diff options
author | Fox Caminiti <fox@foxcam.net> | 2022-12-16 20:16:43 -0500 |
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committer | Fox Caminiti <fox@foxcam.net> | 2022-12-16 20:16:43 -0500 |
commit | bedd6906eabdd513042d6a178d4dc56a3a41d1d3 (patch) | |
tree | 2bcbd3e46ae61e583707a2ccc5b3f5cfeacb61a8 /bezier.cpp | |
parent | cdb9e1f7240cb0716b7d99df5e1fd7c3fc3407a8 (diff) |
v3, file/build organization
Diffstat (limited to 'bezier.cpp')
-rw-r--r-- | bezier.cpp | 347 |
1 files changed, 0 insertions, 347 deletions
diff --git a/bezier.cpp b/bezier.cpp deleted file mode 100644 index 1a177c4..0000000 --- a/bezier.cpp +++ /dev/null @@ -1,347 +0,0 @@ - -static real32 -Bezier_SolveYForX(v2 Point_P0, v2 Point_P1, v2 Point_P2, v2 Point_P3, real32 TargetX) { - - real32 Y = 0; - - v2 m1 = (Point_P2 - Point_P0) / (2 * Tau); - v2 m2 = (Point_P3 - Point_P1) / (2 * Tau); - - real32 Precision = 0.000001; - real32 t = (TargetX - Point_P0.x) / (Point_P3.x - Point_P0.x); - - int Iterations = 0; - for (;;) { - real32 t2 = t * t; - real32 t3 = t2 * t; - real32 mt = 1-t; - real32 mt2 = mt * mt; - real32 mt3 = mt2 * mt; - v2 Point = (Point_P0 * mt3) + (3 * Point_P1 * mt2 * t) + (3 * Point_P2 * mt * t2) + (Point_P3 * t3); - - bool32 Cond1 = (Point.x <= (TargetX - Precision)); - bool32 Cond2 = (Point.x >= (TargetX + Precision)); - - if ((Cond1 || Cond2) && Iterations < 10) { - t = t * TargetX / Point.x; - Iterations++; - } else { - Y = Point.y; - break; - } - } - - return Y; -} - -#if 0 -// A modified version of the bezier code in ImGui with extra features for bitmap and path interaction. - -// Function to convert a ratio back into a point for the bezier handles. -v2 Line_RatioToPoint(v2 a, v2 b, real32 ratio) -{ - v2 ab_dir = b - a; - real32 ab_len_sqr = ab_dir.x * ab_dir.x + ab_dir.y * ab_dir.y; - real32 dot = ratio*ab_len_sqr; - return a + ab_dir * dot / V2(ab_len_sqr); -} - -// The ratio here is just the dot product divided by the squared length. -v2 Bezier_LineClosestPoint2(v2 a, v2 b, v2 p, real32 *ratio) -{ - v2 ap = p - a; - v2 ab_dir = b - a; - real32 dot = ap.x * ab_dir.x + ap.y * ab_dir.y; - if (dot < 0.0f) { - *ratio = 0.0f; - return a; - } - real32 ab_len_sqr = ab_dir.x * ab_dir.x + ab_dir.y * ab_dir.y; - if (dot > ab_len_sqr) { - *ratio = 1.0f; - return b; - } - *ratio = dot / ab_len_sqr; - return a + ab_dir * dot / ab_len_sqr; -} - -// Following the algorithm, we take the ratio from the _leftmost_ point in each -// subdivision of the cubic spline until we're within tess_tol, and then we -// interpolate it with the subdivision's rightmost point in the ClosestPoint call. -// The pow(0.5, level) represents the ratio of the next subdivision's leftmost -// point (AKA the rightmost point of the current subdivision). - -// finds the point closest to p and also fills out its ratio along the curve -static void Bezier_CubicClosestPointCasteljauStep(v2 p, v2 *p_closest, real32 ratio, real32 *r_closest, v2 *p_last, real32 *p_closest_dist2, - real32 x1, real32 y1, real32 x2, real32 y2, real32 x3, real32 y3, real32 x4, real32 y4, real32 tess_tol, int level) -{ - real32 dx = x4 - x1; - real32 dy = y4 - y1; - real32 d2 = ((x2 - x4) * dy - (y2 - y4) * dx); - real32 d3 = ((x3 - x4) * dy - (y3 - y4) * dx); - d2 = (d2 >= 0) ? d2 : -d2; - d3 = (d3 >= 0) ? d3 : -d3; - if ((d2 + d3) * (d2 + d3) < tess_tol * (dx * dx + dy * dy)) - { - v2 p_current = V2(x4, y4); - real32 added_ratio; - v2 p_line = Bezier_LineClosestPoint2(*p_last, p_current, p, &added_ratio); - real32 dist2 = LengthSq(p - p_line); - if (dist2 < *p_closest_dist2) - { - *p_closest = p_line; - *p_closest_dist2 = dist2; - *r_closest = ratio + pow(0.5, level)*added_ratio; - } - *p_last = p_current; - } - else if (level < 10) - { - real32 x12 = (x1 + x2)*0.5f, y12 = (y1 + y2)*0.5f; - real32 x23 = (x2 + x3)*0.5f, y23 = (y2 + y3)*0.5f; - real32 x34 = (x3 + x4)*0.5f, y34 = (y3 + y4)*0.5f; - real32 x123 = (x12 + x23)*0.5f, y123 = (y12 + y23)*0.5f; - real32 x234 = (x23 + x34)*0.5f, y234 = (y23 + y34)*0.5f; - real32 x1234 = (x123 + x234)*0.5f, y1234 = (y123 + y234)*0.5f; - Bezier_CubicClosestPointCasteljauStep(p, p_closest, ratio, r_closest, p_last, p_closest_dist2, x1, y1, x12, y12, x123, y123, x1234, y1234, tess_tol, level + 1); - Bezier_CubicClosestPointCasteljauStep(p, p_closest, ratio + pow(0.5, level+1), r_closest, p_last, p_closest_dist2, x1234, y1234, x234, y234, x34, y34, x4, y4, tess_tol, level + 1); - } -} - -// finds the min/max bounds of the curve -static void Bezier_CubicMinMaxCasteljauStep(v2 *p_min, v2 *p_max, real32 x1, real32 y1, real32 x2, real32 y2, real32 x3, real32 y3, real32 x4, real32 y4, real32 tess_tol, int level) -{ - real32 dx = x4 - x1; - real32 dy = y4 - y1; - real32 d2 = ((x2 - x4) * dy - (y2 - y4) * dx); - real32 d3 = ((x3 - x4) * dy - (y3 - y4) * dx); - d2 = (d2 >= 0) ? d2 : -d2; - d3 = (d3 >= 0) ? d3 : -d3; - if ((d2 + d3) * (d2 + d3) < tess_tol * (dx * dx + dy * dy)) - { - v2 p_current = V2(x4, y4); - if (p_current.x < p_min->x) { - p_min->x = p_current.x; - } - if (p_current.y < p_min->y) { - p_min->y = p_current.y; - } - if (p_current.x > p_max->x) { - p_max->x = p_current.x; - } - if (p_current.y > p_max->y) { - p_max->y = p_current.y; - } - } - else if (level < 10) - { - real32 x12 = (x1 + x2)*0.5f, y12 = (y1 + y2)*0.5f; - real32 x23 = (x2 + x3)*0.5f, y23 = (y2 + y3)*0.5f; - real32 x34 = (x3 + x4)*0.5f, y34 = (y3 + y4)*0.5f; - real32 x123 = (x12 + x23)*0.5f, y123 = (y12 + y23)*0.5f; - real32 x234 = (x23 + x34)*0.5f, y234 = (y23 + y34)*0.5f; - real32 x1234 = (x123 + x234)*0.5f, y1234 = (y123 + y234)*0.5f; - Bezier_CubicMinMaxCasteljauStep(p_min, p_max, x1, y1, x12, y12, x123, y123, x1234, y1234, tess_tol, level + 1); - Bezier_CubicMinMaxCasteljauStep(p_min, p_max, x1234, y1234, x234, y234, x34, y34, x4, y4, tess_tol, level + 1); - } -} - -// return all points -static void Bezier_CubicCalcPointsCasteljauStep(void *Data, uint32 *Increment, real32 x1, real32 y1, real32 x2, real32 y2, real32 x3, real32 y3, real32 x4, real32 y4, real32 tess_tol, int level) -{ - real32 dx = x4 - x1; - real32 dy = y4 - y1; - real32 d2 = ((x2 - x4) * dy - (y2 - y4) * dx); - real32 d3 = ((x3 - x4) * dy - (y3 - y4) * dx); - d2 = (d2 >= 0) ? d2 : -d2; - d3 = (d3 >= 0) ? d3 : -d3; - if ((d2 + d3) * (d2 + d3) < tess_tol * (dx * dx + dy * dy)) - { - *((real32 *)Data + *Increment*3) = x4; - *((real32 *)Data + *Increment*3 + 1) = y4; - *((real32 *)Data + *Increment*3 + 2) = 0; - *Increment += 1; - } - else if (level < 10) - { - real32 x12 = (x1 + x2)*0.5f, y12 = (y1 + y2)*0.5f; - real32 x23 = (x2 + x3)*0.5f, y23 = (y2 + y3)*0.5f; - real32 x34 = (x3 + x4)*0.5f, y34 = (y3 + y4)*0.5f; - real32 x123 = (x12 + x23)*0.5f, y123 = (y12 + y23)*0.5f; - real32 x234 = (x23 + x34)*0.5f, y234 = (y23 + y34)*0.5f; - real32 x1234 = (x123 + x234)*0.5f, y1234 = (y123 + y234)*0.5f; - Bezier_CubicCalcPointsCasteljauStep(Data, Increment, x1, y1, x12, y12, x123, y123, x1234, y1234, tess_tol, level + 1); - Bezier_CubicCalcPointsCasteljauStep(Data, Increment, x1234, y1234, x234, y234, x34, y34, x4, y4, tess_tol, level + 1); - } -} - -real32 Bezier_CubicRatioOfPoint(v2 p1, v2 p2, v2 p3, v2 p4, v2 p) -{ - real32 tess_tol = TESS_TOL; - v2 p_last = p1; - v2 p_closest; - real32 p_closest_dist2 = FLT_MAX; - real32 ratio = 0; - Bezier_CubicClosestPointCasteljauStep(p, &p_closest, 0, &ratio, &p_last, &p_closest_dist2, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, p4.x, p4.y, tess_tol, 0); - return ratio; -} - -void Bezier_CubicCalcPoints(v2 p1, v2 p2, v2 p3, v2 p4, void *Data, uint32 *Increment) -{ - real32 tess_tol = TESS_TOL; - void *Pointer = Data; - Bezier_CubicCalcPointsCasteljauStep(Pointer, Increment, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, p4.x, p4.y, tess_tol, 0); -} - -// These functions will become more generalized as shapes are added. - -static void -Mask_AddPointToLine(mask *Mask, uint16 Index, v2 Pos) -{ - for (int i = Mask->NumberOfPoints - 1; i > Index; i--) { - Mask->Point[i+1] = Mask->Point[i]; - } - mask_point *PointToAdd = &Mask->Point[Index+1]; - PointToAdd->Pos = Pos; - Mask->NumberOfPoints++; -} - -static void -Mask_PushPoint(mask *Mask, v2 Pos) -{ - mask_point *PointToAdd = &Mask->Point[Mask->NumberOfPoints]; - PointToAdd->Pos = Pos; - Mask->NumberOfPoints++; -} - -static void -Mask_ShiftPointers(mask *Mask, int16 Increment, int16 StopAt) { - if (Increment > 0) { - int16 i = Mask->NumberOfPoints - 1; - while (i >= StopAt) { - mask_point *CurrentPoint = &Mask->Point[i]; - mask_point *NextPoint = &Mask->Point[i + Increment]; - *NextPoint = *CurrentPoint; - i--; - } - } else { - int16 i = StopAt; - while (i <= Mask->NumberOfPoints - 1) { - mask_point *CurrentPoint = &Mask->Point[i]; - mask_point *NextPoint = &Mask->Point[i - Increment]; - *CurrentPoint = *NextPoint; - i++; - } - } -} - -static void -Mask_DeletePoint(memory *Memory, mask *Mask, uint16 Index) -{ - History_Entry_Commit(Memory, action_entry_default, "Delete keyframe"); - mask_point *MaskPointIndex = &Mask->Point[Index]; - History_Action_StoreData(Memory, MaskPointIndex, sizeof(mask_point)); - - History_Action_Change_Decrement(Memory, &Mask->NumberOfPoints, action_type_change_u16); - // History_Action_Shift(Memory, action_type_shift_bezier, Mask, -1, Index); - void *StartingAddress = &Mask->Point[0]; - History_Action_Shift_2(Memory, StartingAddress, sizeof(mask_point), Mask->NumberOfPoints, -1, Index); - // Mask_ShiftPointers(Mask, -1, Index); - History_Entry_End(Memory); -} - -// It's more useful to input the ratio here instead of the cursor position -// since we have to use it to calculate the four new handle lengths (two on the -// new point and one on each edge). -static void -Mask_AddPointToCurve(memory *Memory, mask *Mask, uint16 Index, real32 ratio) -{ - mask_point *Point0 = &Mask->Point[Index]; - mask_point *Point1 = &Mask->Point[Index+1]; - if (Index + 1 == Mask->NumberOfPoints) - Point1 = &Mask->Point[0]; - - v2 Point0_Pos_Right = Point0->Pos + Point0->TangentRight; - v2 Point1_Pos_Left = Point1->Pos + Point1->TangentLeft; - v2 Handle0_Half = Line_RatioToPoint(Point0->Pos, Point0_Pos_Right, ratio); - v2 Handle1_Half = Line_RatioToPoint(Point1_Pos_Left, Point1->Pos, ratio); - v2 Top_Half = Line_RatioToPoint(Point0_Pos_Right, Point1_Pos_Left, ratio); - v2 NewHandleLeft = Line_RatioToPoint(Handle0_Half, Top_Half, ratio); - v2 NewHandleRight = Line_RatioToPoint(Top_Half, Handle1_Half, ratio); - v2 NewPos = Line_RatioToPoint(NewHandleLeft, NewHandleRight, ratio); - - History_Entry_Commit(Memory, action_entry_default, "Add point to curve"); - - v2 NewPoint0Pos = -(Point0->Pos - Handle0_Half); - v2 NewPoint1Pos = -(Point1->Pos - Handle1_Half); - History_Action_Change_V2(Memory, &Point0->TangentRight, &Point0->TangentRight, &NewPoint0Pos); - History_Action_Change_V2(Memory, &Point1->TangentLeft, &Point1->TangentLeft, &NewPoint1Pos); - - void *StartingAddress = &Mask->Point[0]; - History_Action_Shift_2(Memory, StartingAddress, sizeof(mask_point), Mask->NumberOfPoints, 1, Index); - - mask_point *PointToAdd = &Mask->Point[Index+1]; - - // NOTE(fox): The above shift duplicates the keyframe at Index into where - // we're writing, Index+1. I'm using the Change action (which is normally - // for changing values that already exist) on this intermediate keyframe - // slot to save having to write a bunch of special actions for shifting and - // adding new data. - - History_Action_Change_V2(Memory, &PointToAdd->Pos, &PointToAdd->Pos, &NewPos); - v2 NewLeftPos = -(NewPos - NewHandleLeft); - v2 NewRightPos = -(NewPos - NewHandleRight); - History_Action_Change_V2(Memory, &PointToAdd->TangentLeft, &PointToAdd->TangentLeft, &NewLeftPos); - History_Action_Change_V2(Memory, &PointToAdd->TangentRight, &PointToAdd->TangentRight, &NewRightPos); - - History_Action_Change_Increment(Memory, &Mask->NumberOfPoints, action_type_change_u16); - History_Entry_End(Memory); -} - -static void -Mask_RasterizePoints(mask *Mask) -{ - Mask->NumberOfVerts = 0; - for (int i = 0; i < Mask->NumberOfPoints; i++) { - mask_point Point0 = Mask->Point[i]; - mask_point Point1 = Mask->Point[i+1]; - if (i+1 == Mask->NumberOfPoints) - Point1 = Mask->Point[0]; - - if (Point0.HandleBezier && Point1.HandleBezier) { - Bezier_CubicCalcPoints(Point0.Pos, Point0.Pos + Point0.TangentRight, Point1.Pos + Point1.TangentLeft, Point1.Pos, - Mask->TriangulatedPointCache, &Mask->NumberOfVerts); - } else if (Point0.HandleBezier) { - Bezier_CubicCalcPoints(Point0.Pos, Point0.Pos + Point0.TangentRight, Point1.Pos, Point1.Pos, - Mask->TriangulatedPointCache, &Mask->NumberOfVerts); - } else if (Point1.HandleBezier) { - Bezier_CubicCalcPoints(Point0.Pos, Point0.Pos, Point1.Pos + Point1.TangentLeft, Point1.Pos, - Mask->TriangulatedPointCache, &Mask->NumberOfVerts); - } else { - real32 *Data = (real32 *)Mask->TriangulatedPointCache + Mask->NumberOfVerts*3; - *(Data++) = Point0.Pos.x; - *(Data++) = Point0.Pos.y; - *(Data++) = 0; - // NOTE(fox): CubicCalcPoints sometimes misses generating the start - // point of the next path in the above two cases, so I'm making - // straight lines always add both points as a hotfix. This leads - // to cases of duplicate verts, but it doesn't seem like it harms - // the rendering in any way. - *(Data++) = Point1.Pos.x; - *(Data++) = Point1.Pos.y; - *(Data++) = 0; - Mask->NumberOfVerts += 2; - } - } -} - -void Mask_TriangulateAndRasterize(memory *Memory, project_layer *Layer, mask *Mask) -{ - if (!Mask->TriangulatedPointCache) { - Mask->TriangulatedPointCache = AllocateMemory(Memory, 50*1024, P_VectorPoints); - } - Mask_RasterizePoints(Mask); - - GL_RasterizeShape(Layer, Mask); -} -#endif |