Math improvements and basic plotting

1 files changed, 86 insertions, 0 deletions

diff --git a/libs/libgui/widgets.c b/libs/libgui/widgets.c
index 1881655..b04f937 100644
--- a/libs/libgui/widgets.c
+++ b/libs/libgui/widgets.c
@@ -1,8 +1,10 @@
 // MIT License, Copyright (c) 2021 Marvin Borner
 
+#include <assert.h>
 #include <def.h>
 #include <libgui/gui.h>
 #include <libgui/widgets.h>
+#include <math.h>
 
 #define TEXT_PAD 2
 
@@ -26,3 +28,87 @@ void gui_button(u32 window, u32 widget, void (*click)(struct gui_event_mouse *ev
 {
 	gui_button_custom(window, widget, FONT_16, COLOR_WHITE, COLOR_BLACK, click, text);
 }
+
+/**
+ * Plot
+ */
+
+static void gui_plot_redraw(struct gui_plot *plot)
+{
+	if (plot->current <= 1)
+		return;
+
+	assert(plot->current <= plot->count);
+
+	gfx_fill(plot->ctx, COLOR_BG);
+
+	f64 min = 0.0, max = 0.0;
+	for (u32 i = 0; i < plot->current; i++) {
+		f64 current = plot->data[i];
+		if (current < min)
+			min = current;
+		if (current > max)
+			max = current;
+	}
+
+	vec2 size = vec2_sub(plot->ctx->size, vec2(2, 2)); // Margin
+	u32 diff = ABS(max - min);
+	u32 step = size.x / (plot->current - 1);
+	f64 scale = (f64)size.y / (diff + 1);
+
+	for (u32 i = 1; i < plot->current; i++) {
+		vec2 prev = vec2((i - 1) * step + 2, (max - plot->data[i - 1]) * scale);
+		vec2 current = vec2(i * step + 2, (max - plot->data[i]) * scale);
+		gfx_draw_line(plot->ctx, prev, current, 1, COLOR_RED);
+	}
+}
+
+void gui_plot_iterate(struct gui_plot *plot)
+{
+	plot->current++;
+	assert(plot->current <= plot->count);
+	gui_plot_redraw(plot);
+}
+
+void gui_plot_destroy(struct gui_plot *plot)
+{
+	free(plot->data);
+	free(plot);
+}
+
+void gui_plot_draw(struct gui_plot *plot)
+{
+	plot->current = plot->count;
+	gui_plot_redraw(plot);
+}
+
+struct gui_plot *gui_plot_data(u32 window, u32 widget, const f64 *data, u32 count)
+{
+	f64 *buffer = malloc(count * sizeof(*data));
+	memcpy(buffer, data, count * sizeof(*data));
+
+	struct gui_plot *plot = malloc(sizeof(*plot));
+	plot->data = buffer;
+	plot->current = 0;
+	plot->count = count;
+	plot->ctx = gui_widget_context(window, widget, GUI_LAYER_FG);
+	gui_fill(window, widget, GUI_LAYER_BG, COLOR_BG);
+	return plot;
+}
+
+struct gui_plot *gui_plot_cubic(u32 window, u32 widget, f64 delta, s32 x_min, s32 x_max, f64 a,
+				f64 b, f64 c, f64 d)
+{
+	assert(x_min < x_max);
+	u32 diff = FABS(x_max - x_min);
+	u32 count = mceil(diff * (1 / delta)) + 1;
+	f64 *data = zalloc(count * sizeof(*data));
+
+	for (u32 i = 0; i < count; i++)
+		data[i] = mcubic(x_min + i * delta, a, b, c, d);
+
+	struct gui_plot *plot = gui_plot_data(window, widget, data, count);
+
+	free(data);
+	return plot;
+}