From 8c61343677d2ed8f929372863016524707b8ab93 Mon Sep 17 00:00:00 2001
From: Uros Majstorovic <majstor@majstor.org>
Date: Tue, 23 Mar 2021 21:33:57 +0100
Subject: form scroll completed

---
 fw/fe310/eos/eve/eve_phy.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 fw/fe310/eos/eve/eve_phy.c

(limited to 'fw/fe310/eos/eve/eve_phy.c')

diff --git a/fw/fe310/eos/eve/eve_phy.c b/fw/fe310/eos/eve/eve_phy.c
new file mode 100644
index 0000000..1e255fe
--- /dev/null
+++ b/fw/fe310/eos/eve/eve_phy.c
@@ -0,0 +1,77 @@
+#include <stdlib.h>
+#include <math.h>
+
+#include "eve_platform.h"
+#include "eve_phy.h"
+
+/* Constant accelerator */
+void eve_phy_acc_init(EVEPhyAcc *param, int a) {
+    param->a = a;
+}
+
+void eve_phy_acc_start(EVEPhyAcc *param, int x0, int y0, int v0x, int v0y) {
+    double v0 = sqrt(v0x * v0x + v0y * v0y);
+
+    param->x0 = x0;
+    param->y0 = y0;
+    param->v0x = v0x;
+    param->v0y = v0y;
+    param->k = 2 * v0 / param->a * EVE_RTC_FREQ;
+}
+
+int eve_phy_acc_tick(EVEPhyAcc *param, int dt, int *x, int *y) {
+    int k = param->k;
+    int x0 = param->x0;
+    int y0 = param->y0;
+    int v0x = param->v0x;
+    int v0y = param->v0y;
+    int more = 1;
+
+    if ((k < 0) && (dt >= -k / 2)) {
+        dt = -k / 2;
+        more = 0;
+    }
+    if (x) *x = x0 + (v0x * dt + v0x * dt / k * dt) / (int)(EVE_RTC_FREQ);
+    if (y) *y = y0 + (v0y * dt + v0y * dt / k * dt) / (int)(EVE_RTC_FREQ);
+
+    return more;
+}
+
+/* Linear harmonic oscillator */
+void eve_phy_lho_init(EVEPhyLHO *param, int x, int y, uint32_t T, double d, uint32_t t_max) {
+    double f0 = 2 * M_PI / (T * EVE_RTC_FREQ / 1000);
+
+    if (d < 0) d = 0;
+    if (d > 1) d = 1;
+    param->x = x;
+    param->y = y;
+    param->f = f0 * sqrt(1 - d * d);
+    param->a = -d * f0;
+    param->t_max = t_max * EVE_RTC_FREQ / 1000;
+}
+
+int eve_phy_lho_start(EVEPhyLHO *param, int x0, int y0) {
+    param->x0 = x0;
+    param->y0 = y0;
+}
+
+int eve_phy_lho_tick(EVEPhyLHO *param, int dt, int *x, int *y) {
+    int ax = param->x0 - param->x;
+    int ay = param->y0 - param->y;
+    int more = 1;
+
+    if (param->t_max && (dt >= param->t_max)) {
+        dt = param->t_max;
+        more = 0;
+    }
+    if (param->a) {
+        double e = exp(param->a * dt);
+        ax = ax * e;
+        ay = ay * e;
+        if ((ax == 0) && (ay == 0)) more = 0;
+    }
+    if (x) *x = param->x + ax * cos(param->f * dt);
+    if (y) *y = param->y + ay * cos(param->f * dt);
+
+    return more;
+}
-- 
cgit v1.2.3