; ++i) {
             double lambda = lambda_min + i_lambda * dl;
-            double x_new = map(x, lambda);
-            x = x_new;
-            if (i > max_iter - M) {
-		        gfx_putpixel(ctxt, i_lambda, M - x * M - 1, COLOR_WHITE);
+            x = map(x, lambda);
+            if (i > max_iter - num_points) {
+                gfx_putpixel(ctxt, i % (num_points / 2), (M - 1) - (M - 1) * x * prop, COLOR_WHITE);
+                gfx_clear_rect(ctxt, (i + 1) % (num_points / 2), (i + 2) % (num_points / 2), (1 - prop) * (M-1), (M - 1));
+                
+		        gfx_putpixel(ctxt, i_lambda, (M - 1) * (1 - x), COLOR_WHITE);
                 // printf("x(%d, %g) = %g\n", i, i_lambda * dl, x);
 
                 // usleep((unsigned int)1000);
+                
+                // if (i % 512 == 0) {
+                //     gfx_present(ctxt);
+                // }
+
             }
+
         }
+        gfx_clear_rect(ctxt, (num_points / 2 - 1), (num_points / 2) + 2, (1 - prop) * (M-1), (M - 1));
         gfx_present(ctxt);
 
         // printf("\n");
     }
+
     while (gfx_keypressed() != SDLK_ESCAPE) {
 	}