Freetype with opengl shows no text - c

Question

I’m trying to add freetype text to my running program. The code below was adapted from EdoardoLuciani. No text is shown, though.
I checked if the the tff file is loaded correctly and that valid textures ids are generated. They are o.k.
The remaining of the program is running without problem, but no text is drawn.
Could you help me to find what's wrong, please?
Environment:
DELL XPS
GPU 1050
OpenGL 4.6
Win32
Language C
// Main program
...
initText()
...
// Drawing loop
...
{
drawText(10, 300, "Hello World!");
}
void initText()
{
// Extract glyphs textures
//
glUseProgram(textShader);
FT_Library ft;
FT_Init_FreeType(&ft);
FT_Face face;
FT_New_Face(ft, "arial.ttf", 0, &face);
FT_Set_Pixel_Sizes(face, 0, 48);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
for(int c = 0; c < 128; c++)
{
FT_Load_Char(face, c, FT_LOAD_RENDER);
//
// Extract glyph
//
GLuint texture;
glCreateTextures(GL_TEXTURE_2D,1, &texture);
glTextureStorage2D(texture, 1, GL_R8, face->glyph->bitmap.width, face->glyph->bitmap.rows);
glTextureSubImage2D(texture, 0, 0, 0, face->glyph->bitmap.width, face->glyph->bitmap.rows, GL_RED, GL_UNSIGNED_BYTE, face->glyph->bitmap.buffer);
glBindTexture(GL_TEXTURE_2D, texture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glBindTexture(GL_TEXTURE_2D, 0);
//
// Save glyph to lookup table
//
Character ch;
ch.texture = texture;
ch.bearing[0] = face->glyph->bitmap.width;
ch.bearing[1] = face->glyph->bitmap.rows;
ch.size[0] = face->glyph->bitmap_left;
ch.size[1] = face->glyph->bitmap_top;
ch.advance = face->glyph->advance.x;
characters[c] = ch;
}
FT_Done_Face(face);
FT_Done_FreeType(ft);
//
// Create VAO
//
glCreateVertexArrays(1, &textVAO);
glBindVertexArray(textVAO);
//
// Create the unique VBO
//
glCreateBuffers(1, &VBO);
glNamedBufferStorage(VBO, sizeof(GLfloat) * 6 * 4, NULL, GL_DYNAMIC_STORAGE_BIT);
glVertexArrayVertexBuffer(textVAO, 0, VBO, 0, sizeof(GLfloat) * 4);
glVertexArrayAttribFormat(textVAO, 0, 4, GL_FLOAT, GL_FALSE, 0);
glVertexArrayAttribBinding(textVAO, 0, 0);
glEnableVertexArrayAttrib(textVAO, 0);
//
// Send color to fragment shader
//
glUniform3f(6, 0.88f, 0.59f, 0.07f);
}
void drawText(float x, float y, float scale, char *text)
{
glEnable(GL_CULL_FACE);
glUseProgram(textShader);
glBindVertexArray(textVAO);
//
// Draw each character
//
char *c = text;
while(*c != 0)
{
Character ch = characters[(int)*c];
if(ch.bearing[0] != 0 && ch.bearing[1] != 0)
{
GLfloat xpos = x + ch.bearing[0] * scale;
GLfloat ypos = y - (ch.size[1] - ch.bearing[1]) * scale;
//
GLfloat w = ch.size[0] * scale;
GLfloat h = ch.size[1] * scale;
//
// Update VBO for each character
//
GLfloat vertices[6*4] =
{
xpos, ypos + h, 0.0f, 0.0f ,
xpos, ypos, 0.0f, 1.0f ,
xpos + w, ypos, 1.0f, 1.0f ,
xpos, ypos + h, 0.0f, 0.0f ,
xpos + w, ypos, 1.0f, 1.0f ,
xpos + w, ypos + h, 1.0f, 0.0f
};
glNamedBufferSubData(VBO, 0, sizeof(GLfloat)*6*4, vertices);
glBindTexture(GL_TEXTURE_2D, ch.texture);
glDrawArrays(GL_TRIANGLES, 0, 6);
}
x += (ch.advance >> 6) * scale;
c++;
}
glDisable(GL_CULL_FACE);
}
The vertex shader:
#version 460 core
layout (location = 0) in vec4 vertex; // <vec2 pos, vec2 tex>
layout (location = 1) uniform mat4 projection;
out vec2 TexCoords;
void main()
{
gl_Position = projection * vec4(vertex.xy, 0.0, 1.0);
TexCoords = vertex.zw;
}
The fragment shader:
#version 460 core
in vec2 TexCoords;
out vec4 color;
layout (binding = 0) uniform sampler2D text;
layout (location = 6) uniform vec3 textColor;
void main()
{
color = vec4(textColor, 1.0) * texture(text, TexCoords).r;
}