Fixed Constraint projection code in perspective mode. When using a planar constraints, it follows the movement of the mouse exactly instead of just casting on the plane.

In user terms: the motion on screen of the selection follows the motion of the mouse pointer.

Gives some errors when the constraint plane is nearly perpendicular to the view port though.

Added a debug print function for 4D vectors to arithb.c

Optimised the 3D -> view projection functions in view.c (a bit).

source/blender/blenlib/BLI_arithb.h

@@ -478,6 +478,11 @@ sasqrt(
 printvecf(
 	char *str,
 	float v[3]
+);
+	void
+printvec4f(
+	char *str,
+	float v[4]
 );
 	float 
 Inpf(

source/blender/blenlib/intern/arithb.c

@@ -961,6 +961,14 @@ void printvecf( char *str,  float v[3])
 
 }
 
+void printvec4f( char *str,  float v[4])
+{
+	printf("%s\n", str);
+	printf("%f %f %f %f\n",v[0],v[1],v[2], v[3]);
+	printf("\n");
+
+}
+
 void printmatrix4( char *str,  float m[][4])
 {
 	printf("%s\n", str);

source/blender/src/transform.c

@@ -1285,17 +1285,20 @@ void Transform(int mode)
 					else if (G.qual == LR_CTRLKEY)
 						setConstraint(&Trans, mati, (APPLYCON|CONAXIS1|CONAXIS2));
 					break;
+					Trans.redraw = 1;
 				case YKEY:
 					if (G.qual == 0)
 						setConstraint(&Trans, mati, (APPLYCON|CONAXIS1));
 					else if (G.qual == LR_CTRLKEY)
 						setConstraint(&Trans, mati, (APPLYCON|CONAXIS0|CONAXIS2));
 					break;
+					Trans.redraw = 1;
 				case ZKEY:
 					if (G.qual == 0)
 						setConstraint(&Trans, mati, (APPLYCON|CONAXIS2));
 					else if (G.qual == LR_CTRLKEY)
 						setConstraint(&Trans, mati, (APPLYCON|CONAXIS0|CONAXIS1));
+					Trans.redraw = 1;
 					break;
 				case OKEY:
 					if (G.qual==LR_SHIFTKEY) {

source/blender/src/transform_constraints.c

@@ -114,8 +114,36 @@ void recalcData();
 /* ************************** CONSTRAINTS ************************* */
 void getConstraintMatrix(TransInfo *t);
 
-void axisProjection(float axis[3], float in[3], float out[3]) {
+void getViewVector(TransInfo *t, float coord[3], float vec[3]) {
-	float n[3], vec[3], factor;
+	if (G.vd->persp)
+	{
+		float p1[4], p2[4];
+
+		VecAddf(p1, coord, t->con.center);
+		p1[3] = 1.0f;
+		VECCOPY(p2, p1);
+		p2[3] = 1.0f;
+		Mat4MulVec4fl(G.vd->viewmat, p2);
+
+		p2[0] = 2.0f * p2[0];
+		p2[1] = 2.0f * p2[1];
+		p2[2] = 2.0f * p2[2];
+
+		Mat4MulVec4fl(G.vd->viewinv, p2);
+
+		VecSubf(vec, p2, p1);
+		Normalise(vec);
+	}
+	else {
+		VECCOPY(vec, G.vd->viewinv[2]);
+	}
+}
+
+void axisProjection(TransInfo *t, float axis[3], float in[3], float out[3]) {
+	float norm[3], n[3], vec[3], factor;
+
+	getViewVector(t, in, norm);
+
 	Normalise(axis);
 
 	VECCOPY(n, axis);
@@ -123,31 +151,33 @@ void axisProjection(float axis[3], float in[3], float out[3]) {
 	n[2] = G.vd->viewmat[3][2];
 	Mat4MulVecfl(G.vd->viewinv, n);
 
-	if (Inpf(axis, G.vd->viewinv[2]) != 1.0f) {
+	if (Inpf(axis, norm) != 1.0f) {
 		Projf(vec, in, n);
 		factor = Normalise(vec);
 		factor /= Inpf(axis, vec);
 
 		VecMulf(axis, factor);
 		VECCOPY(out, axis);
-
 	}
 	else {
 		out[0] = out[1] = out[2] = 0.0f;
 	}
 }
 
-void planeProjection(float in[3], float out[3]) {
+void planeProjection(TransInfo *t, float in[3], float out[3]) {
-	float vec[3], factor, angle;
+	float vec[3], factor, angle, norm[3];
+
+	getViewVector(t, in, norm);
 
 	VecSubf(vec, out, in);
 	factor = Normalise(vec);
-	angle = Inpf(vec, G.vd->viewinv[2]);
+	angle = Inpf(vec, norm);
+
 
 	if (angle * angle >= 0.000001f) {
 		factor /= angle;
 
-		VECCOPY(vec, G.vd->viewinv[2]);
+		VECCOPY(vec, norm);
 		VecMulf(vec, factor);
 
 		VecAddf(out, in, vec);
@@ -161,7 +191,7 @@ void applyAxisConstraintVec(TransInfo *t, TransData *td, float in[3], float out[
 		Mat3MulVecfl(t->con.imtx, out);
 		if (!(out[0] == out[1] == out[2] == 0.0f)) {
 			if (getConstraintSpaceDimension(t) == 2) {
-				planeProjection(in, out);
+				planeProjection(t, in, out);
 			}
 			else if (getConstraintSpaceDimension(t) == 1) {
 				float c[3];
@@ -175,7 +205,7 @@ void applyAxisConstraintVec(TransInfo *t, TransData *td, float in[3], float out[
 				else if (t->con.mode & CONAXIS2) {
 					VECCOPY(c, t->con.mtx[2]);
 				}
-				axisProjection(c, in, out);
+				axisProjection(t, c, in, out);
 			}
 		}
 		

source/blender/src/view.c

@@ -174,11 +174,11 @@ void project_short(float *vec, short *adr)	/* clips */
 	Mat4MulVec4fl(G.vd->persmat, vec4);
 
 	if( vec4[3]>BL_NEAR_CLIP ) {	/* 0.001 is the NEAR clipping cutoff for picking */
-		fx= (curarea->winx/2)+(curarea->winx/2)*vec4[0]/vec4[3];
+		fx= (curarea->winx/2)*(1 + vec4[0]/vec4[3]);
 		
 		if( fx>0 && fx<curarea->winx) {
 		
-			fy= (curarea->winy/2)+(curarea->winy/2)*vec4[1]/vec4[3];
+			fy= (curarea->winy/2)*(1 + vec4[1]/vec4[3]);
 			
 			if(fy>0.0 && fy< (float)curarea->winy) {
 				adr[0]= floor(fx); 
@@ -199,11 +199,11 @@ void project_short_noclip(float *vec, short *adr)
 	Mat4MulVec4fl(G.vd->persmat, vec4);
 
 	if( vec4[3]>BL_NEAR_CLIP ) {	/* 0.001 is the NEAR clipping cutoff for picking */
-		fx= (curarea->winx/2)+(curarea->winx/2)*vec4[0]/vec4[3];
+		fx= (curarea->winx/2)*(1 + vec4[0]/vec4[3]);
 		
 		if( fx>-32700 && fx<32700) {
 		
-			fy= (curarea->winy/2)+(curarea->winy/2)*vec4[1]/vec4[3];
+			fy= (curarea->winy/2)*(1 + vec4[1]/vec4[3]);
 			
 			if(fy>-32700.0 && fy<32700.0) {
 				adr[0]= floor(fx);