refactor camera and a few miscellaneous thingsHEADmaster

1 files changed, 37 insertions, 0 deletions

diff --git a/src/camera.c b/src/camera.c
new file mode 100644
index 0000000..68376b8
--- /dev/null
+++ b/src/camera.c
@@ -0,0 +1,37 @@
+#include "camera.h"
+
+struct camera
+camera_init(const int image_width, const int image_height,
+            const float focal_length)
+{
+	struct camera cam;
+	float viewport_height, viewport_width;
+
+	cam.centre.s[0] = 0.0f;
+	cam.centre.s[1] = 0.0f;
+	cam.centre.s[2] = 0.0f;
+
+	viewport_height = 2.0f;
+	viewport_width =
+	        viewport_height * ((float)image_width / (float)image_height);
+
+	cam.pixel_delta_u.s[0] = viewport_width / (float)image_width;
+	cam.pixel_delta_u.s[1] = 0.0f;
+	cam.pixel_delta_u.s[2] = 0.0f;
+
+	cam.pixel_delta_v.s[0] = 0.0f;
+	cam.pixel_delta_v.s[1] = -viewport_height / (float)image_height;
+	cam.pixel_delta_v.s[2] = 0.0f;
+
+	cam.corner00.s[0] =
+	        cam.centre.s[0] - viewport_width / 2.0f +
+	        0.5f * (cam.pixel_delta_u.s[0] + cam.pixel_delta_v.s[0]);
+	cam.corner00.s[1] =
+	        cam.centre.s[1] + viewport_height / 2.0f +
+	        0.5f * (cam.pixel_delta_u.s[1] + cam.pixel_delta_v.s[1]);
+	cam.corner00.s[2] =
+	        cam.centre.s[2] - focal_length +
+	        0.5f * (cam.pixel_delta_u.s[2] + cam.pixel_delta_v.s[2]);
+
+	return cam;
+}