Add basic ui_list UI component

include/ui_list.h

@@ -0,0 +1,28 @@
+#ifndef UI_LIST_H
+#define UI_LIST_H
+
+#include "SDL_pixels.h"
+#include "SDL_render.h"
+#include "aliases/aliases.h"
+
+typedef struct {
+  union {
+    u32 colour;
+    SDL_Color rgba;
+  };
+} colour_t;
+
+typedef struct {
+  u64 item_w;
+  u64 item_h;
+  u64 selected;
+  u64 length;
+  SDL_Texture **textures;
+  SDL_Texture **selected_textures;
+} ui_list_t;
+
+u64 ui_list(const ui_list_t *list, u64 x, u64 y, u64 padding, i64 mouse_x,
+            i64 mouse_y, i64 clicked_x, i64 clicked_y, SDL_Renderer *renderer,
+            colour_t bg_colour, colour_t hover_colour);
+
+#endif // !UI_LIST_H

src/ui_list.c

@@ -0,0 +1,78 @@
+#include "ui_list.h"
+#include "SDL_rect.h"
+#include "SDL_render.h"
+#include "aliases/aliases.h"
+#include <stdbool.h>
+#include <stdio.h>
+
+bool aabb(SDL_Rect *rect, i64 x, i64 y) {
+  return x >= rect->x && y >= rect->y && x < rect->x + rect->w &&
+         y < rect->y + rect->h;
+}
+
+bool draw_element(SDL_Texture *texture, SDL_Texture *selected_texture,
+                  bool selected, u64 x, u64 y, u64 item_w, u64 item_h,
+                  u64 padding, i64 mouse_x, i64 mouse_y, i64 clicked_x,
+                  i64 clicked_y, SDL_Renderer *renderer, colour_t bg_colour,
+                  colour_t hover_colour) {
+  bool output = false;
+
+  SDL_Rect bg_dest = {.x = x - padding,
+                      .y = y - padding,
+                      .w = item_w + padding * 2,
+                      .h = item_h + padding * 2 + 1};
+
+  SDL_Rect texture_dest = {.x = x, .y = y, .w = 0, .h = 0};
+
+  colour_t c = bg_colour;
+  bool hovered = false;
+
+  if (aabb(&bg_dest, mouse_x, mouse_y)) {
+    hovered = true;
+    c = hover_colour;
+  }
+
+  if (aabb(&bg_dest, clicked_x, clicked_y)) {
+    output = true;
+  }
+
+  SDL_SetRenderDrawColor(renderer, c.rgba.r, c.rgba.g, c.rgba.b, c.rgba.a);
+
+  SDL_Texture *render_texture =
+      (selected || hovered) ? selected_texture : texture;
+
+  i32 texture_w;
+  i32 texture_h;
+
+  SDL_QueryTexture(render_texture, NULL, NULL, &texture_w, &texture_h);
+
+  i32 x_offset = (item_w - texture_w) / 2;
+  texture_dest.x += x_offset;
+  texture_dest.w = texture_w;
+  texture_dest.h = texture_h;
+
+  (selected || hovered) ? SDL_RenderFillRect(renderer, &bg_dest)
+                        : SDL_RenderDrawRect(renderer, &bg_dest);
+
+  SDL_RenderCopy(renderer, render_texture, NULL, &texture_dest);
+
+  return output;
+}
+
+u64 ui_list(const ui_list_t *list, u64 x, u64 y, u64 padding, i64 mouse_x,
+            i64 mouse_y, i64 clicked_x, i64 clicked_y, SDL_Renderer *renderer,
+            colour_t bg_colour, colour_t hover_colour) {
+  u64 selected = list->selected;
+
+  for (u64 i = 0; i < list->length; ++i) {
+    if (draw_element(list->textures[i], list->selected_textures[i],
+                     i == list->selected, x,
+                     y + (list->item_h + padding * 2) * i, list->item_w,
+                     list->item_h, padding, mouse_x, mouse_y, clicked_x,
+                     clicked_y, renderer, bg_colour, hover_colour)) {
+      selected = i;
+    }
+  }
+
+  return selected;
+}