- initial import

git-svn-id: http://moon:8086/svn/mips@1 a8ebac50-d88d-4704-bea3-6648445a41b3
2014-07-20 15:01:37 +00:00
commit 26291bca3d
1549 changed files with 3997969 additions and 0 deletions
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+#include <math.h>
+#include "ri.h"
+#include "camset.h"
+
+#define min(a,b) ((a)<(b)?(a):(b))
+#define PI		3.1415926535897932384626433832795
+
+
+/* PlaceCamera(): establish a viewpoint, viewing direction and orientation
+ *    for a scene. This routine must be called before RiWorldBegin().
+ *    position: a point giving the camera position
+ *    direction: a point giving the camera direction relative to position
+ *    roll: an optional rotation of the camera about its direction axis
+ */
+void PlaceCamera(RtPoint position, RtPoint direction, float roll)
+{
+	RiIdentity();                 /* Initialize the camera transformation */
+	if (roll != 0.0)
+		RiRotate(-roll, 0.0, 0.0, 1.0);
+	AimZ(direction);
+	RiTranslate(-position[0], -position[1], -position[2]);
+}
+
+void AimZ(RtPoint direction)
+{
+	double xzlen, yzlen, yrot, xrot;
+
+	if (direction[0]==0 && direction[1]==0 && direction[2]==0)
+		return;
+	/*
+	* The initial rotation about the y axis is given by the projection of
+	* the direction vector onto the x,z plane: the x and z components
+	* of the direction.
+	*/
+
+	xzlen = sqrt(direction[0]*direction[0]+direction[2]*direction[2]);
+	if (xzlen == 0)
+		yrot = (direction[1] < 0) ? 180 : 0;
+	else
+		yrot = 180*acos(direction[2]/xzlen)/PI;
+
+	/*
+	* The second rotation, about the x axis, is given by the projection on
+	* the y,z plane of the y-rotated direction vector: the original y
+	* component, and the rotated x,z vector from above.
+	*/
+
+	yzlen = sqrt(direction[1]*direction[1]+xzlen*xzlen);
+	xrot = 180*acos(xzlen/yzlen)/PI;       /* yzlen should never be 0 */
+
+	if (xrot != 0.0)
+	{
+		if (direction[1] > 0)
+			RiRotate(xrot, 1.0, 0.0, 0.0);
+		else
+			RiRotate(-xrot, 1.0, 0.0, 0.0);
+	}
+
+	/* The last rotation declared gets performed first */
+	if (yrot != 0.0)
+	{
+		if (direction[0] > 0)
+			RiRotate(-yrot, 0.0, 1.0, 0.0);
+		else
+			RiRotate(yrot, 0.0, 1.0, 0.0);
+	}
+}
+
+/* FrameCamera(): give physical parameters for a camera.
+   Parameters:
+    focallength: the "camera's" focal length.
+    framewidth:  the width of the film frame
+    frameheight: the height of the film frame
+*/
+void FrameCamera(float focallength, float framewidth, float frameheight)
+{
+	RtFloat normwidth, normheight;
+
+	/* Focal length of 0 is taken to be an orthographic projection */
+	if (focallength != 0.0)
+	{
+		RiProjection("perspective", RI_NULL);
+		normwidth = (framewidth*.5)/focallength;
+		normheight = (frameheight*.5)/focallength;
+	}
+	else
+	{
+		RiProjection("orthographic", RI_NULL);
+		normwidth = framewidth*.5;
+		normheight = frameheight*.5;
+	}
+
+	RiScreenWindow(-normwidth, normwidth, -normheight, normheight);
+}
+
+/* FrameCamera2(): give physical parameters for a camera.
+ * Parameters:
+ *    focallength: controls the width of the camera's field of view.
+ *    framewidth: the width of the film image
+ *    frameheight: the height of the film image*/
+void FrameCamera2(float focallength, float framewidth, float frameheight)
+{
+	RtFloat fov;
+
+	/* A nonzero focal length is taken to be a "normal" lens */
+	if(focallength != 0.0)
+	{
+		fov = 2 * atan((min(framewidth,frameheight)*.5)/focallength) * 180.0/3.14159;
+		RiProjection("perspective", RI_FOV, (RtPointer)&fov, RI_NULL);
+	}
+	else
+	{
+		RiProjection("orthographic", RI_NULL);
+	}
+
+	RiFrameAspectRatio((RtFloat)(framewidth/frameheight));
+}