From aa3906bf0bc9603511f1819e851748a93f80251e Mon Sep 17 00:00:00 2001
From: Marcus Penate <mpenate0@gmail.com>
Date: Wed, 20 Oct 2021 22:46:08 -0400
Subject: [PATCH] Added configuration constants to the gpu kernel

---
 gpu_kernel.clcpp | 48 ++++++++++++++++++++++++++++++------------------
 src/main.cpp     |  4 ++--
 2 files changed, 32 insertions(+), 20 deletions(-)

diff --git a/gpu_kernel.clcpp b/gpu_kernel.clcpp
index 75b9883..2900caa 100644
--- a/gpu_kernel.clcpp
+++ b/gpu_kernel.clcpp
@@ -10,6 +10,15 @@ static float *ground;
 static float *working_ground;
 static int2 ground_dimensions;
 
+constant float sense_distance = 3.0f;
+constant float move_distance = 3.0f;
+constant float diffusion_rate = 0.05f;
+constant float cone_of_vision = 2.0f*M_PI_F/4.0f;
+constant float vision_sensing_steps = 8.0f;
+constant float color_r = 0.0f;
+constant float color_g = 255.0f;
+constant float color_b = 255.0f;
+
 uint hash(uint input)
 {
     input ^= 2747636419u;
@@ -56,7 +65,7 @@ void kernel update_ground()
         }
     }
 
-    working_ground[current_index] = sum/9.0f-0.005f;
+    working_ground[current_index] = sum/9.0f-diffusion_rate;
 
     if (working_ground[current_index] < 0)
     {
@@ -78,27 +87,32 @@ void kernel move_agents()
     if (psuedorandom_int % 100 < 12)
     {
         psuedorandom_int = hash(psuedorandom_int);
-        agents[current_index].direction += (float)(psuedorandom_int%1000)*M_PI_F/3.0f/1000.0f-M_PI_F/6.0f;
+        agents[current_index].direction += (float)(psuedorandom_int%1000)*cone_of_vision/1000.0f-cone_of_vision/2.0f;
     }
     else
     {
-        float lsense = ground[(int)(agents[current_index].x+2.0f*cos(agents[current_index].direction+M_PI_F/6.0f)) + (int)(agents[current_index].y+2.0f*sin(agents[current_index].direction+M_PI_F/6.0f)) * ground_dimensions[0]];
-        float ssense = ground[(int)(agents[current_index].x+2.0f*cos(agents[current_index].direction)) + (int)(agents[current_index].y+2.0f*sin(agents[current_index].direction)) * ground_dimensions[0]];
-        float rsense = ground[(int)(agents[current_index].x+2.0f*cos(agents[current_index].direction-M_PI_F/6.0f)) + (int)(agents[current_index].y+2.0f*sin(agents[current_index].direction-M_PI_F/6.0f)) * ground_dimensions[0]];
+        float directional_change = cone_of_vision/2.0f;
+        float mx = agents[current_index].x + sense_distance*cos(agents[current_index].direction+directional_change);
+        float my = agents[current_index].y + sense_distance*sin(agents[current_index].direction+directional_change);
+        float max_sense = ground[(int)mx+(int)my*ground_dimensions[0]];
 
-        if (lsense > ssense && lsense > rsense)
+        for(int i = 1; i <= 8; i++)
         {
-            agents[current_index].direction += M_PI_F/6.0f;
+            mx = agents[current_index].x + sense_distance*cos(agents[current_index].direction+cone_of_vision/2.0f-(float)i*cone_of_vision/vision_sensing_steps);
+            my = agents[current_index].y + sense_distance*sin(agents[current_index].direction+cone_of_vision/2.0f-(float)i*cone_of_vision/vision_sensing_steps);
+
+            if (ground[(int)mx+(int)my*ground_dimensions[0]] > max_sense)
+            {
+                directional_change = cone_of_vision/2.0f-(float)i*cone_of_vision/vision_sensing_steps;
+                max_sense = ground[(int)mx+(int)my*ground_dimensions[0]];
+            }
         }
 
-        if (rsense > ssense && rsense > lsense)
-        {
-            agents[current_index].direction += -M_PI_F/6.0f;
-        }
+        agents[current_index].direction += directional_change;
     }
 
-    float nx = agents[current_index].x + cos(agents[current_index].direction);
-    float ny = agents[current_index].y + sin(agents[current_index].direction);
+    float nx = agents[current_index].x + move_distance*cos(agents[current_index].direction);
+    float ny = agents[current_index].y + move_distance*sin(agents[current_index].direction);
 
     if(nx < 0.0f || nx >= ground_dimensions[0] || ny < 0.0f || ny >= ground_dimensions[1])
     {
@@ -126,10 +140,8 @@ void kernel fill_draw_data(global uchar* draw_data)
 {
     int index = get_global_id(0);
 
-    uchar val = (uchar)(255.0f*ground[index]);
-
-    draw_data[4*index] = val;
-    draw_data[4*index+1] = val;
-    draw_data[4*index+2] = val;
+    draw_data[4*index] = (uchar)(color_b*ground[index]);
+    draw_data[4*index+1] = (uchar)(color_g*ground[index]);
+    draw_data[4*index+2] = (uchar)(color_r*ground[index]);
     draw_data[4*index+3] = 255;
 }
\ No newline at end of file
diff --git a/src/main.cpp b/src/main.cpp
index 81aad11..6907aaa 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -73,7 +73,7 @@ int main(int argc, char* argv[])
         SDL_LockTexture(start_texture, NULL, (void**)&u8_pixels,&i_pitch);
 
         int i_created = 0;
-        uint32_t u32_radius = 4*((u32_width<u32_height)?u32_width:u32_height)/10;
+        uint32_t u32_radius = 1*((u32_width<u32_height)?u32_width:u32_height)/10;
         while(i_created < i_agent_count)
         {
             float r = u32_radius*sqrt((float)rand()/(float)RAND_MAX);
@@ -215,7 +215,7 @@ int main(int argc, char* argv[])
     unsigned long long ull_time_old, ull_time_now;
     ull_time_now = ull_time_old = sys_time_us();
 
-    int iteration_duration = 16666;
+    int iteration_duration = 16666/10;
     bool pause = true;
 
     while(true)