1 files changed, 38 insertions, 6 deletions

diff --git a/intern/smoke/intern/smoke_API.cpp b/intern/smoke/intern/smoke_API.cpp
index 427f4d53171..168395f370d 100644
--- a/intern/smoke/intern/smoke_API.cpp
+++ b/intern/smoke/intern/smoke_API.cpp
@@ -33,10 +33,10 @@
 #include <math.h>
 
 // y in smoke is z in blender
-extern "C" FLUID_3D *smoke_init(int *res, float *p0, float dt)
+extern "C" FLUID_3D *smoke_init(int *res, float *p0)
 {
 	// smoke lib uses y as top-bottom/vertical axis where blender uses z
-	FLUID_3D *fluid = new FLUID_3D(res, p0, dt);
+	FLUID_3D *fluid = new FLUID_3D(res, p0);
 
 	// printf("xres: %d, yres: %d, zres: %d\n", res[0], res[1], res[2]);
 
@@ -75,9 +75,41 @@ extern "C" size_t smoke_get_index2d(int x, int max_x, int y /*, int max_y, int z
 	return x + y * max_x;
 }
 
-extern "C" void smoke_step(FLUID_3D *fluid, size_t framenr)
+extern "C" void smoke_step(FLUID_3D *fluid, size_t framenr, float fps)
 {
-	fluid->step();
+	/* stability values copied from wturbulence.cpp */
+	const int maxSubSteps = 25;
+	const float maxVel = 0.5f; /* TODO: maybe 0.5 is still too high, please confirm! -dg */
+
+	float dt = DT_DEFAULT;
+	float maxVelMag = 0.0f;
+	int totalSubsteps;
+	int substep = 0;
+	float dtSubdiv;
+
+	/* get max velocity and lower the dt value if it is too high */
+	size_t size= fluid->_xRes * fluid->_yRes * fluid->_zRes;
+
+	for(size_t i = 0; i < size; i++)
+	{
+		float vtemp = (fluid->_xVelocity[i]*fluid->_xVelocity[i]+fluid->_yVelocity[i]*fluid->_yVelocity[i]+fluid->_zVelocity[i]*fluid->_zVelocity[i]);
+		if(vtemp > maxVelMag)
+			maxVelMag = vtemp;
+	}
+
+	/* adapt timestep for different framerates, dt = 0.1 is at 25fps */
+	dt *= (25.0f / fps);
+
+	maxVelMag = sqrt(maxVelMag) * dt * (*(fluid->_dtFactor));
+	totalSubsteps = (int)((maxVelMag / maxVel) + 1.0f); /* always round up */
+	totalSubsteps = (totalSubsteps < 1) ? 1 : totalSubsteps;
+	totalSubsteps = (totalSubsteps > maxSubSteps) ? maxSubSteps : totalSubsteps;
+	dtSubdiv = (float)dt / (float)totalSubsteps;
+
+	// printf("totalSubsteps: %d, maxVelMag: %f, dt: %f\n", totalSubsteps, maxVelMag, dt);
+
+	for(substep = 0; substep < totalSubsteps; substep++)
+		fluid->step(dtSubdiv);
 }
 
 extern "C" void smoke_turbulence_step(WTURBULENCE *wt, FLUID_3D *fluid)
@@ -85,9 +117,9 @@ extern "C" void smoke_turbulence_step(WTURBULENCE *wt, FLUID_3D *fluid)
 	wt->stepTurbulenceFull(fluid->_dt/fluid->_dx, fluid->_xVelocity, fluid->_yVelocity, fluid->_zVelocity, fluid->_obstacles); 
 }
 
-extern "C" void smoke_initBlenderRNA(FLUID_3D *fluid, float *alpha, float *beta)
+extern "C" void smoke_initBlenderRNA(FLUID_3D *fluid, float *alpha, float *beta, float *dt_factor, float *vorticity, int *border_colli)
 {
-	fluid->initBlenderRNA(alpha, beta);
+	fluid->initBlenderRNA(alpha, beta, dt_factor, vorticity, border_colli);
 }
 
 extern "C" void smoke_dissolve(FLUID_3D *fluid, int speed, int log)