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Batch::tri_line implemented

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This commit is contained in:
Noel Berry 2020-10-11 13:48:45 -07:00
parent 02a9272b29
commit 1af8669441
1 changed files with 36 additions and 18 deletions
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54
public/blah/drawing/batch.cpp
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@ -54,6 +54,19 @@ const VertexAttribute attributes[4] = {
{ 3, VertexSemantics::Texcoord1, VertexAttributeType::Byte, 3, true },
};
namespace
{
static Vec2 batch_shape_intersection(const Vec2& p0, const Vec2& p1, const Vec2& q0, const Vec2& q1)
{
const auto aa = p1 - p0;
const auto bb = q0 - q1;
const auto cc = q0 - p0;
const auto t = (bb.x * cc.y - bb.y * cc.x) / (aa.y * bb.x - aa.x * bb.y);
return Vec2(p0.x + t * (p1.x - p0.x), p0.y + t * (p1.y - p0.y));
}
}
#define MAKE_VERTEX(vert, mat, px, py, tx, ty, c, m, w, f) \
(vert)->pos.x = ((px) * mat.m11) + ((py) * mat.m21) + mat.m31; \
(vert)->pos.y = ((px) * mat.m12) + ((py) * mat.m22) + mat.m32; \
@ -418,7 +431,25 @@ void Batch::tri(const Vec2& pos0, const Vec2& pos1, const Vec2& pos2, const Vec2
void Batch::tri_line(const Vec2& a, const Vec2& b, const Vec2& c, float t, Color color)
{
BLAH_ASSERT(false, "Method 'tri_line' Not Implemented");
// TODO:
// Detect if the thickness of the line fills the entire shape
// (in which case, draw a triangle instead)
const float len_ab = (a - b).length();
const float len_bc = (b - c).length();
const float len_ca = (c - a).length();
const auto off_ab = ((b - a) / len_ab).turn_left() * t;
const auto off_bc = ((c - b) / len_bc).turn_left() * t;
const auto off_ca = ((a - c) / len_ca).turn_left() * t;
const auto aa = batch_shape_intersection(a + off_ca, a + off_ca, a + off_ab, b + off_ab);
const auto bb = batch_shape_intersection(a + off_ab, b + off_ab, b + off_bc, c + off_bc);
const auto cc = batch_shape_intersection(b + off_bc, c + off_bc, c + off_ca, a + off_ca);
quad(aa, a, b, bb, color);
quad(bb, b, c, cc, color);
quad(cc, c, a, aa, color);
}
void Batch::rect(const Rect& rect, Color color)
@ -684,19 +715,6 @@ void Batch::quad(const Vec2& pos0, const Vec2& pos1, const Vec2& pos2, const Vec
m_tex_mult, m_tex_wash, 0);
}
namespace
{
static Vec2 batch_quad_intersection(const Vec2& p0, const Vec2& p1, const Vec2& q0, const Vec2& q1)
{
const auto aa = p1 - p0;
const auto bb = q0 - q1;
const auto cc = q0 - p0;
const auto t = (bb.x * cc.y - bb.y * cc.x) / (aa.y * bb.x - aa.x * bb.y);
return Vec2(p0.x + t * (p1.x - p0.x), p0.y + t * (p1.y - p0.y));
}
}
void Batch::quad_line(const Vec2& a, const Vec2& b, const Vec2& c, const Vec2& d, float t, Color color)
{
// TODO:
@ -713,10 +731,10 @@ void Batch::quad_line(const Vec2& a, const Vec2& b, const Vec2& c, const Vec2& d
const auto off_cd = ((d - c) / len_cd).turn_left() * t;
const auto off_da = ((a - d) / len_da).turn_left() * t;
const auto aa = batch_quad_intersection(d + off_da, a + off_da, a + off_ab, b + off_ab);
const auto bb = batch_quad_intersection(a + off_ab, b + off_ab, b + off_bc, c + off_bc);
const auto cc = batch_quad_intersection(b + off_bc, c + off_bc, c + off_cd, d + off_cd);
const auto dd = batch_quad_intersection(c + off_cd, d + off_cd, d + off_da, a + off_da);
const auto aa = batch_shape_intersection(d + off_da, a + off_da, a + off_ab, b + off_ab);
const auto bb = batch_shape_intersection(a + off_ab, b + off_ab, b + off_bc, c + off_bc);
const auto cc = batch_shape_intersection(b + off_bc, c + off_bc, c + off_cd, d + off_cd);
const auto dd = batch_shape_intersection(c + off_cd, d + off_cd, d + off_da, a + off_da);
quad(aa, a, b, bb, color);
quad(bb, b, c, cc, color);