generic attractor wip

CMakeLists.txt

@@ -68,6 +68,7 @@ add_library(clouds OBJECT
     acidwarp.cpp
     acidworm.cpp
     hopalong.cpp
+    attractor.cpp
     )
 
 target_include_directories(clouds PRIVATE .)

art.cpp

@@ -65,6 +65,8 @@ void Art::clear() {
     fill0(m_pixels);
     pixels_drawn = 0;
     pixels_discarded = 0;
+    if (pb)
+        pb->buffer.clear();
 }
 
 void Art::render_pixel_buffer(uint32_t* screen) {

artfactory.cpp

@@ -11,6 +11,7 @@
 #include "acidwarp.h"
 #include "acidworm.h"
 #include "hopalong.h"
+#include "attractor.h"
 
 
 ArtFactory::ArtFactory() {
@@ -25,6 +26,7 @@ ArtFactory::ArtFactory() {
     add_art<AcidWarp>("AcidWarp");
     add_art<AcidWorm>("AcidWorm");
     add_art<Hopalong>("Hopalong");
+    add_art<Attractor>("Attractor");
 
     vc = VectorCombo("Art", art_items);
     vc.set_index(1);

attractor.cpp

@@ -0,0 +1,104 @@
+
+#include "imgui_elements.h"
+#include "attractor.h"
+#include "random.h"
+// from yarandom.h
+#define LRAND()         ((long) (xoshiro256plus() & 0x7fffffff))
+#define MAXRAND         (2147483648.0) /* unsigned 1<<31 as a float */
+#define balance_rand(v)	((LRAND()/MAXRAND*(v))-((v)/2))	/* random around 0 */
+
+#include <math.h>
+
+// https://examples.holoviz.org/attractors/attractors.html
+
+void Attractor::init()
+{
+	int centerx, centery;
+	centerx = w / 2;
+	centery = h / 2;
+
+	double range = sqrt((double) centerx * centerx +
+	     (double) centery * centery) / (1.0 + LRAND() / MAXRAND);
+	ai = aj = 0.0;
+	/*
+	inc = (int) ((LRAND() / MAXRAND) * 200) - 100;
+	a = ((LRAND() / MAXRAND) * 2.0 - 1.0) * range / 20.0;
+	b = ((LRAND() / MAXRAND) * 2.0 - 1.0) * range / 20.0;
+	if (LRAND() & 1)
+		c = ((LRAND() / MAXRAND) * 2.0 - 1.0) * range / 20.0;
+	else
+		c = 0.0;
+	*/
+}
+
+
+void Attractor::draw()
+{
+
+}
+
+
+bool Attractor::render(uint32_t *p)
+{
+	int points_per_frame = 1024*128;
+	int x, y;
+	double oldi, oldj;
+
+	for (int i=0; i < points_per_frame && count < pixel_buffer_maximum; ++i, ++count) {
+		oldj = aj;
+		oldi = ai + inc;
+		aj = a - ai;
+		ai = oldj + (ai < 0
+					    ?  sqrt(fabs(b * oldi - c))
+					    : -sqrt(fabs(b * oldi - c))
+					);
+		x = w/2 + (int) (ai + aj);
+		y = h/2 - (int) (ai - aj);
+
+		drawdot(x, y, pal.get_color((pixel_buffer_maximum - count)>>2));
+	}
+
+	return false;
+}
+
+
+bool Attractor::render_gui ()
+{
+	bool up = false;
+
+	//up |= ScrollableSliderInt("op", &op, 0, 10, "%d", 1);
+	/*
+	if (ScrollableSliderInt("iterations kcount", &kcount, 0, 1024, "%d", 1)) {
+		count = kcount * 1024;
+		pal.rescale(count >> 1);
+	}
+	*/
+
+	up |= ScrollableSliderDouble("inc", &inc, -200, 200, "%.4f", 0.0001);
+	up |= ScrollableSliderDouble("a", &a, -20, 20, "%.4f", 0.000001);
+	up |= ScrollableSliderDouble("b", &b, -20, 20, "%.4f", 0.000001);
+	up |= ScrollableSliderDouble("c", &c, -20, 20, "%.4f", 0.000001);
+	up |= ScrollableSliderDouble("d", &d, -20, 20, "%.4f", 0.000001);
+
+
+	up |= pal.RenderGui();
+
+	//ImGui::Text("count %d, op %d", count, op);
+
+
+	if (up) {
+		resize(w, h);
+	}
+
+	return false;
+}
+
+void Attractor::resize(int _w, int _h) {
+	default_resize(_w, _h);
+
+	pal.rescale(pixel_buffer_maximum >> 2);
+	count = 0;
+
+	//clear();
+	init();
+}

attractor.h

@@ -0,0 +1,32 @@
+#include "art.hpp"
+#include "imgui.h"
+#include <vector>
+
+#include "settings.hpp"
+
+
+
+class Attractor : public Art {
+public:
+    Attractor()
+        : Art("strange attractors") {
+			//use_pixel_buffer = true;
+			pixel_buffer_maximum = 1024*1024;
+		}
+
+private:
+    virtual bool render_gui() override;
+    virtual void resize(int _w, int _h) override;
+    virtual bool render(uint32_t *p) override;
+
+    void init();
+    void draw();
+
+	int kcount = 16, count = 0;
+    PaletteSetting pal;
+
+    double a = 1, b = 2, c = 3, d = 4;
+    double ai, aj;
+    double inc = 1;
+
+};