Have slight issue with edge in self made triangle rasterizer C++ - c++

Question

The triangles are mostly ok but one or 2 triangles would have a missing pixel between them
which probably means theres a issue with edge cases but i cant figure it out
the white spaces only happen on the edge of the triangles so i assume there is something wrong with either my edge equation or my top left rule but im really lost on what is
wrong with it
struct EdgeEqn {
float a, b, c;
bool tl;
};
GLPbo::EdgeEqn construct(const glm::vec3 a, const glm::vec3& b) {
GLPbo::EdgeEqn x = { a.y - b.y,b.x - a.x,(b.y - a.y) * a.x - (b.x - a.x) * a.y };
if (x.a > 0) {
x.tl = true;
}
else if (x.a < 0) {
x.tl = false;
}
else if (x.b < 0) {
x.tl = true;
}
else {
x.tl = false;
}
return x;
}
bool edgeFunction(GLPbo::EdgeEqn x, const glm::vec2& c, float& line_eval)
{
float eval = x.a * c.x + x.b * c.y + x.c;
line_eval = eval;
return (eval > 0.f || (eval == 0.f && x.tl))
? true : false;
}
bool Topleft_increase(GLPbo::EdgeEqn x, float eval) {
return (eval > 0.f || (eval == 0.f && x.tl))
? true : false;
}
bool GLPbo::render_triangle(glm::vec3 const& p0, glm::vec3 const& p1,
glm::vec3 const& p2, glm::vec3 clr) {
if (((p1.x - p0.x) * (p2.y - p0.y) - (p2.x - p0.x) * (p1.y - p0.y)) < 0) {
culling++;
return false;
}
GLPbo::Color random = { static_cast<GLubyte>(clr.r), static_cast<GLubyte>(clr.g)
, static_cast<GLubyte>(clr.b), 255 };
int min_x = static_cast<int>(std::min({ p0.x, p1.x, p2.x }));
int min_y = static_cast<int>(std::min({ p0.y, p1.y, p2.y }));
int max_x = static_cast<int>(std::max({ p0.x, p1.x, p2.x }));
int max_y = static_cast<int>(std::max({ p0.y, p1.y, p2.y }));
GLPbo::EdgeEqn l0 = construct(p1, p2);
GLPbo::EdgeEqn l1 = construct(p2, p0);
GLPbo::EdgeEqn l2 = construct(p0, p1);
float ev0 = 0, ev1 = 0, ev2 = 0;
bool e0 = edgeFunction(l0, glm::vec2(min_x + 0.5, min_y + 0.5), ev0);
bool e1 = edgeFunction(l1, glm::vec2(min_x + 0.5, min_y + 0.5), ev1);
bool e2 = edgeFunction(l2, glm::vec2(min_x + 0.5, min_y + 0.5), ev2);
for (int y = min_y; y <= max_y; ++y) {
bool hE0 = e0; bool hE1 = e1; bool hE2 = e2;
float hEv0 = ev0; float hEv1 = ev1; float hEv2 = ev2;
for (int x = min_x; x <= max_x; ++x) {
if (hE0 == true && hE1 == true && hE2 == true) {
set_pixel(x, y, random);
}
hEv0 += l0.a;
hEv1 += l1.a;
hEv2 += l2.a;
hE0 = Topleft_increase(l0, hEv0);
hE1 = Topleft_increase(l1, hEv1);
hE2 = Topleft_increase(l2, hEv2);
}
ev0 += l0.b;
ev1 += l1.b;
ev2 += l2.b;
e0 = Topleft_increase(l0, ev0);
e1 = Topleft_increase(l1, ev1);
e2 = Topleft_increase(l2, ev2);
}
return true;
}