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diff --git a/src/bezier.cpp b/src/bezier.cpp
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+
+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;
+}
+
+static bezier_point *
+Bezier_LookupAddress(memory *Memory, property_channel *Property, uint16 Index, bool32 AssertExists)
+{
+ Assert(Index < MAX_KEYFRAMES_PER_BLOCK); // TODO(fox): Test multiple keyframe blocks!
+ block_bezier *Bezier = (block_bezier *)Memory_Block_AddressAtIndex(Memory, F_Bezier, Property->Block_Bezier_Index[0], AssertExists);
+ return &Bezier->Point[Index];
+}
+
+static void
+Bezier_Interact_Evaluate(project_state *State, bezier_point *PointAddress, v2 *Pos, real32 GraphZoomHeight, real32 Y_Increment)
+{
+ Pos[0] = PointAddress->Pos[0];
+ Pos[1] = PointAddress->Pos[1];
+ Pos[2] = PointAddress->Pos[2];
+ if (PointAddress->IsSelected) {
+ if (State->Interact_Active == interact_type_keyframe_move) {
+ if (State->Interact_Modifier != 2)
+ Pos[PointAddress->IsSelected - 1].x += (int32)State->Interact_Offset[0];
+ if (State->Interact_Modifier != 1)
+ Pos[PointAddress->IsSelected - 1].y -= (State->Interact_Offset[1] / GraphZoomHeight / Y_Increment);
+ } else if (State->Interact_Active == interact_type_keyframe_scale) {
+ Pos[1].x += State->Interact_Offset[0];
+ Pos[2].x -= State->Interact_Offset[0];
+ } else if (State->Interact_Active == interact_type_keyframe_rotate) {
+ // how do I do this??
+ Assert(0);
+ }
+ }
+}
+
+static void
+Bezier_Add(memory *Memory, memory_table_list TableName, property_channel *Property, bezier_point PointData, uint16 *ArrayLocation)
+{
+ if (!Property->Block_Bezier_Count) {
+ // TODO(fox): Test multiple keyframe blocks!
+ Assert(Property->Keyframe_Count < MAX_KEYFRAMES_PER_BLOCK);
+ Property->Block_Bezier_Index[0] = Memory_Block_AllocateNew(Memory, F_Bezier);
+ block_bezier *Bezier = (block_bezier *)Memory_Block_AddressAtIndex(Memory, F_Bezier, Property->Block_Bezier_Index[0], 0);
+ Bezier->Occupied = true;
+ History_Action_Swap(Memory, TableName, sizeof(Property->Block_Bezier_Count), &Property->Block_Bezier_Count);
+ Property->Block_Bezier_Count++;
+ }
+ // First check to see if the point to add overlaps an existing keyframe:
+ if (ArrayLocation) {
+ for (int p = 0; p < Property->Keyframe_Count; p++) {
+ int k = ArrayLocation[p];
+ bezier_point *Point = Bezier_LookupAddress(Memory, Property, k);
+ if (Point->Pos[0].x == PointData.Pos[0].x) {
+ History_Action_Swap(Memory, F_Bezier, sizeof(*Point), Point);
+ *Point = PointData;
+ return;
+ }
+ }
+ }
+ int k = 0;
+ for (;;) {
+ bezier_point *Point = Bezier_LookupAddress(Memory, Property, k, 0);
+ if (!Point->Occupied) {
+ History_Action_Swap(Memory, F_Bezier, sizeof(*Point), Point);
+ *Point = PointData;
+ History_Action_Swap(Memory, TableName, sizeof(Property->Keyframe_Count), &Property->Keyframe_Count);
+ Property->Keyframe_Count++;
+ return;
+ }
+ k++;
+ }
+}
+
+#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
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