diff options
Diffstat (limited to 'src/render_sprite.c')
| -rw-r--r-- | src/render_sprite.c | 94 |
1 files changed, 64 insertions, 30 deletions
diff --git a/src/render_sprite.c b/src/render_sprite.c index 379f67a..2ca34c0 100644 --- a/src/render_sprite.c +++ b/src/render_sprite.c @@ -6,47 +6,80 @@ /* By: cacharle <marvin@42.fr> +#+ +:+ +#+ */ /* +#+#+#+#+#+ +#+ */ /* Created: 2020/02/02 17:39:07 by cacharle #+# #+# */ -/* Updated: 2020/02/04 03:38:53 by cacharle ### ########.fr */ +/* Updated: 2020/02/04 23:25:21 by cacharle ### ########.fr */ /* */ /* ************************************************************************** */ #include "cub3d.h" +/* +** 1: While raycasting the walls, store the perpendicular distance +** of each vertical stripe in a 1D ZBuffer +** 2: Calculate the distance of each sprite to the player +** 3: Use this distance to sort the sprites, from furthest away +** to closest to the camera +** 4: Project the sprite on the camera plane (in 2D): +** subtract the player position from the sprite position, +** then multiply the result with the inverse of the 2x2 camera matrix +** 5: Calculate the size of the sprite on the screen +** (both in x and y direction) by using the perpendicular distance +** 6: Draw the sprites vertical stripe by vertical stripe, +** don't draw the vertical stripe if the distance is further away +** than the 1D ZBuffer of the walls of the current stripe +** 7: Draw the vertical stripe pixel by pixel, make sure there's +** an invisible color or all sprites would be rectangles +*/ + +static void draw_stripe_pixels(t_state *state, t_sprite_state *sstate, + int stripe, int tex_x) +{ + int y; + int d; + int tex_y; + t_color color; + + y = sstate->draw_start - 1; + while (++y < sstate->draw_end_y) + { + d = y * 256 - state->window.height * 128 + sstate->sprite_height * 128; + tex_y = (d * state->textures[TEX_SPRITE].height) + / (sstate->sprite_height * 256); + color = ((t_color*)state->textures[TEX_SPRITE].data) + [state->textures[TEX_SPRITE].width * tex_y + tex_x]; + if ((color.hexcode & 0x00FFFFFF) != 0) + ((t_color*)state->window.data)[y * state->window.width + stripe] = + color; + } +} + static void draw_stripe(t_state *state, t_sprite_state *sstate, int stripe) { int tex_width; int tex_height; int tex_x; - int y; tex_width = state->textures[TEX_SPRITE].width; tex_height = state->textures[TEX_SPRITE].height; - tex_x = (int)(256 * (stripe - (-sstate->sprite_width / 2 + sstate->sprite_window_x)) - * tex_width / sstate->sprite_width) / 256; - if (!(sstate->transform.y > 0 && stripe > 0 && stripe < state->window.width && sstate->transform.y < state->z_buffer[stripe])) + tex_x = (int)(256 * (stripe - (-sstate->sprite_width / 2 + + sstate->sprite_window_x)) + * tex_width / sstate->sprite_width) / 256; + if (!(sstate->transform.y > 0 && stripe > 0 && stripe < state->window.width + && sstate->transform.y < state->z_buffer[stripe])) return ; - y = sstate->draw_start - 1; - while (++y < sstate->draw_end_y) - { - int d = y * 256 - state->window.height * 128 + sstate->sprite_height * 128; - int tex_y = ((d * tex_height) / sstate->sprite_height) / 256; - t_color color = ((t_color*)state->textures[TEX_SPRITE].data)[tex_width * tex_y + tex_x]; - if ((color.hexcode & 0x00FFFFFF) != 0) - ((t_color*)state->window.data)[y * state->window.width + stripe] = color; - } + draw_stripe_pixels(state, sstate, stripe, tex_x); } -static void sprite_boundary(t_state *state, t_sprite_state *sstate) +static void sprite_boundary(t_state *state, t_sprite_state *sstate) { sstate->sprite_height = ft_abs((int)(state->window.height / (sstate->transform.y))); sstate->draw_start = -sstate->sprite_height / 2 + state->window.height / 2; - if(sstate->draw_start < 0) + if (sstate->draw_start < 0) sstate->draw_start = 0; sstate->draw_end_y = sstate->sprite_height / 2 + state->window.height / 2; - if(sstate->draw_end_y >= state->window.height) + if (sstate->draw_end_y >= state->window.height) sstate->draw_end_y = state->window.height - 1; - sstate->sprite_width = ft_abs( (int) (state->window.height + sstate->sprite_width = ft_abs((int)(state->window.height / (sstate->transform.y))); sstate->draw_start_x = -sstate->sprite_width / 2 + sstate->sprite_window_x; if (sstate->draw_start_x < 0) @@ -56,28 +89,29 @@ static void sprite_boundary(t_state *state, t_sprite_state *sstate) sstate->draw_end_x = state->window.width - 1; } -static void render_sprite(t_state *state, int i) +static void render_sprite(t_state *state, int i) { int stripe; t_sprite_state sstate; + double inverse_det; + t_vector sprite; - sstate.sprite.x = state->sprites[i].pos.x - state->pos.x; - sstate.sprite.y = state->sprites[i].pos.y - state->pos.y; - sstate.inverse_det = 1.0 / (state->plane.x - * state->dir.y - state->dir.x * state->plane.y); - sstate.transform.x = sstate.inverse_det - * (state->dir.y * sstate.sprite.x - state->dir.x * sstate.sprite.y); - sstate.transform.y = sstate.inverse_det * (-state->plane.y - * sstate.sprite.x + state->plane.x * sstate.sprite.y); - sstate.sprite_window_x = (int)((state->window.width / 2) - * (1 + sstate.transform.x / sstate.transform.y)); + sprite = vector_add(state->sprites[i].pos, vector_scale(state->pos, -1.0)); + inverse_det = 1.0 / (state->plane.x * state->dir.y + - state->dir.x * state->plane.y); + sstate.transform.x = state->dir.y * sprite.x - state->dir.x * sprite.y; + sstate.transform.y = + -state->plane.y * sprite.x + state->plane.x * sprite.y; + sstate.transform = vector_scale(sstate.transform, inverse_det); + sstate.sprite_window_x = (int)((state->window.width / 2.0) + * (1.0 + sstate.transform.x / sstate.transform.y)); sprite_boundary(state, &sstate); stripe = sstate.draw_start_x - 1; while (++stripe < sstate.draw_end_x) draw_stripe(state, &sstate, stripe); } -void render_update_sprite(t_state *state) +void render_update_sprite(t_state *state) { int i; 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