Make the cursor movable left and right

main.c

@@ -78,6 +78,7 @@ Font font_load_from_file(SDL_Renderer *renderer, const char *file_path)
     Font font = {0};
 
     SDL_Surface *font_surface = surface_from_file(file_path);
+    scc(SDL_SetColorKey(font_surface, SDL_TRUE, 0xFF000000));
     font.spritesheet = scp(SDL_CreateTextureFromSurface(renderer, font_surface));
     SDL_FreeSurface(font_surface);
 
@@ -96,7 +97,7 @@ Font font_load_from_file(SDL_Renderer *renderer, const char *file_path)
     return font;
 }
 
-void render_char(SDL_Renderer *renderer, Font *font, char c, Vec2f pos, float scale)
+void render_char(SDL_Renderer *renderer, const Font *font, char c, Vec2f pos, float scale)
 {
     const SDL_Rect dst = {
         .x = (int) floorf(pos.x),
@@ -111,15 +112,20 @@ void render_char(SDL_Renderer *renderer, Font *font, char c, Vec2f pos, float sc
     scc(SDL_RenderCopy(renderer, font->spritesheet, &font->glyph_table[index], &dst));
 }
 
-void render_text_sized(SDL_Renderer *renderer, Font *font, const char *text, size_t text_size, Vec2f pos, Uint32 color, float scale)
+void set_texture_color(SDL_Texture *texture, Uint32 color)
 {
     scc(SDL_SetTextureColorMod(
-            font->spritesheet,
+            texture,
             (color >> (8 * 0)) & 0xff,
             (color >> (8 * 1)) & 0xff,
             (color >> (8 * 2)) & 0xff));
 
-    scc(SDL_SetTextureAlphaMod(font->spritesheet, (color >> (8 * 3)) & 0xff));
+    scc(SDL_SetTextureAlphaMod(texture, (color >> (8 * 3)) & 0xff));
+}
+
+void render_text_sized(SDL_Renderer *renderer, Font *font, const char *text, size_t text_size, Vec2f pos, Uint32 color, float scale)
+{
+    set_texture_color(font->spritesheet, color);
 
     Vec2f pen = pos;
     for (size_t i = 0; i < text_size; ++i) {
@@ -145,19 +151,31 @@ size_t buffer_size = 0;
     ((color) >> (8 * 2)) & 0xFF, \
     ((color) >> (8 * 3)) & 0xFF
 
-void render_cursor(SDL_Renderer *renderer, Uint32 color)
+void render_cursor(SDL_Renderer *renderer, const Font *font)
 {
+    const Vec2f pos = vec2f(buffer_cursor * FONT_CHAR_WIDTH * FONT_SCALE, 0.0f);
+
     const SDL_Rect rect = {
-        .x = (int) floorf(buffer_cursor * FONT_CHAR_WIDTH * FONT_SCALE),
-        .y = 0,
+        .x = (int) floorf(pos.x),
+        .y = (int) floorf(pos.y),
         .w = FONT_CHAR_WIDTH * FONT_SCALE,
         .h = FONT_CHAR_HEIGHT * FONT_SCALE,
     };
 
-    scc(SDL_SetRenderDrawColor(renderer, UNHEX(color)));
+    scc(SDL_SetRenderDrawColor(renderer, UNHEX(0xFFFFFFFF)));
     scc(SDL_RenderFillRect(renderer, &rect));
+
+    set_texture_color(font->spritesheet, 0xFF000000);
+    if (buffer_cursor < buffer_size) {
+        render_char(renderer, font, buffer[buffer_cursor], pos, FONT_SCALE);
+    }
 }
 
+// TODO: move the cursor around
+// TODO: Blinking cursor
+// TODO: Multiple lines
+// TODO: Save/Load file
+
 int main(void)
 {
     scc(SDL_Init(SDL_INIT_VIDEO));
@@ -191,6 +209,18 @@ int main(void)
                     }
                 }
                 break;
+
+                case SDLK_LEFT: {
+                    if (buffer_cursor > 0) {
+                        buffer_cursor -= 1;
+                    }
+                } break;
+
+                case SDLK_RIGHT: {
+                    if (buffer_cursor < buffer_size) {
+                        buffer_cursor += 1;
+                    }
+                } break;
                 }
             }
             break;
@@ -213,7 +243,7 @@ int main(void)
         scc(SDL_RenderClear(renderer));
 
         render_text_sized(renderer, &font, buffer, buffer_size, vec2f(0.0, 0.0), 0xFFFFFFFF, FONT_SCALE);
-        render_cursor(renderer, 0xFFFFFFFF);
+        render_cursor(renderer, &font);
 
         SDL_RenderPresent(renderer);
     }