simple velocity model function for generating quick velocity model wi…

…th just a starting velocity and gradient

.gitignore

@@ -26,6 +26,7 @@
 **/*.cbp
 **/CMakeScripts
 **/compile_commands.json
+**/_deps
 
 ## Local
 .idea/

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;
+}

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

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);
+}