86 lines
2.3 KiB
C++
86 lines
2.3 KiB
C++
/* The world is a drop chute, arranged horizontally. The coordinate system is
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right-handed, with the following orientation from the top view of the chute:
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z
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^
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y (x)-----> x
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The player primarily moves in the +y direction (... although in practice
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objects move towards the player to better use the limited range of fixed-
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point values).
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We compute directions of rays based on points on the virtual screen placed
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in the world, in front of the camera. We make rays start at the camera
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position so the distance between the camera and screen does not matter; we
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arbitrarily place the screen at a distance which makes the screen height
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correspond to 2*HALF_SCREEN_HEIGHT world units. This is to help avoid
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precision loss with fixed-point numbers. */
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#include <num/num.h>
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#include <num/vec.h>
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using namespace libnum;
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struct mat3;
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/* Number of world units that we fix the screen's half height to. The screen is
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placed at the correct distance to make that happen. */
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#define HALF_SCREEN_HEIGHT 2
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/* World boundaries */
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#define WORLD_SIZE 8 /* (± 4) */
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/* Viewport size, in pixels */
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#define VWIDTH 198
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#define VHEIGHT 112
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struct camera {
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num fov;
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num screen_distance;
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/* Camera position (usually stays at z=0, objects move towards it) */
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vec3 pos;
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/* Angles of rotation */
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float yaw, pitch, roll;
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num cos_r, sin_r;
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num cos_p, sin_p;
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num cos_y, sin_y;
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/* Corresponding directions, in world coordinates */
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vec3 forward, right, up;
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/* Game stuff... */
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num neon_position;
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};
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void camera_set_fov(struct camera *camera, float fov_degrees);
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mat3 matrix_camera2world(struct camera const *camera);
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void camera_update_angles(struct camera *camera);
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void render_fragment(struct camera const *camera, uint16_t *fragment,
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int y_start, int y_height);
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//=== Azur shader wrapping the raytracing ===//
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void cd_raytrace(struct camera const *camera);
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void cd_raytrace_configure(void);
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//=== Input management ===//
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struct input {
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bool left;
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bool right;
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bool up;
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bool down;
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bool OPTN;
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};
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//=== Additions to libnum ===//
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struct mat3
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{
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num x11, x12, x13;
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num x21, x22, x23;
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num x31, x32, x33;
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};
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mat3 operator *(mat3 const &A, mat3 const &B);
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vec3 operator *(mat3 const &M, vec3 const &u);
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