Files
panopainter/engine/shape.hpp
2017-01-18 19:42:34 +00:00

113 lines
3.8 KiB
C++

#pragma once
class Shape
{
protected:
GLuint buffers[2];
GLuint arrays[2];
GLuint count[2];
GLvoid* ioff[2];
struct vertex_t { glm::vec4 pos; glm::vec2 uvs; };
public:
bool create_buffers(GLvoid* idx, GLvoid* vertices, int isize, int vsize);
void draw_fill() const;
void draw_stroke() const;
protected:
glm::vec2 quad_mid_point(glm::vec2 a, glm::vec2 b, glm::vec2 c, glm::vec2 d)
{
float den = (a.x-c.x)*(b.y-d.y) - (a.y-c.y)*(b.x-d.x);
float numx = (a.x*c.y-a.y*c.x)*(b.x-d.x) - (a.x-c.x)*(b.x*d.y-b.y*d.x);
float numy = (a.x*c.y-a.y*c.x)*(b.y-d.y) - (a.y-c.y)*(b.x*d.y-b.y*d.x);
return glm::vec2(numx, numy) / den;
}
void adjust_quad_uvs(vertex_t& va, vertex_t& vb, vertex_t& vc, vertex_t& vd)
{
static float d[4];
static vertex_t* v[4];
v[0] = &va; v[1] = &vb; v[2] = &vc; v[3] = &vc;
auto mid = quad_mid_point(va.pos, vb.pos, vc.pos, vd.pos);
for (int i = 0; i < 4; i++)
d[i] = glm::distance(glm::vec2(v[i]->pos), mid);
for (int i = 0; i < 4; i++)
{
float q = (d[i] + d[(i + 2) % 4]) / d[(i + 2) % 4];
v[i]->uvs = glm::vec4(glm::vec2(v[i]->uvs), 0, 1) * q;
}
}
};
class Plane : public Shape
{
void create_impl(float w, float h, int div, GLushort* idx, vertex_t* vertices);
public:
template<int div>
bool create(float w, float h)
{
static GLushort idx[div * div * 6 + 8];
static vertex_t vertices[(div+1)*(div+1)];
create_impl(w, h, div, idx, vertices);
return create_buffers(idx, vertices, sizeof(idx), sizeof(vertices));
}
};
class Circle : public Shape
{
public:
enum class kUVMapping: uint8_t { Planar, Tube };
template<int div>
bool create(float radius)
{
static GLushort idx[div*3 + div*2];
static vertex_t vertices[div+1];
create_impl(radius, div, idx, vertices);
return create_buffers(idx, vertices, sizeof(idx), sizeof(vertices));
}
template<int div>
bool create(float radius, kUVMapping map)
{
static GLushort idx[(div+1)*3 + (div+1)*4];
static vertex_t vertices[(div+1)*2];
create_impl(radius, 0.f, (div+1), idx, vertices, map);
return create_buffers(idx, vertices, sizeof(idx), sizeof(vertices));
}
template<int div>
bool create(float radius_out, float radius_in, kUVMapping map)
{
static GLushort idx[(div+1)*6 + (div+1)*4];
static vertex_t vertices[(div+1) * 2];
create_impl(radius_out, radius_in, (div+1), idx, vertices, map);
return create_buffers(idx, vertices, sizeof(idx), sizeof(vertices));
}
private:
void create_impl(float radius, int div, GLushort* idx, vertex_t* vertices);
void create_impl(float radius_out, float radius_in, int div, GLushort* idx, vertex_t* vertices, kUVMapping map);
};
class Rounded : public Shape
{
void create_impl(float w, float h, float r, int div, GLushort* idx, GLushort* idx_tmp, vertex_t* vertices);
public:
template<int div>
bool create(float w, float h, float r)
{
static GLushort idx[(10 + div * 4) * 3 + (4 + div * 4) * 2];
static GLushort idx_tmp[div+1];
static vertex_t vertices[12 + (div-1) * 4];
create_impl(w, h, r, div, idx, idx_tmp, vertices);
return create_buffers(idx, vertices, sizeof(idx), sizeof(vertices));
}
};
class Slice9 : public Shape
{
void create_impl(float w, float h, float r, float tr, GLushort* idx, vertex_t* vertices);
public:
bool create(float w, float h, float r, float tr)
{
static GLushort idx[3 * 3 * 6 + 4 * 2];
static vertex_t vertices[4 * 4];
create_impl(w, h, r, tr, idx, vertices);
return create_buffers(idx, vertices, sizeof(idx), sizeof(vertices));
}
};