A camera defines the region of the physics world that will be rendered on the canvas. More...
Typedefs | |
| typedef struct _EPhysics_Camera | EPhysics_Camera |
| Camera handle, used to change the position of the frame to be rendered. More... | |
A camera defines the region of the physics world that will be rendered on the canvas.
It sets the point of view.
Every world has a camera, that can be gotten with ephysics_world_camera_get(). Its position can be set with ephysics_camera_position_set() or can be set to track a body, with ephysics_camera_body_track();
| typedef struct _EPhysics_Camera EPhysics_Camera |
Camera handle, used to change the position of the frame to be rendered.
Every world have a camera that can be gotten with ephysics_world_camera_get().
| EAPI void ephysics_camera_position_set | ( | EPhysics_Camera * | camera, |
| Evas_Coord | x, | ||
| Evas_Coord | y | ||
| ) |
Set camera's position.
Camera's position referes to the position of the top-left point of the camera.
By default a camera is created to map the first quadrant of physics world from the point (0, 0) to (render area width / world rate, render area height / world rate).
When render area is set with ephysics_world_render_geometry_set(), the camera geometry is updated to match it. So, for most cases, camera won't need to be handled by the user.
But it can be modified passing another top-left point position, so another region of the physics world will be rendered on the render area. So if you have a scene larger than the render area, camera handling can be very useful.
This function will make camera stop tracking a body set with ephysics_camera_body_track().
| camera | The camera to be positioned. |
| x | The new position on x axis, in pixels. |
| y | The new position on y axis, in pixels. |
| EAPI void ephysics_camera_position_get | ( | const EPhysics_Camera * | camera, |
| Evas_Coord * | x, | ||
| Evas_Coord * | y | ||
| ) |
Get camera's position.
| camera | The world's camera. |
| x | Position on x axis, in pixels. |
| y | Position on y axis, in pixels. |
| EAPI void ephysics_camera_body_track | ( | EPhysics_Camera * | camera, |
| EPhysics_Body * | body, | ||
| Eina_Bool | horizontal, | ||
| Eina_Bool | vertical | ||
| ) |
Set camera to track a body.
When a body is tracked, the camera will move automatically, following this body. It will keeps the body centralized on rendered area. If it will be centralized horizontally and / or vertically depends if parameters horizontal and vertical are set to EINA_TRUE.
Default updates (ephysics_body_evas_object_update()) will take care of updating evas objects associated to the bodies correctly. But if you need to do it yourself, you'll need to take camera's position in consideration, using ephysics_camera_position_get().
| camera | The world's camera. |
| body | The body tracked by the camera, or NULL if camera isn't tracking any body. |
| horizontal | EINA_TRUE if body is tracked on x axis, EINA_FALSE otherwise; |
| vertical | EINA_TRUE if body is tracked on y axis, EINA_FALSE otherwise; |
| EAPI void ephysics_camera_tracked_body_get | ( | EPhysics_Camera * | camera, |
| EPhysics_Body ** | body, | ||
| Eina_Bool * | horizontal, | ||
| Eina_Bool * | vertical | ||
| ) |
Get body tracked by camera.
| camera | The world's camera. |
| body | The body tracked by the camera, or NULL if camera isn't tracking any body. |
| horizontal | EINA_TRUE if body is tracked on x axis, EINA_FALSE otherwise; |
| vertical | EINA_TRUE if body is tracked on y axis, EINA_FALSE otherwise; |
| EAPI void ephysics_camera_perspective_set | ( | EPhysics_Camera * | camera, |
| Evas_Coord | px, | ||
| Evas_Coord | py, | ||
| Evas_Coord | z0, | ||
| Evas_Coord | foc | ||
| ) |
Set perspective to be applied on the scene.
This applies a given perspective (3D) to the world rendering. It will be used when the scene is rendered, after each simulation step, by ephysics_body_evas_object_update().
The px and py points specify the "infinite distance" point in the 3D conversion (where all lines converge to like when artists draw 3D by hand). The z0 value specifies the z value at which there is a 1:1 mapping between spatial coordinates and screen coordinates. Any points on this z value will not have their X and Y values modified in the transform. Those further away (Z value higher) will shrink into the distance, and those less than this value will expand and become bigger. The foc value determines the "focal length" of the camera. This is in reality the distance between the camera lens plane itself (at or closer than this rendering results are undefined) and the z0 z value. This allows for some "depth" control and foc must be greater than 0.
Considering the world geometry, by default, perspective is set to px = x + w / 2, py = y + h / 2, z0 = z + d / 2 and foc = 10 * (z + d). This means the conversion point is centered on render area, and z0 is on the center of render area z axis. It is set when ephysics_world_render_geometry_set() is called.
| camera | The world's camera. |
| px | The perspective distance X coordinate |
| py | The perspective distance Y coordinate |
| z0 | The "0" z plane value |
| foc | The focal distance |
| EAPI void ephysics_camera_perspective_get | ( | const EPhysics_Camera * | camera, |
| Evas_Coord * | px, | ||
| Evas_Coord * | py, | ||
| Evas_Coord * | z0, | ||
| Evas_Coord * | foc | ||
| ) |
Get perspective applied on the scene.
| camera | The world's camera. |
| px | The perspective distance X coordinate |
| py | The perspective distance Y coordinate |
| z0 | The "0" z plane value |
| foc | The focal distance |
| EAPI void ephysics_camera_perspective_enabled_set | ( | EPhysics_Camera * | camera, |
| Eina_Bool | enabled | ||
| ) |
Set if perspective should be applied.
The applied perspective can be set with ephysics_camera_perspective_set().
| camera | The world's camera. |
| enabled | EINA_TRUE if perspective should be used, or EINA_FALSE if it shouldn't. |
| EAPI Eina_Bool ephysics_camera_perspective_enabled_get | ( | const EPhysics_Camera * | camera | ) |
Return if perspective is enabled or not.
| camera | The world's camera. |
EINA_TRUE if perspective is enabled, or EINA_FALSE if it isn't, or on error.