twn_draw.h: new camera api

include/twn_camera.h

@@ -1,22 +0,0 @@
-#ifndef TWN_CAMERA_H
-#define TWN_CAMERA_H
-
-#include "twn_types.h"
-#include "twn_engine_api.h"
-
-/* TODO: make it cached? */
-/*       for example, perspective matrix only needs recaluclation on FOV change */
-
-/* first person camera class */
-typedef struct Camera {
-    Vec3 pos;        /* eye position */
-    Vec3 target;     /* normalized target vector */
-    Vec3 up;         /* normalized up vector */
-    float fov;          /* field of view, in radians */
-} Camera;
-
-TWN_API Matrix4 camera_look_at(const Camera *camera);
-
-TWN_API Matrix4 camera_perspective(const Camera *const camera);
-
-#endif

include/twn_draw.h

@@ -3,7 +3,6 @@
 
 #include "twn_types.h"
 #include "twn_option.h"
-#include "twn_camera.h"
 #include "twn_engine_api.h"
 
 #include <stdbool.h>
@@ -76,8 +75,21 @@ TWN_API void draw_triangle(char const *path,
 //                       Vec2 scaling,
 //                       Rect uvs);
 
-/* pushes a camera state to be used for all future unfurl_* commands */
-TWN_API void draw_camera(const Camera *camera);
+/* sets a perspective 3d camera to be used for all 3d commands */
+TWN_API void draw_camera(Vec3 position, float fov, Vec3 up, Vec3 direction);
+
+/* same as draw_camera(), but with specific use case */
+/* direction and up vectors are inferred from roll, pitch and yaw parameters (in radians) */
+/* return value is direction and up vectors, so that you can use them in logic (such as controllers) */
+typedef struct DrawCameraFromPrincipalAxesResult {
+    Vec3 direction;
+    Vec3 up;
+} DrawCameraFromPrincipalAxesResult;
+DrawCameraFromPrincipalAxesResult TWN_API draw_camera_from_principal_axes(Vec3 position,
+                                                                          float fov,
+                                                                          float roll,
+                                                                          float pitch,
+                                                                          float yaw);
 
 /* expects '*' masks that will be expanded to 6 names: 'up', 'down', 'east', 'west', 'north' and 'south' */
 TWN_API void draw_skybox(const char *paths);