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Merge branch 'master' into docking

This commit is contained in:
ocornut 2024-03-05 18:12:11 +01:00
commit fd75685fb0
7 changed files with 388 additions and 34 deletions

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@ -8,6 +8,7 @@ Index of this file:
// [SECTION] STB libraries implementation
// [SECTION] Style functions
// [SECTION] ImDrawList
// [SECTION] ImTriangulator, ImDrawList concave polygon fill
// [SECTION] ImDrawListSplitter
// [SECTION] ImDrawData
// [SECTION] Helpers ShadeVertsXXX functions
@ -1706,6 +1707,316 @@ void ImDrawList::AddImageRounded(ImTextureID user_texture_id, const ImVec2& p_mi
PopTextureID();
}
//-----------------------------------------------------------------------------
// [SECTION] ImTriangulator, ImDrawList concave polygon fill
//-----------------------------------------------------------------------------
// Triangulate concave polygons. Based on "Triangulation by Ear Clipping" paper, O(N^2) complexity.
// Reference: https://www.geometrictools.com/Documentation/TriangulationByEarClipping.pdf
// Provided as a convenience for user but not used by main library.
//-----------------------------------------------------------------------------
// - ImTriangulator [Internal]
// - AddConcavePolyFilled()
//-----------------------------------------------------------------------------
enum ImTriangulatorNodeType
{
ImTriangulatorNodeType_Convex,
ImTriangulatorNodeType_Ear,
ImTriangulatorNodeType_Reflex
};
struct ImTriangulatorNode
{
ImTriangulatorNodeType Type;
int Index;
ImVec2 Pos;
ImTriangulatorNode* Next;
ImTriangulatorNode* Prev;
void Unlink() { Next->Prev = Prev; Prev->Next = Next; }
};
struct ImTriangulatorNodeSpan
{
ImTriangulatorNode** Data = NULL;
int Size = 0;
void push_back(ImTriangulatorNode* node) { Data[Size++] = node; }
void find_erase_unsorted(int idx) { for (int i = Size - 1; i >= 0; i--) if (Data[i]->Index == idx) { Data[i] = Data[Size - 1]; Size--; return; } }
};
struct ImTriangulator
{
static int EstimateTriangleCount(int points_count) { return (points_count < 3) ? 0 : points_count - 2; }
static int EstimateScratchBufferSize(int points_count) { return sizeof(ImTriangulatorNode) * points_count + sizeof(ImTriangulatorNode*) * points_count * 2; }
void Init(const ImVec2* points, int points_count, void* scratch_buffer);
void GetNextTriangle(unsigned int out_triangle[3]); // Return relative indexes for next triangle
// Internal functions
void BuildNodes(const ImVec2* points, int points_count);
void BuildReflexes();
void BuildEars();
void FlipNodeList();
bool IsEar(int i0, int i1, int i2, const ImVec2& v0, const ImVec2& v1, const ImVec2& v2) const;
void ReclassifyNode(ImTriangulatorNode* node);
// Internal members
int _TrianglesLeft = 0;
ImTriangulatorNode* _Nodes = NULL;
ImTriangulatorNodeSpan _Ears;
ImTriangulatorNodeSpan _Reflexes;
};
// Distribute storage for nodes, ears and reflexes.
// FIXME-OPT: if everything is convex, we could report it to caller and let it switch to an convex renderer
// (this would require first building reflexes to bail to convex if empty, without even building nodes)
void ImTriangulator::Init(const ImVec2* points, int points_count, void* scratch_buffer)
{
IM_ASSERT(scratch_buffer != NULL && points_count >= 3);
_TrianglesLeft = EstimateTriangleCount(points_count);
_Nodes = (ImTriangulatorNode*)scratch_buffer; // points_count x Node
_Ears.Data = (ImTriangulatorNode**)(_Nodes + points_count); // points_count x Node*
_Reflexes.Data = (ImTriangulatorNode**)(_Nodes + points_count) + points_count; // points_count x Node*
BuildNodes(points, points_count);
BuildReflexes();
BuildEars();
}
void ImTriangulator::BuildNodes(const ImVec2* points, int points_count)
{
for (int i = 0; i < points_count; i++)
{
_Nodes[i].Type = ImTriangulatorNodeType_Convex;
_Nodes[i].Index = i;
_Nodes[i].Pos = points[i];
_Nodes[i].Next = _Nodes + i + 1;
_Nodes[i].Prev = _Nodes + i - 1;
}
_Nodes[0].Prev = _Nodes + points_count - 1;
_Nodes[points_count - 1].Next = _Nodes;
}
void ImTriangulator::BuildReflexes()
{
ImTriangulatorNode* n1 = _Nodes;
for (int i = _TrianglesLeft; i >= 0; i--, n1 = n1->Next)
{
if (ImTriangleIsClockwise(n1->Prev->Pos, n1->Pos, n1->Next->Pos))
continue;
n1->Type = ImTriangulatorNodeType_Reflex;
_Reflexes.push_back(n1);
}
}
void ImTriangulator::BuildEars()
{
ImTriangulatorNode* n1 = _Nodes;
for (int i = _TrianglesLeft; i >= 0; i--, n1 = n1->Next)
{
if (n1->Type != ImTriangulatorNodeType_Convex)
continue;
if (!IsEar(n1->Prev->Index, n1->Index, n1->Next->Index, n1->Prev->Pos, n1->Pos, n1->Next->Pos))
continue;
n1->Type = ImTriangulatorNodeType_Ear;
_Ears.push_back(n1);
}
}
void ImTriangulator::GetNextTriangle(unsigned int out_triangle[3])
{
if (_Ears.Size == 0)
{
FlipNodeList();
ImTriangulatorNode* node = _Nodes;
for (int i = _TrianglesLeft; i >= 0; i--, node = node->Next)
node->Type = ImTriangulatorNodeType_Convex;
_Reflexes.Size = 0;
BuildReflexes();
BuildEars();
// If we still don't have ears, it means geometry is degenerated.
if (_Ears.Size == 0)
{
// Return first triangle available, mimicking the behavior of convex fill.
IM_ASSERT(_TrianglesLeft > 0); // Geometry is degenerated
_Ears.Data[0] = _Nodes;
_Ears.Size = 1;
}
}
ImTriangulatorNode* ear = _Ears.Data[--_Ears.Size];
out_triangle[0] = ear->Prev->Index;
out_triangle[1] = ear->Index;
out_triangle[2] = ear->Next->Index;
ear->Unlink();
if (ear == _Nodes)
_Nodes = ear->Next;
ReclassifyNode(ear->Prev);
ReclassifyNode(ear->Next);
_TrianglesLeft--;
}
void ImTriangulator::FlipNodeList()
{
ImTriangulatorNode* prev = _Nodes;
ImTriangulatorNode* temp = _Nodes;
ImTriangulatorNode* current = _Nodes->Next;
prev->Next = prev;
prev->Prev = prev;
while (current != _Nodes)
{
temp = current->Next;
current->Next = prev;
prev->Prev = current;
_Nodes->Next = current;
current->Prev = _Nodes;
prev = current;
current = temp;
}
_Nodes = prev;
}
// A triangle is an ear is no other vertex is inside it. We can test reflexes vertices only (see reference algorithm)
bool ImTriangulator::IsEar(int i0, int i1, int i2, const ImVec2& v0, const ImVec2& v1, const ImVec2& v2) const
{
ImTriangulatorNode** p_end = _Reflexes.Data + _Reflexes.Size;
for (ImTriangulatorNode** p = _Reflexes.Data; p < p_end; p++)
{
ImTriangulatorNode* reflex = *p;
if (reflex->Index != i0 && reflex->Index != i1 && reflex->Index != i2)
if (ImTriangleContainsPoint(v0, v1, v2, reflex->Pos))
return false;
}
return true;
}
void ImTriangulator::ReclassifyNode(ImTriangulatorNode* n1)
{
// Classify node
ImTriangulatorNodeType type;
const ImTriangulatorNode* n0 = n1->Prev;
const ImTriangulatorNode* n2 = n1->Next;
if (!ImTriangleIsClockwise(n0->Pos, n1->Pos, n2->Pos))
type = ImTriangulatorNodeType_Reflex;
else if (IsEar(n0->Index, n1->Index, n2->Index, n0->Pos, n1->Pos, n2->Pos))
type = ImTriangulatorNodeType_Ear;
else
type = ImTriangulatorNodeType_Convex;
// Update lists when a type changes
if (type == n1->Type)
return;
if (n1->Type == ImTriangulatorNodeType_Reflex)
_Reflexes.find_erase_unsorted(n1->Index);
else if (n1->Type == ImTriangulatorNodeType_Ear)
_Ears.find_erase_unsorted(n1->Index);
if (type == ImTriangulatorNodeType_Reflex)
_Reflexes.push_back(n1);
else if (type == ImTriangulatorNodeType_Ear)
_Ears.push_back(n1);
n1->Type = type;
}
// Use ear-clipping algorithm to triangulate a simple polygon (no self-interaction, no holes).
// (Reminder: we don't perform any coarse clipping/culling in ImDrawList layer!
// It is up to caller to ensure not making costly calls that will be outside of visible area.
// As concave fill is noticeably more expensive than other primitives, be mindful of this...
// Caller can build AABB of points, and avoid filling if 'draw_list->_CmdHeader.ClipRect.Overlays(points_bb) == false')
void ImDrawList::AddConcavePolyFilled(const ImVec2* points, const int points_count, ImU32 col)
{
if (points_count < 3 || (col & IM_COL32_A_MASK) == 0)
return;
const ImVec2 uv = _Data->TexUvWhitePixel;
ImTriangulator triangulator;
unsigned int triangle[3];
if (Flags & ImDrawListFlags_AntiAliasedFill)
{
// Anti-aliased Fill
const float AA_SIZE = _FringeScale;
const ImU32 col_trans = col & ~IM_COL32_A_MASK;
const int idx_count = (points_count - 2) * 3 + points_count * 6;
const int vtx_count = (points_count * 2);
PrimReserve(idx_count, vtx_count);
// Add indexes for fill
unsigned int vtx_inner_idx = _VtxCurrentIdx;
unsigned int vtx_outer_idx = _VtxCurrentIdx + 1;
_Data->TempBuffer.reserve_discard((ImTriangulator::EstimateScratchBufferSize(points_count) + sizeof(ImVec2)) / sizeof(ImVec2));
triangulator.Init(points, points_count, _Data->TempBuffer.Data);
while (triangulator._TrianglesLeft > 0)
{
triangulator.GetNextTriangle(triangle);
_IdxWritePtr[0] = (ImDrawIdx)(vtx_inner_idx + (triangle[0] << 1)); _IdxWritePtr[1] = (ImDrawIdx)(vtx_inner_idx + (triangle[1] << 1)); _IdxWritePtr[2] = (ImDrawIdx)(vtx_inner_idx + (triangle[2] << 1));
_IdxWritePtr += 3;
}
// Compute normals
_Data->TempBuffer.reserve_discard(points_count);
ImVec2* temp_normals = _Data->TempBuffer.Data;
for (int i0 = points_count - 1, i1 = 0; i1 < points_count; i0 = i1++)
{
const ImVec2& p0 = points[i0];
const ImVec2& p1 = points[i1];
float dx = p1.x - p0.x;
float dy = p1.y - p0.y;
IM_NORMALIZE2F_OVER_ZERO(dx, dy);
temp_normals[i0].x = dy;
temp_normals[i0].y = -dx;
}
for (int i0 = points_count - 1, i1 = 0; i1 < points_count; i0 = i1++)
{
// Average normals
const ImVec2& n0 = temp_normals[i0];
const ImVec2& n1 = temp_normals[i1];
float dm_x = (n0.x + n1.x) * 0.5f;
float dm_y = (n0.y + n1.y) * 0.5f;
IM_FIXNORMAL2F(dm_x, dm_y);
dm_x *= AA_SIZE * 0.5f;
dm_y *= AA_SIZE * 0.5f;
// Add vertices
_VtxWritePtr[0].pos.x = (points[i1].x - dm_x); _VtxWritePtr[0].pos.y = (points[i1].y - dm_y); _VtxWritePtr[0].uv = uv; _VtxWritePtr[0].col = col; // Inner
_VtxWritePtr[1].pos.x = (points[i1].x + dm_x); _VtxWritePtr[1].pos.y = (points[i1].y + dm_y); _VtxWritePtr[1].uv = uv; _VtxWritePtr[1].col = col_trans; // Outer
_VtxWritePtr += 2;
// Add indexes for fringes
_IdxWritePtr[0] = (ImDrawIdx)(vtx_inner_idx + (i1 << 1)); _IdxWritePtr[1] = (ImDrawIdx)(vtx_inner_idx + (i0 << 1)); _IdxWritePtr[2] = (ImDrawIdx)(vtx_outer_idx + (i0 << 1));
_IdxWritePtr[3] = (ImDrawIdx)(vtx_outer_idx + (i0 << 1)); _IdxWritePtr[4] = (ImDrawIdx)(vtx_outer_idx + (i1 << 1)); _IdxWritePtr[5] = (ImDrawIdx)(vtx_inner_idx + (i1 << 1));
_IdxWritePtr += 6;
}
_VtxCurrentIdx += (ImDrawIdx)vtx_count;
}
else
{
// Non Anti-aliased Fill
const int idx_count = (points_count - 2) * 3;
const int vtx_count = points_count;
PrimReserve(idx_count, vtx_count);
for (int i = 0; i < vtx_count; i++)
{
_VtxWritePtr[0].pos = points[i]; _VtxWritePtr[0].uv = uv; _VtxWritePtr[0].col = col;
_VtxWritePtr++;
}
_Data->TempBuffer.reserve_discard((ImTriangulator::EstimateScratchBufferSize(points_count) + sizeof(ImVec2)) / sizeof(ImVec2));
triangulator.Init(points, points_count, _Data->TempBuffer.Data);
while (triangulator._TrianglesLeft > 0)
{
triangulator.GetNextTriangle(triangle);
_IdxWritePtr[0] = (ImDrawIdx)(_VtxCurrentIdx + triangle[0]); _IdxWritePtr[1] = (ImDrawIdx)(_VtxCurrentIdx + triangle[1]); _IdxWritePtr[2] = (ImDrawIdx)(_VtxCurrentIdx + triangle[2]);
_IdxWritePtr += 3;
}
_VtxCurrentIdx += (ImDrawIdx)vtx_count;
}
}
//-----------------------------------------------------------------------------
// [SECTION] ImDrawListSplitter