From b6e253c13a2b0ad86d15c7fce9311c5d0804b823 Mon Sep 17 00:00:00 2001
From: David Graham <dpgraham4401@gmail.com>
Date: Sun, 5 May 2024 00:04:30 -0400
Subject: [PATCH] simple velocity model function for generating quick velocity
 model with just a starting velocity and gradient

---
 src/velocity.c         | 12 ++++++++++++
 src/velocity.h         |  3 +++
 test/velocity_test.cpp | 30 ++++++++++++++++++++++++++++++
 3 files changed, 45 insertions(+)

diff --git a/src/velocity.c b/src/velocity.c
index c0e7f56..b90f83d 100644
--- a/src/velocity.c
+++ b/src/velocity.c
@@ -14,3 +14,15 @@ VelocityModel *allocate_velocity_model(const int rows, const int cols) {
 
   return model;
 }
+
+VelocityModel *simple_velocity_model(VelocityModel *model,
+                                     const double gradient,
+                                     const double startingVelocity) {
+
+  for (int i = 0; i < model->rows; i++) {
+    for (int j = 0; j < model->cols; j++) {
+      model->data[i][j] = startingVelocity + gradient * i;
+    }
+  };
+  return model;
+}
diff --git a/src/velocity.h b/src/velocity.h
index 007c8a4..5b56f6c 100644
--- a/src/velocity.h
+++ b/src/velocity.h
@@ -13,4 +13,7 @@ typedef struct {
 
 VelocityModel *allocate_velocity_model(int rows, int cols);
 
+VelocityModel *simple_velocity_model(VelocityModel *model, double gradient,
+                                     double startingVelocity);
+
 #endif // VELOCITY_H
diff --git a/test/velocity_test.cpp b/test/velocity_test.cpp
index 5fe9205..cffe957 100644
--- a/test/velocity_test.cpp
+++ b/test/velocity_test.cpp
@@ -25,3 +25,33 @@ TEST(VelocityModel, AllocateVelocityModel) {
     ASSERT_NE(model->data[i], nullptr);
   }
 }
+
+TEST(SimpleVelocityModel, ShouldApplyCorrectGradient) {
+  int rows = 5;
+  int cols = 10;
+  double gradient = 2.0;
+  double startingVelocity = 1.0;
+  VelocityModel *model = allocate_velocity_model(rows, cols);
+  model = simple_velocity_model(model, gradient, startingVelocity);
+  for (int i = 0; i < model->rows; i++) {
+    for (int j = 0; j < model->cols; j++) {
+      ASSERT_EQ(model->data[i][j], startingVelocity + gradient * i);
+    }
+  }
+  free(model);
+}
+
+TEST(SimpleVelocityModel, ShouldHandleZeroGradient) {
+  int rows = 5;
+  int cols = 10;
+  double gradient = 0.0;
+  double startingVelocity = 1.0;
+  VelocityModel *model = allocate_velocity_model(rows, cols);
+  model = simple_velocity_model(model, gradient, startingVelocity);
+  for (int i = 0; i < model->rows; i++) {
+    for (int j = 0; j < model->cols; j++) {
+      ASSERT_EQ(model->data[i][j], startingVelocity);
+    }
+  }
+  free(model);
+}
\ No newline at end of file