void RenderHelper::DrawPolygon( const Polygon2 & polygon, bool closed)
{
int ptCount = polygon.pointCount;
if (ptCount >= 2)
{
vertexStream->Set(TYPE_FLOAT, 2, 0, polygon.GetPoints());
RenderManager::Instance()->SetRenderEffect(RenderManager::FLAT_COLOR);
RenderManager::Instance()->SetRenderData(renderDataObject);
RenderManager::Instance()->DrawArrays(PRIMITIVETYPE_LINESTRIP, 0, ptCount);
if (closed)
{
Vector2 line[2] = {Vector2(polygon.GetPoints()[0]), Vector2(polygon.GetPoints()[ptCount-1])};
vertexStream->Set(TYPE_FLOAT, 2, 0, line);
RenderManager::Instance()->DrawArrays(PRIMITIVETYPE_LINESTRIP, 0, 2);
}
}
}
void RenderHelper::FillPolygon(const Polygon2 & polygon)
{
int ptCount = polygon.pointCount;
if (ptCount >= 3)
{
vertexStream->Set(TYPE_FLOAT, 2, 0, polygon.GetPoints());
RenderManager::Instance()->SetRenderEffect(RenderManager::FLAT_COLOR);
RenderManager::Instance()->SetRenderData(renderDataObject);
RenderManager::Instance()->DrawArrays(PRIMITIVETYPE_TRIANGLEFAN, 0, ptCount);
}
}
void Collisions::ProjectPolygon(const Vector2 & axis, Polygon2 & poly, float32 & min, float32 & max)
{
Vector2 * points = poly.GetPoints();
float32 proj = DotProduct(points[0], axis);
min = proj;
max = proj;
for (int32 pi = 1; pi < poly.GetPointCount(); ++pi)
{
proj = DotProduct(points[pi], axis);
if (proj < min)
min = proj;
if (proj > max)
max = proj;
}
}
void RenderHelper::DrawPolygonPoints(const Polygon2 & polygon)
{
int ptCount = polygon.pointCount;
if (ptCount >= 1)
{
#if defined (__DAVAENGINE_OPENGL__)
glPointSize(3.0f);
#endif
vertexStream->Set(TYPE_FLOAT, 2, 0, polygon.GetPoints());
RenderManager::Instance()->SetRenderEffect(RenderManager::FLAT_COLOR);
RenderManager::Instance()->SetRenderData(renderDataObject);
RenderManager::Instance()->DrawArrays(PRIMITIVETYPE_POINTLIST, 0, ptCount);
#if defined (__DAVAENGINE_OPENGL__)
glPointSize(1.0f);
#endif
}
}
bool Collisions::IsPolygonIntersectsPolygon(Polygon2 & poly1, Polygon2 & poly2)
{
//#define DEBUG_DRAW_INTERSECTIONS
Vector2 * points1 = poly1.GetPoints();
Vector2 * points2 = poly2.GetPoints();
separationAxes.clear();
for (int32 index1 = 0; index1 < poly1.pointCount; ++index1)
{
int32 index2 = (index1 + 1 != poly1.pointCount) ? (index1 + 1) : (0);
Vector2 line = points1[index2] - points1[index1];
Vector2 normal = Vector2(line.y, -line.x);
normal.Normalize();
AddSeparationAxis(normal);
#if defined(DEBUG_DRAW_INTERSECTIONS)
RenderManager::Instance()->SetColor(0.0f, 0.0f, 1.0f, 1.0f);
RenderHelper::DrawLine(points1[index1] + (line / 2), points1[index1] + (line / 2) + normal * 10);
#endif
}
for (int32 index1 = 0; index1 < poly2.pointCount; ++index1)
{
int32 index2 = (index1 + 1 != poly2.pointCount) ? (index1 + 1) : (0);
Vector2 line = points2[index2] - points2[index1];
Vector2 normal = Vector2(line.y, -line.x);
normal.Normalize();
AddSeparationAxis(normal);
#if defined(DEBUG_DRAW_INTERSECTIONS)
RenderManager::Instance()->SetColor(0.0f, 1.0f, 0.0f, 1.0f);
RenderHelper::DrawLine(points2[index1] + (line / 3), points2[index1] + (line / 3) + normal * 10);
#endif
}
size_t size = separationAxes.size();
#if defined(DEBUG_DRAW_INTERSECTIONS)
for (size_t index = 0; index < size; ++index)
{
Vector2 axis = separationAxes[index];
RenderManager::Instance()->SetColor(1.0f, 0.0f, 0.0f, 1.0f);
RenderHelper::DrawLine(Vector2(50.0f, 50.0f), Vector2(50.0f, 50.0f) + axis * 1000);
}
#endif
for (size_t index = 0; index < size; ++index)
{
Vector2 axis = separationAxes[index];
float32 p1Min, p1Max;
ProjectPolygon(axis, poly1, p1Min, p1Max);
float32 p2Min, p2Max;
ProjectPolygon(axis, poly2, p2Min, p2Max);
#if defined(DEBUG_DRAW_INTERSECTIONS)
RenderManager::Instance()->SetColor(0.0f, 1.0f, 1.0f, 1.0f);
Vector2 norm = Vector2(axis.y, -axis.x);
RenderHelper::DrawLine(Vector2(50.0f, 50.0f) + axis * p1Min + norm * 2.0f, Vector2(50.0f, 50.0f) + axis * p1Max + norm * 2.0f);
RenderManager::Instance()->SetColor(1.0f, 1.0f, 0.0f, 1.0f);
RenderHelper::DrawLine(Vector2(50.0f, 50.0f) + axis * p2Min - norm * 2.0f, Vector2(50.0f, 50.0f) + axis * p2Max - norm * 2.0f);
#endif
if (IntervalDistance(p1Min, p1Max, p2Min, p2Max) > 0)
return false;
}
return true;
}
