From d1d7cfef7d2f1035e46b386579b20fdbd7240288 Mon Sep 17 00:00:00 2001
From: Randy McShandy <randy@mcshandy.xyz>
Date: Thu, 7 Dec 2023 23:11:12 -0600
Subject: [PATCH] Some simplifications and additions but still desperately
 needs more threads or somethings

---
 structs.h | 24 ++++++++++++++++++++++
 utils.c   | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 utils.h   |  8 ++++++++
 3 files changed, 92 insertions(+)
 create mode 100644 structs.h
 create mode 100644 utils.c
 create mode 100644 utils.h

diff --git a/structs.h b/structs.h
new file mode 100644
index 0000000..c10ed09
--- /dev/null
+++ b/structs.h
@@ -0,0 +1,24 @@
+#define GRID_X 256
+#define GRID_Y 256
+
+typedef struct
+{
+    float v[3][3];
+
+} Mat3;
+
+typedef struct
+{
+    float a;
+    float b;
+} FVec2;
+
+typedef struct
+{
+    float diff_a;
+    float diff_b;
+    float feed;
+    float kill;
+    float delta_t;
+} RD_Opts;
+
diff --git a/utils.c b/utils.c
new file mode 100644
index 0000000..b20db76
--- /dev/null
+++ b/utils.c
@@ -0,0 +1,60 @@
+#include "structs.h"
+
+FVec2 grid[GRID_X][GRID_Y];
+FVec2 grid_prime[GRID_X][GRID_Y];
+
+float convolve(Mat3 kernel, Mat3 source)
+{
+    float result = 0.0f;
+
+    // Convolve kernel at grid[x,y]
+    for (int ix = 0; ix < 3; ix++)
+    {
+        for (int iy = 0; iy < 3; iy++)
+        {
+            result += (kernel.v[ix][iy] * source.v[ix][iy]);
+        }
+    }
+
+    return result;
+}
+
+float rd_a_prime(RD_Opts opts, int x, int y, Mat3 kernel, float A, float B)
+{
+    float a_prime = 1.0f;
+    // Use species A in the convolution, b_prime will need B
+    // For now we won't iterate over edge rows and columns to avoid special case vomit
+    Mat3 source =
+    {
+        .v =
+        {
+            {grid[x-1][y-1].a,  grid[x][y-1].a, grid[x+1][y-1].a},
+            {grid[x-1][y+0].a,  grid[x][y+0].a, grid[x+1][y+0].a},
+            {grid[x-1][y+1].a,  grid[x][y+1].a, grid[x+1][y+1].a},
+        }
+    };
+
+    a_prime = A + (opts.diff_a*(convolve(kernel, source)) - (A*B*B) + opts.feed*(1.0f-A)) * opts.delta_t;
+
+    return a_prime;
+}
+
+float rd_b_prime(RD_Opts opts, int x, int y, Mat3 kernel, float A, float B)
+{
+    float b_prime = 1.0f;
+    // Use species A in the convolution, b_prime will need B
+    Mat3 source =
+    {
+        .v =
+        {
+            {grid[x-1][y-1].b,  grid[x][y-1].b, grid[x+1][y-1].b},
+            {grid[x-1][y+0].b,  grid[x][y+0].b, grid[x+1][y+0].b},
+            {grid[x-1][y+1].b,  grid[x][y+1].b, grid[x+1][y+1].b},
+        }
+    };
+
+    b_prime = B + (opts.diff_b*(convolve(kernel, source)) + A*(B*B) - (opts.kill + opts.feed)*B) * opts.delta_t;
+
+    return b_prime;
+}
+
diff --git a/utils.h b/utils.h
new file mode 100644
index 0000000..8121a81
--- /dev/null
+++ b/utils.h
@@ -0,0 +1,8 @@
+
+float convolve(Mat3 kernel, Mat3 source);
+float rd_a_prime(RD_Opts opts, int x, int y, Mat3 kernel, float A, float B);
+float rd_b_prime(RD_Opts opts, int x, int y, Mat3 kernel, float A, float B);
+
+extern FVec2 grid[GRID_X][GRID_Y];
+extern FVec2 grid_prime[GRID_X][GRID_Y];
+
-- 
2.49.0