Successfull sum function in wasm :D

client/index.js

@@ -286,4 +286,7 @@ function main() {
     schedule_draw(state, context);
 
     state.timers.offline_toast = setTimeout(() => ui_offline(), config.initial_offline_timeout);
+
+
+    test_wasm();
 }

client/speed.js

@@ -1,3 +1,20 @@
+async function test_wasm() {
+    const memory = new WebAssembly.Memory({ initial: 10, maximum: 100 });
+    const results = await WebAssembly.instantiateStreaming(fetch('wasm/lod.wasm'));
+    const numbers_offset = results.instance.exports.alloc(40);
+
+    const numbers = new Uint32Array(results.instance.exports.memory.buffer, numbers_offset, 10);
+
+    for (let i = 0; i < 10; ++i) {
+        numbers[i] = i;
+    }
+
+    console.log(numbers);
+
+    const sum = results.instance.exports.sum(numbers_offset, 10);
+    console.log(sum);
+}
+
 function rdp_find_max(state, zoom, coords_from, start, end) {
     // Finds a point from the range [start, end) with the maximum distance from the line (start--end) that is also further than EPS
     const EPS = 1.0 / zoom;

client/wasm/lod.c

@@ -1,6 +1,27 @@
-float sqrtf(float x);
-float fabsf(float x);
+extern char __heap_base;
+static int allocated;
 
+void *
+alloc(int size)
+{
+    void *result = &__heap_base + allocated;
+    allocated += size;
+    return(result);
+}
+
+int
+sum(int *numbers, int count)
+{
+    int result = 0;
+    
+    for (int i = 0; i < count; ++i) {
+        result += numbers[i];
+    }
+    
+    return(result);
+}
+
+#if 0
 static int
 rdp_find_max(float *coordinates, float zoom, int coords_from, 
              int segment_start, int segment_end)
@@ -12,13 +33,13 @@ rdp_find_max(float *coordinates, float zoom, int coords_from,
     
     float ax = coordinates[coords_from + segment_start * 2 + 0];
     float ay = coordinates[coords_from + segment_start * 2 + 1];
-    float bx = coordinates[coords_from + segment_end * 2 + 0];
-    float by = coordinates[coords_from + segment_end * 2 + 1];
+    float bx = coordinates[coords_from   + segment_end * 2 + 0];
+    float by = coordinates[coords_from   + segment_end * 2 + 1];
     
     float dx = bx - ax;
     float dy = by - ay;
     
-    float dist_ab = sqrtf(dx * dx + dy * dy);
+    float dist_ab = __builtin_sqrtf(dx * dx + dy * dy);
     float dir_nx = dy / dist_ab;
     float dir_ny = -dx / dist_ab;
     
@@ -29,7 +50,7 @@ rdp_find_max(float *coordinates, float zoom, int coords_from,
         float apx = px - ax;
         float apy = py - ay;
         
-        float dist = fabsf(apx * dir_nx + apy * dir_ny);
+        float dist = __builtin_fabsf(apx * dir_nx + apy * dir_ny);
         
         if (dist > EPS && dist > max_dist) {
             result = i;
@@ -112,4 +133,5 @@ do_lod(int *clipped_indices, int clipped_count, float zoom,
     }
     
     return(segments_head);
-}
+}
+#endif