diff options
| -rw-r--r-- | src/sars.c | 40 | ||||
| -rw-r--r-- | src/sars.h | 3 |
2 files changed, 43 insertions, 0 deletions
@@ -110,6 +110,44 @@ void sars_viewport_from_ndc(sars_t *sars, float x, float y, int *res_x, int *res } +void sars_ndc_to_bpc(sars_t *sars, float x, float y, float *res_x, float *res_y) +{ + v3f_t coord = { .x = x, .y = y}, res; + + res = m4f_mult_v3f(&sars->projection_x_inv, &coord); + + /* it's not particularly useful to return coordinates outside the projection, + * rather than having everything using this function have to clamp or otherwise + * handle the result within these bounds, just do it here. Callers wanting to + * work with coordinates outside the projection arguably shouldn't be going through + * this transformation in the first place; they're clearly interested + * in viewport/screen-space or canvas-space coordinates, not projection coordinates. + */ + + if (res.x > 1.f) + res.x = 1.f; + else if (res.x < -1.f) + res.x = -1.f; + + if (res.y > 1.f) + res.y = 1.f; + else if (res.y < -1.f) + res.y = -1.f; + + *res_x = res.x; + *res_y = res.y; +} + + +void sars_viewport_to_bpc(sars_t *sars, int x, int y, float *res_x, float *res_y) +{ + v3f_t coord = {}; + + sars_viewport_to_ndc(sars, x, y, &coord.x, &coord.y); + sars_ndc_to_bpc(sars, coord.x, coord.y, res_x, res_y); +} + + uint32_t sars_viewport_id(sars_t *sars) { return SDL_GetWindowID(sars->window); @@ -149,6 +187,8 @@ static void sars_update_projection_x(sars_t *sars) sars->projection_x = m4f_identity(); else sars->projection_x = sars_boxed_projection_x(sars); + + sars->projection_x_inv = m4f_invert(&sars->projection_x); } @@ -45,6 +45,7 @@ typedef struct sars_t { sars_winmode_t winmode; m4f_t projection_x; + m4f_t projection_x_inv; } sars_t; void sars_canvas_size(sars_t *sars, int *res_width, int *res_height); @@ -53,6 +54,8 @@ void sars_canvas_from_ndc(sars_t *sars, float x, float y, int *res_x, int *res_y void sars_viewport_size(sars_t *sars, int *res_width, int *res_height); void sars_viewport_to_ndc(sars_t *sars, int x, int y, float *res_x, float *res_y); void sars_viewport_from_ndc(sars_t *sars, float x, float y, int *res_x, int *res_y); +void sars_ndc_to_bpc(sars_t *sars, float x, float y, float *res_x, float *res_y); +void sars_viewport_to_bpc(sars_t *sars, int x, int y, float *res_x, float *res_y); uint32_t sars_viewport_id(sars_t *sars); void sars_render(play_t *play, void *context); void sars_dispatch(play_t *play, void *context, SDL_Event *event); |