added edge action argument

api-doc.txt

@@ -1,8 +1,21 @@
 The server listens on '/' for GET queries with a url query format like
 ?l=*&r0=*&g0=*&b0=*&a0=*&t0=* ... &rl=*&gl=*&bl=*&al=*&tl=*
+
 Where l is the number of points on a gradient. And each point of the gradient has a r* g* b* a* and t* where * is the index.
+
 r g and b are the red green and blue 8-bit colour components of a point on the gradient. A is the 5-bit global component of the led at that point.
 t is the offset from the start measured in leds.
+
 Each point also has an optional &m 'movement' argument. &m should be either -1, +1 or 0 and represents the movement per frame or the point.
-A point on the gradient can have an &m parameter, and has to have a &r, &g, &b, &a, and &t.
-The whole gradient can have a duration &d parameter and must have a length &l
+When no movement is set, 0 (no movement) is implied.
+
+When movement is set, a &e 'edge' component can also be set for that point. &e defines what the point will do once it reaches an end of the strip.
+Edge should be one of
+w to wrap to the opposite end of the strip.
+r to reverse direction
+s to stop
+
+If no &e is specified, s is implied.
+
+A point on the gradient may have a movement &m and edge &e parameter, and has to have a &r, &g, &b, &a, and &t.
+The whole gradient may have a duration &d parameter and must have a length &l

main/leds.c

@@ -156,23 +156,49 @@ void memswap(void* d, void* s, size_t n) {
     free(tmp);
 }
 
+static
+void led_check_edge(GradientPoint* point) {
+    int offset = clamp(point->offset, 0, 120);
+    switch(point->edge_action) {
+        default:
+        case LEDS_EDGE_WRAP:
+            if(point->offset < 0) {
+                point->offset += 120;
+            } else if(point->offset >= 120) {
+                point->offset %= 120;
+            }
+        break;
+        case LEDS_EDGE_REVERSE: {
+            if(offset != point->offset) {
+                point->offset = offset;
+                point->movement *= -1;
+            }
+            break;
+        }
+        case LEDS_EDGE_STOP:
+            point->offset = clamp(point->offset, 0, 120);
+        break;
+    }
+}
+
 void leds_animate() {
     for(size_t i = 0; i < g_current_gradient.points_len; ++i) {
         // The gradient point at i
         GradientPoint* point = g_current_gradient.points + i;
         // move towards end
         if(point->movement > 0) {
+            ++point->offset;
             // without moving past it
-            point->offset = min(point->offset + 1, 120);
-
+            led_check_edge(point);
             // swap with next point if we pass it
             if(point->offset > (point+1)->offset) {
                 memswap(point, point+1, sizeof(GradientPoint));
             }
         // move towards start
         } else if(point->movement < 0) {
+            ++point->offset;
             // without passing it
-            point->offset = max(0, point->offset - 1);
+            led_check_edge(point);
 
             // swap with previous point if we fall below it
             if(point->offset < (point-1)->offset) {

main/leds.h

@@ -18,6 +18,12 @@ typedef enum LedsSendStatus {
     LEDS_SENDING,
 } LedsSendStatus;
 
+typedef enum MoveEdgeAction {
+    LEDS_EDGE_WRAP,
+    LEDS_EDGE_REVERSE,
+    LEDS_EDGE_STOP
+} MoveEdgeAction;
+
 // pack the struct to match exactly 8 * 4 = 32bits
 typedef struct __attribute__((__packed__)) LedComponents {
     // RGB component values
@@ -37,8 +43,9 @@ typedef union Led {
 // point on a gradient
 typedef struct GradientPoint {
     union Led led;    // value of the led at this point
-    size_t offset;      // offset (measured in leds) from the beginning
+    int offset;      // offset (measured in leds) from the beginning
     short movement;     // direction of movement over time
+    MoveEdgeAction edge_action; // what to do when movement hits an end of the strip
 } GradientPoint;
 
 typedef struct Gradient {

main/parse.c

@@ -3,6 +3,16 @@
 #include <string.h>
 #include <esp_http_server.h>
 
+MoveEdgeAction strtoea(const char* str) {
+    if(strcmp(str, "w")) {
+        return LEDS_EDGE_WRAP;
+    } else if(strcmp(str, "r")) {
+        return LEDS_EDGE_REVERSE;
+    } else {
+        return LEDS_EDGE_STOP;
+    }
+}
+
 // parse a URL query as described in api-doc.txt into a valid Gradient struct.
 // If the gradient is invalid, the is_ok flag on the return value will be set, and error will be set to a message describing the problem.
 Result parse_leds_query(char* query_string, size_t query_size) {
@@ -75,11 +85,17 @@ Result parse_leds_query(char* query_string, size_t query_size) {
         // Get the movement variable &m.
         // Interpreted as an integer number from -1 to +1
         sprintf(query_key, "m%d", point);
-        if(gradient->duration > 0 && httpd_query_key_value(query_string, query_key, query_value, sizeof(query_value)) == ESP_OK) {
+        if(httpd_query_key_value(query_string, query_key, query_value, sizeof(query_value)) == ESP_OK) {
             gradient->points[point].movement = clamp(-1, +1, atoi(query_value));
         } else {
             gradient->points[point].movement = 0;
         }
+        sprintf(query_key, "e%d", point);
+        if(httpd_query_key_value(query_string, query_key, query_value, sizeof(query_value)) == ESP_OK) {
+            gradient->points[point].edge_action = strtoea(query_value);
+        } else {
+            gradient->points[point].edge_action = LEDS_EDGE_STOP;
+        }
 
         // Log fetched fields
         LOGLN("led[%d]:", point);