cell selection and number input

cudoku.c

@@ -1,6 +1,7 @@
 #include <stdio.h>
 #include <stdbool.h>
 #include <stdlib.h>
+#include <math.h>
 
 #include <glad/gl.h>
 #include "3rdparty/stb/stb_image.h"
@@ -99,17 +100,20 @@ void draw_bg_grid_texture(Shader shader, unsigned int vao, unsigned int texture,
   glBindVertexArray(vao);
   glBindTexture(GL_TEXTURE_2D, texture);
   glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
+
+  glBindVertexArray(0);
 }
 
 void draw_numbers(Shader shader, unsigned int vao, unsigned int vbo, float *transform, int board[9][9]) {
-  // TODO: go thru the board state and call draw_text() with the appropriate number
-  // and position
-
   for (int i = 0; i < 9; i++) {
     for (int j = 0; j < 9; j++) {
-      draw_number(shader, board[i][j], i, j, 5.0f, vao, vbo, transform);
+      if (board[i][j] != 0) {
+        draw_number(shader, board[i][j], i, j, 5.0f, vao, vbo, transform);
+      }
     }
   }
+
+  glBindVertexArray(0);
 }
 
 void draw_win_overlay(Shader shader, unsigned int vao, unsigned int vbo, float *transform) {
@@ -117,3 +121,105 @@ void draw_win_overlay(Shader shader, unsigned int vao, unsigned int vbo, float *
   Size text_size = calculate_text_size(text, 1.0f);
   draw_text(shader, text, text_size, 1.5f, vao, vbo, transform);
 }
+
+void prepare_selection_box(unsigned int *vao, unsigned int *vbo) {
+  glGenVertexArrays(1, &(*vao));
+  glGenBuffers(1, &(*vbo));
+
+  glBindVertexArray(*vao);
+  glBindBuffer(GL_ARRAY_BUFFER, *vbo);
+
+  glBufferData(GL_ARRAY_BUFFER, sizeof(float) * 6*2, NULL, GL_DYNAMIC_DRAW);
+
+  glEnableVertexAttribArray(0);
+  glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), 0);
+
+  glBindBuffer(GL_ARRAY_BUFFER, 0);
+  glBindVertexArray(0);
+}
+
+void draw_selection_box(Shader shader, unsigned int vao, unsigned int vbo, int x, int y, float *transform) {
+  use_shader(shader);
+
+  set_mat4f(shader, "transform", transform);
+
+  glBindVertexArray(vao);
+
+  float vert = 0.11f;
+  // get size of a single cell in opengl coords (-1, 1)
+  float single_cell = (1.f/9.f) * 2;
+  // we minus 4 since we start at column and row 4 (0-indexed)
+  float offset_x = single_cell * (y - 4);
+  float offset_y = single_cell * (x - 4);
+
+  float vertices[6][2] = {
+    // top left tri
+    { -vert + offset_x, -vert - offset_y },
+    { -vert + offset_x,  vert - offset_y },
+    {  vert + offset_x,  vert - offset_y },
+
+    // bottom right tri
+    { -vert + offset_x, -vert - offset_y },
+    {  vert + offset_x,  vert - offset_y },
+    {  vert + offset_x, -vert - offset_y }
+  };
+
+  glBindBuffer(GL_ARRAY_BUFFER, vbo);
+  glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertices), vertices);
+
+  glBindBuffer(GL_ARRAY_BUFFER, 0);
+
+  glDrawArrays(GL_TRIANGLES, 0, 6);
+
+  glBindVertexArray(0);
+}
+
+void do_selection(Cudoku *game, int x, int y, int width, int height, float x_scale, float y_scale) {
+  float board_x_start = (width / 2.f) - ((width * x_scale) / 2);
+  float board_y_start = (height / 2.f) - ((height * y_scale) / 2);
+
+  float cell_width = (width * x_scale) / 9.f;
+  float cell_height = (height * y_scale) / 9.f;
+
+
+  int cell_x = floor((x - board_x_start) / cell_width);
+  int cell_y = floor((y - board_y_start) / cell_height);
+
+  if (cell_x < 0 || cell_x > 8 || cell_y < 0 || cell_y > 8) {
+    game->should_draw_selection = false;
+    return;
+  }
+
+  game->should_draw_selection = true;
+  game->selection.x = cell_y;
+  game->selection.y = cell_x;
+}
+
+void set_selected_number(Cudoku *game, int number) {
+  if (game->should_draw_selection) {
+    game->board[game->selection.x][game->selection.y] = number;
+  }
+}
+
+void move_selection(Cudoku *game, int x, int y) {
+  if (game->should_draw_selection) {
+    game->selection.x += y;
+    game->selection.y += x;
+
+    if (game->selection.x < 0) {
+      game->selection.x = 0;
+    } else if (game->selection.x > 8) {
+      game->selection.x = 8;
+    }
+
+    if (game->selection.y < 0) {
+      game->selection.y = 0;
+    } else if (game->selection.y > 8) {
+      game->selection.y = 8;
+    }
+  }
+}
+
+void toggle_selection(Cudoku *game) {
+  game->should_draw_selection = !game->should_draw_selection;
+}

cudoku.h

@@ -4,9 +4,27 @@
 
 #include "shader.h"
 
+typedef struct Vec2 {
+  int x;
+  int y;
+} Vec2;
+
+typedef struct Cudoku {
+  int board[9][9];
+  bool has_won;
+  Vec2 selection;
+  bool should_draw_selection;
+} Cudoku;
+
 void set_scale_factor(int width, int height, float *x, float *y);
 unsigned int prepare_bg(bool use_texture, unsigned int *texture);
 void draw_bg_grid_shader(Shader shader, unsigned int vao, float* transform, float resolution);
 void draw_bg_grid_texture(Shader shader, unsigned int vao, unsigned int texture, float* transform);
 void draw_numbers(Shader shader, unsigned int vao, unsigned int vbo, float *transform, int board[9][9]);
 void draw_win_overlay(Shader shader, unsigned int vao, unsigned int vbo, float *transform);
+void prepare_selection_box(unsigned int *vao, unsigned int *vbo);
+void draw_selection_box(Shader shader, unsigned int vao, unsigned int vbo, int x, int y, float *transform);
+void do_selection(Cudoku *game, int x, int y, int width, int height, float x_scale, float y_scale);
+void set_selected_number(Cudoku *game, int number);
+void move_selection(Cudoku *game, int x, int y);
+void toggle_selection(Cudoku *game);

font.c

@@ -36,7 +36,7 @@ int init_fonts(const char *font_path) {
 
   for (int i = 0; i < 9; i++) {
     if (FT_Load_Char(face, '0' + (i + 1), FT_LOAD_RENDER)) {
-      printf("Error: failed to load glyph for number '%c'\n", '0' + i);
+      printf("[ERROR]: failed to load glyph for number '%c'\n", '0' + i);
     }
 
     unsigned int texture;
@@ -61,7 +61,7 @@ int init_fonts(const char *font_path) {
 
   for (int c = 0; c < 128; c++) {
     if (FT_Load_Char(face, c, FT_LOAD_RENDER)) {
-      printf("Error: failed to load glyph for char '%c'\n", c);
+      printf("[ERROR]: failed to load glyph for char '%c'\n", c);
     }
 
     unsigned int texture;
@@ -164,6 +164,7 @@ void draw_number(Shader shader, int text, int row, int column, float scale, unsi
 
   glBindBuffer(GL_ARRAY_BUFFER, vbo);
   glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertices), vertices);
+
   glBindBuffer(GL_ARRAY_BUFFER, 0);
 
   glDrawArrays(GL_TRIANGLES, 0, 6);

main.c

@@ -10,6 +10,9 @@
 #include "cudoku.h"
 #include "font.h"
 
+Display *display;
+Window window;
+
 void usage() {
   printf("Usage: cudoku [OPTION]\n\n");
   printf("  %-20s%-20s", "-h, --help", "prints this help message\n");
@@ -17,8 +20,35 @@ void usage() {
   printf("  %-20s%-20s", "-f, --font FONT", "use a custom font file to render text\n");
 }
 
-Display *display;
-Window window;
+void handle_keypress(XEvent xev, Cudoku *game) {
+  if (XLookupKeysym(&xev.xkey, 0) == XK_r) {
+    /* reset_board(&game); */
+  } else if (XLookupKeysym(&xev.xkey, 0) >= XK_0 && XLookupKeysym(&xev.xkey, 0) <= XK_9) {
+    set_selected_number(game, XLookupKeysym(&xev.xkey, 0) - XK_0);
+  } else if (XLookupKeysym(&xev.xkey, 0) == XK_BackSpace || XLookupKeysym(&xev.xkey, 0) == XK_Delete) {
+    set_selected_number(game, 0);
+  } else if (XLookupKeysym(&xev.xkey, 0) == XK_Left || XLookupKeysym(&xev.xkey, 0) == XK_a || XLookupKeysym(&xev.xkey, 0) == XK_h) {
+    move_selection(game, -1, 0);
+  } else if (XLookupKeysym(&xev.xkey, 0) == XK_Right || XLookupKeysym(&xev.xkey, 0) == XK_d || XLookupKeysym(&xev.xkey, 0) == XK_l) {
+    move_selection(game, 1, 0);
+  } else if (XLookupKeysym(&xev.xkey, 0) == XK_Up || XLookupKeysym(&xev.xkey, 0) == XK_w || XLookupKeysym(&xev.xkey, 0) == XK_k) {
+    move_selection(game, 0, -1);
+  } else if (XLookupKeysym(&xev.xkey, 0) == XK_Down || XLookupKeysym(&xev.xkey, 0) == XK_s || XLookupKeysym(&xev.xkey, 0) == XK_j) {
+    move_selection(game, 0, 1);
+  } else if (XLookupKeysym(&xev.xkey, 0) == XK_Return || XLookupKeysym(&xev.xkey, 0) == XK_space) {
+    toggle_selection(game);
+  /* } else if (XLookupKeysym(&xev.xkey, 0) == XK_n) { */
+  /*   new_board(&game); */
+  /* } else if (XLookupKeysym(&xev.xkey, 0) == XK_f) { */
+  /*   toggle_fullscreen(display, window); */
+  /* } else if (XLookupKeysym(&xev.xkey, 0) == XK_c) { */
+  /*   toggle_check(&game); */
+  /* } else if (XLookupKeysym(&xev.xkey, 0) == XK_m) { */
+  /*   toggle_mute(&game); */
+  /* } else if (XLookupKeysym(&xev.xkey, 0) == XK_F1) { */
+  /*   toggle_help(&game); */
+  }
+}
 
 int main(int argc, char *argv[]) {
   const char *font_path = "assets/fonts/Rubik/Rubik-VariableFont_wght.ttf";
@@ -46,23 +76,31 @@ int main(int argc, char *argv[]) {
           font_path = argv[i + 1];
           i++;
         } else {
-          printf("Error: used font flag with no provided font, defaulting to Rubik\n");
+          printf("[ERROR]: used font flag with no provided font, defaulting to Rubik\n");
         }
       } else if (strcmp(flag, "--use-texture") == 0) {
-        use_texture = true;
+        FILE *fp = fopen("assets/sudoku-grid.png", "r");
+        if (fp == NULL) {
+          printf("[ERROR]: could not open board texture, falling back to shader grid\n");
+        } else {
+          fclose(fp);
+          use_texture = true;
+        }
       }
     }
   }
 
+  Cudoku game = {0};
+
   int res = init_x11(&display, &window);
   if (res < 0) return 1;
 
   res = init_fonts(font_path);
   if (res == -1) {
-    printf("Error: could not initialize freetype library\n");
+    printf("[ERROR]: could not initialize freetype library\n");
     return 1;
   } else if (res == -2) {
-    printf("Error: could not load font file: \"%s\"\n", font_path);
+    printf("[ERROR]: could not load font file: \"%s\"\n", font_path);
     return 1;
   }
 
@@ -77,31 +115,17 @@ int main(int argc, char *argv[]) {
   else
     grid_shader = create_shader("shaders/board_v.vert", "shaders/board_f.frag");
  
-  int vao = prepare_bg(use_texture, &grid_texture);
+  int board_vao = prepare_bg(use_texture, &grid_texture);
+
+  Shader selection_shader = create_shader("shaders/board_v.vert", "shaders/quad.frag");
+  unsigned int selection_vao, selection_vbo;
+  prepare_selection_box(&selection_vao, &selection_vbo);
 
-  int board[9][9] = {
-    {0, 0, 0, 0, 0, 0, 0, 0, 0},
-    {0, 0, 0, 0, 0, 0, 0, 0, 0},
-    {0, 0, 0, 0, 0, 0, 0, 0, 0},
-    {0, 0, 0, 0, 0, 0, 0, 0, 0},
-    {0, 0, 0, 0, 0, 0, 0, 0, 0},
-    {0, 0, 0, 0, 0, 0, 0, 0, 0},
-    {0, 0, 0, 0, 0, 0, 0, 0, 0},
-    {0, 0, 0, 0, 0, 0, 0, 0, 0},
-    {0, 0, 0, 0, 0, 0, 0, 0, 0},
-  };
   srand(time(NULL));
 
   for (int i = 0; i < 9; i++) {
     for (int j = 0; j < 9; j++) {
-      int r = (rand() % 9) + 1;
-      board[i][j] = r;
-    }
-  }
-
-  for (int i = 0; i < 9; i++) {
-    for (int j = 0; j < 9; j++) {
-      printf("%d | ", board[i][j]);
+      printf("%d | ", game.board[i][j]);
     }
     printf("\n");
   }
@@ -127,13 +151,14 @@ int main(int argc, char *argv[]) {
         if (XLookupKeysym(&xev.xkey, 0) == XK_Escape || XLookupKeysym(&xev.xkey, 0) == XK_q) {
           quit = true;
           break;
+        } else {
+          handle_keypress(xev, &game);
         }
       } else if (xev.type == ButtonPress) {
         if (xev.xbutton.button == Button1) {
           int x = xev.xbutton.x;
           int y = xev.xbutton.y;
-          // TOOD:
-          printf("x: %d, y: %d\n", x, y);
+          do_selection(&game, x, y, width, height, x_scale, y_scale);
         }
       }
     }
@@ -149,11 +174,18 @@ int main(int argc, char *argv[]) {
     };
 
     if (!use_texture)
-      draw_bg_grid_shader(grid_shader, vao, (float *)transform, width < height ? width : height);
+      draw_bg_grid_shader(grid_shader, board_vao, (float *)transform, width < height ? width : height);
     else
-      draw_bg_grid_texture(grid_shader, vao, grid_texture, (float *)transform);
-    /* draw_numbers(font_shader, font_vao, font_vbo, (float *)transform, board); */
-    draw_win_overlay(font_shader, font_vao, font_vbo, (float *)transform);
+      draw_bg_grid_texture(grid_shader, board_vao, grid_texture, (float *)transform);
+
+    if (game.should_draw_selection)
+      draw_selection_box(selection_shader, selection_vao, selection_vbo, game.selection.x, game.selection.y, (float *)transform);
+
+    draw_numbers(font_shader, font_vao, font_vbo, (float *)transform, game.board);
+
+    if (game.has_won) {
+      draw_win_overlay(font_shader, font_vao, font_vbo, (float *)transform);
+    }
 
     glXSwapBuffers(display, window);
   }

shaders/grid_f.frag

@@ -31,12 +31,13 @@ void main()
     bool isInsideGrid = isInsideGridHorizontally && isInsideGridVertically;
 
     // Determine if the current fragment is on a thicker grid line
-    bool isThickLineX = isInsideGrid && mod(fragCoordX, stepSize * 3) < 0.01;
-    bool isThickLineY = isInsideGrid && mod(fragCoordY, stepSize * 3) < 0.01;
+    bool isThickLineX = isInsideGrid && mod(fragCoordX, (stepSize + 0.0007) * 3) <= 0.01;
+    bool isThickLineY = isInsideGrid && mod(fragCoordY, (stepSize + 0.0007) * 3) <= 0.01;
 
     // Check if the current fragment is on a grid line
-    bool isGridX = isInsideGrid && mod(fragCoordX, stepSize) < 0.005;
-    bool isGridY = isInsideGrid && mod(fragCoordY, stepSize) < 0.005;
+    // 0.0007 to shift the grid lines a bit to the left
+    bool isGridX = isInsideGrid && mod(fragCoordX, stepSize + 0.0007) <= 0.005;
+    bool isGridY = isInsideGrid && mod(fragCoordY, stepSize + 0.0007) <= 0.005;
     
     // Set the fragment color based on whether it's a grid line or a thicker grid line
     if ((isThickLineX) || (isThickLineY)) {

shaders/quad.frag

@@ -0,0 +1,7 @@
+#version 330 core
+
+out vec4 FragColor;
+
+void main() {
+  FragColor = vec4(0.4, 0.4, 1.0, 0.5);
+}