Use triangle fan for text rendering

.gitignore

@@ -1,4 +1,5 @@
 hexnando
 hexnando.exe
+imgui.ini
 *.pdb
 *.ilk

imgui.ini

@@ -1,20 +0,0 @@
-[Window][Debug##Default]
-Pos=38,60
-Size=400,400
-Collapsed=0
-
-[Window][Dear ImGui Demo]
-Pos=33,236
-Size=550,680
-Collapsed=0
-
-[Window][Hi there]
-Pos=138,172
-Size=422,452
-Collapsed=0
-
-[Table][0xC9935533,3]
-Column 0  Weight=1.0000
-Column 1  Weight=1.0000
-Column 2  Weight=1.0000
-

main.cpp

@@ -236,7 +236,6 @@ uint32_t make_gl_program(const char *pathname_vertex, const char *pathname_fragm
 
 void render_text(const char *text, float x, float y, float scale, glm::vec3 color)
 {
-    // TODO: Use triangle strip (4 vertices vs 6)
     // TODO: Group draw calls together instead of doing 1 draw call/character. Use an atlas with GL_TEXTURE_ARRAY
     // TODO: Do not make draw calls for invisible characters!
   
@@ -258,14 +257,11 @@ void render_text(const char *text, float x, float y, float scale, glm::vec3 colo
         float w = charglyph.size.x * scale;
         float h = charglyph.size.y * scale;
         // update VBO for each character
-        float vertices[6][4] = {
+        float vertices[4][4] = {
           { xpos,     ypos + h,   0.0f, 0.0f },            
           { xpos,     ypos,       0.0f, 1.0f },
           { xpos + w, ypos,       1.0f, 1.0f },
-
+          { xpos + w, ypos + h,   1.0f, 0.0f }
-          { xpos,     ypos + h,   0.0f, 0.0f },
-          { xpos + w, ypos,       1.0f, 1.0f },
-          { xpos + w, ypos + h,   1.0f, 0.0f }           
         };
         // render glyph texture over quad
         glBindTexture(GL_TEXTURE_2D, charglyph.tex);
@@ -274,7 +270,9 @@ void render_text(const char *text, float x, float y, float scale, glm::vec3 colo
         glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertices), vertices); 
         glBindBuffer(GL_ARRAY_BUFFER, 0);
         // render quad
-        glDrawArrays(GL_TRIANGLES, 0, 6);
+        glEnable(GL_CULL_FACE);
+        glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+        glDisable(GL_CULL_FACE);
         // now advance cursors for next glyph (note that advance is number of 1/64 pixels)
         x += (charglyph.advance >> 6) * scale; // bitshift by 6 to get value in pixels (2^6 = 64)
     }
@@ -488,6 +486,7 @@ int main([[maybe_unused]]int argc, [[maybe_unused]]char **argv)
     camera_t the_camera;
     bool mouse_pressed;
     bool mouse_over_gui;
+    static bool show_hex_numbers = true;
     static selection_t selection;
     selection.indices = (int32_t*)calloc(1, sizeof(int32_t) * grid.rows * grid.columns);
     selection.nselected = 0;
@@ -640,8 +639,8 @@ int main([[maybe_unused]]int argc, [[maybe_unused]]char **argv)
             TIME_BLOCK(text_render);
             stbsp_snprintf(debug_text_buf, 256, "Cursor position %.0f %.0f screen %.2f %.2f world", cursor_x, cursor_y, cursor_world.x, cursor_world.y);
             render_text(debug_text_buf, 25, 25, .5f, glm::vec3(1.0f, 1.0f, 1.0f));
-        
+
-            for (int i = 0; i < grid.rows * grid.columns; ++i)
+            for (int i = 0; show_hex_numbers && i < grid.rows * grid.columns; ++i)
             {
                 // Get position of hexes in screen
                 glm::vec4 v = glm::vec4(grid.hexes[i].position.x, grid.hexes[i].position.y, grid.hexes[i].position.z, 1.0);
@@ -650,6 +649,9 @@ int main([[maybe_unused]]int argc, [[maybe_unused]]char **argv)
                 v.x *= window_width/2.0f;
                 v.y += 1;
                 v.y *= window_height/2.0f;
+                // Do not draw text outside visible window
+                if (v.x > window_width || v.x < 0 || v.y > window_height || v.y < 0)
+                    continue;
                 char number_string[11];
                 stbsp_snprintf(number_string, 11, "%d", i);
                 render_text(number_string, v.x, v.y, .2f + (0.3f / the_camera.size.x), glm::vec3(0.0f, 0.0f, 0.0f));
@@ -667,7 +669,7 @@ int main([[maybe_unused]]int argc, [[maybe_unused]]char **argv)
 
         static int grid_rows = grid.rows;
         static int grid_columns = grid.columns;
-
+        
         if (grid_rows != grid.rows || grid_columns != grid.columns)
         {
             create_grid(&grid, grid_rows, grid_columns);
@@ -682,6 +684,7 @@ int main([[maybe_unused]]int argc, [[maybe_unused]]char **argv)
             ImGui::Begin("Hi there");
             ImGui::SliderInt("Rows", &grid_rows, 1, 100);
             ImGui::SliderInt("Columns", &grid_columns, 1, 100);
+            ImGui::Checkbox("Show hex numbers", &show_hex_numbers);
             if (ImGui::CollapsingHeader("Debug timers"))
             {
                 for (int i = 0; i < ntimers; ++i)