circles, triangles and rotations for primitive shapes

cudoku.c

@@ -63,14 +63,26 @@ void draw_win() {
 
   Sizef text_size = calculate_text_size(win_text, font_size);
 
-  set_x_constraint(&constraints, 0, UI_CONSTRAINT_FIXED);
+  set_x_constraint(&constraints, 50, UI_CONSTRAINT_FIXED);
   set_y_constraint(&constraints, 0, UI_CONSTRAINT_FIXED);
-  set_width_constraint(&constraints, 200, UI_CONSTRAINT_FIXED);
+  set_width_constraint(&constraints, 50, UI_CONSTRAINT_FIXED);
-  set_height_constraint(&constraints, 200, UI_CONSTRAINT_FIXED);
+  set_height_constraint(&constraints, 50, UI_CONSTRAINT_FIXED);
 
-  draw_quad(constraints, &bg_color, 100.00, ALIGN_TOP_LEFT);
+  UIConstraints circle_const;
-  draw_quad(constraints, &bg_color, 0.50, ALIGN_BOTTOM_RIGHT);
+  set_x_constraint(&circle_const, 50, UI_CONSTRAINT_FIXED);
-  draw_quad(constraints, &bg_color, 0.0, align);
+  set_y_constraint(&circle_const, 0, UI_CONSTRAINT_FIXED);
+  set_width_constraint(&circle_const, 70, UI_CONSTRAINT_FIXED);
+  set_height_constraint(&circle_const, 90, UI_CONSTRAINT_FIXED);
+
+/*   draw_circle(circle_const, NULL, ALIGN_LEFT_CENTER); */
+  /* draw_quad(constraints, &bg_color, 0.0, ALIGN_TOP_LEFT); */
+/*   set_x_constraint(&constraints, -50, UI_CONSTRAINT_FIXED); */
+/*   draw_quad(constraints, &bg_color, 25.0, ALIGN_TOP_RIGHT); */
+/*   set_x_constraint(&constraints, 0, UI_CONSTRAINT_FIXED); */
+/*   draw_quad(constraints, &bg_color, 0.5, ALIGN_BOTTOM_RIGHT); */
+/*   draw_quad(constraints, &bg_color, 0.0, align); */
+
+  /* draw_triangle(constraints, &bg_color, ALIGN_CENTER); */
 
   draw_text(win_text, font_size, (Vec2f){0.0, 0.0}, &text_color, align);
 }

helper.c

@@ -1,3 +1,5 @@
+#include <math.h>
+
 #include "helper.h"
 
 Matrix4x4 identity() {
@@ -11,6 +13,34 @@ Matrix4x4 identity() {
     return result;
 }
 
+void mult_4x4(Matrix4x4 *multiplicant, Matrix4x4 *multiplier) {
+  Matrix4x4 result = identity();
+
+  for (int i = 0; i < 4; i++) {
+    for (int j = 0; j < 4; j++) {
+      result.m[i][j] = 0;
+      for (int k = 0; k < 4; k++) {
+        result.m[i][j] += multiplicant->m[i][k] * multiplier->m[k][j];
+      }
+    }
+  }
+
+  *multiplicant = result;
+}
+
+// TODO: rotate around the center of the element
+// currently we rotate around the 0, 0 point of the element
+void apply_rotation(Matrix4x4 *model, float angle) {
+  Matrix4x4 ident = identity();
+
+  ident.m[0][0] = cos(angle);
+  ident.m[0][1] = sin(angle);
+  ident.m[1][0] = -sin(angle);
+  ident.m[1][1] = cos(angle);
+
+  mult_4x4(model, &ident);
+}
+
 Matrix4x4 orthographic_projection_2d(float left, float right, float bottom, float top) {
     Matrix4x4 result = identity();
 
@@ -41,3 +71,7 @@ float clampf(float value, float min, float max) {
 
     return value;
 }
+
+float to_radians(float degrees) {
+  return degrees * (M_PI / 180.f);
+}

helper.h

@@ -5,7 +5,10 @@ typedef struct {
 } Matrix4x4;
 
 Matrix4x4 identity();
+void mult_4x4(Matrix4x4 *multiplicant, Matrix4x4 *multiplier);
+void apply_rotation(Matrix4x4 *model, float angle);
 Matrix4x4 orthographic_projection_2d(float left, float right, float bottom, float top);
 int max(int a, int b);
 float maxf(float a, float b);
 float clampf(float value, float min, float max);
+float to_radians(float degrees);

todo.txt

@@ -1,4 +1,6 @@
-- draw functions for other primitive shapes (circle, triangle?)
+- rotations/scaling for text (fix the code for it)
+
+- maybe force the window to be a specific resolution
 - border decorations for shapes
 - look into SDF/vector text
 - unicode support?

ui.c

@@ -369,16 +369,10 @@ void draw_quad(UIConstraints constraints, Color *color, float border_radius, Ali
     set_vec4f(ui_shader, "aColor", 0.f, 0.f, 0.f, 1.f);
   }
 
-  printf("width: %f, height: %f\n", constraints.width, constraints.height);
   set_float(ui_shader, "uiWidth", constraints.width);
   set_float(ui_shader, "uiHeight", constraints.height);
   set_float(ui_shader, "borderRadius", border_radius);
   set_mat4f(ui_shader, "projection", (float *)zephr_context.projection.m);
-  Matrix4x4 model = identity();
-
-  set_mat4f(font_shader, "model", (float *)model.m);
-
-  glBindVertexArray(ui_vao);
 
   Vec2f pos = { 0.f, 0.f };
   Sizef size = { 0.f, 0.f };
@@ -386,16 +380,25 @@ void draw_quad(UIConstraints constraints, Color *color, float border_radius, Ali
   apply_constraints(constraints, &pos, &size);
   apply_alignment(align, &pos, size);
 
+  Matrix4x4 model = identity();
+  apply_rotation(&model, to_radians(0));
+  model.m[3][0] = pos.x;
+  model.m[3][1] = pos.y;
+
+  set_mat4f(font_shader, "model", (float *)model.m);
+
+  glBindVertexArray(ui_vao);
+
   float vertices[6][4] = {
     // bottom left tri
-    {pos.x,              pos.y + size.height, 0.0, 1.0},
+    {0,              0 + size.height, 0.0, 1.0},
-    {pos.x,              pos.y,               0.0, 0.0},
+    {0,              0,               0.0, 0.0},
-    {pos.x + size.width, pos.y,               1.0, 0.0},
+    {0 + size.width, 0,               1.0, 0.0},
 
     // top right tri
-    {pos.x,              pos.y + size.height, 0.0, 1.0},
+    {0,              0 + size.height, 0.0, 1.0},
-    {pos.x + size.width, pos.y,               1.0, 0.0},
+    {0 + size.width, 0,               1.0, 0.0},
-    {pos.x + size.width, pos.y + size.height, 1.0, 1.0},
+    {0 + size.width, 0 + size.height, 1.0, 1.0},
   };
 
   glBindBuffer(GL_ARRAY_BUFFER, ui_vbo);
@@ -407,6 +410,57 @@ void draw_quad(UIConstraints constraints, Color *color, float border_radius, Ali
   glBindVertexArray(0);
 }
 
+void draw_circle(UIConstraints constraints, Color *color, Alignment align) {
+  float radius = 0.f;
+
+  if (constraints.width > constraints.height) {
+    radius = constraints.height / 2.f;
+  } else {
+    radius = constraints.width / 2.f;
+  }
+  draw_quad(constraints, color, radius, align);
+}
+
+void draw_triangle(UIConstraints constraints, Color *color, Alignment align) {
+  use_shader(ui_shader);
+
+  if (color) {
+    set_vec4f(ui_shader, "aColor", color->r / 255.f, color->g / 255.f, color->b / 255.f, color->a / 255.f);
+  } else {
+    set_vec4f(ui_shader, "aColor", 0.f, 0.f, 0.f, 1.f);
+  }
+  set_mat4f(ui_shader, "projection", (float *)zephr_context.projection.m);
+
+  Vec2f pos = { 0.f, 0.f };
+  Sizef size = { 0.f, 0.f };
+
+  apply_constraints(constraints, &pos, &size);
+  apply_alignment(align, &pos, size);
+
+  Matrix4x4 model = identity();
+  apply_rotation(&model, to_radians(0));
+  model.m[3][0] = pos.x;
+  model.m[3][1] = pos.y;
+
+  set_mat4f(font_shader, "model", (float *)model.m);
+
+  glBindVertexArray(ui_vao);
+
+  float vertices[3][4] = {
+    {0 + size.width,     0,               0.0, 0.0},
+    {0,                  0,               0.0, 0.0},
+    {0 + size.width / 2, 0 + size.height, 0.0, 0.0},
+  };
+
+  glBindBuffer(GL_ARRAY_BUFFER, ui_vbo);
+  glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertices), vertices);
+  glBindBuffer(GL_ARRAY_BUFFER, 0);
+
+  glDrawArrays(GL_TRIANGLES, 0, 3);
+
+  glBindVertexArray(0);
+}
+
 void draw_text(const char* text, int font_size, Vec2f pos, Color *color, Alignment alignment) {
   use_shader(font_shader);
   if (color) {
@@ -421,9 +475,6 @@ void draw_text(const char* text, int font_size, Vec2f pos, Color *color, Alignme
 
   set_mat4f(font_shader, "model", (float *)model.m);
 
-  glActiveTexture(GL_TEXTURE0);
-  glBindVertexArray(font_vao);
-
   Sizef text_size = calculate_text_size(text, FONT_PIXEL_SIZE);
   float font_scale = (float)font_size / FONT_PIXEL_SIZE;
 
@@ -435,6 +486,9 @@ void draw_text(const char* text, int font_size, Vec2f pos, Color *color, Alignme
 
   float first_char_bearing_w = characters[(int)text[0]].bearing.width;
 
+  glActiveTexture(GL_TEXTURE0);
+  glBindVertexArray(font_vao);
+
   int c = 0;
   int x = 0;
   while (text[c] != '\0') {

ui.h

@@ -82,5 +82,7 @@ void set_y_constraint(UIConstraints *constraints, float value, UIConstraint type
 void set_width_constraint(UIConstraints *constraints, float value, UIConstraint type);
 void set_height_constraint(UIConstraints *constraints, float value, UIConstraint type);
 void draw_quad(UIConstraints constraints, Color *color, float border_radius, Alignment align);
+void draw_circle(UIConstraints constraints, Color *color, Alignment align);
+void draw_triangle(UIConstraints constraints, Color *color, Alignment align);
 void draw_text(const char* text, int font_size, Vec2f pos, Color *color, Alignment align);
 Sizef calculate_text_size(const char *text, int font_size);