Nurbs Test Descriptions

19

This chapter describes the Nurbs test programs. The following is defined for each test program:

• Name of the test program
• Test types (See the section "Denizen Test Types" on page 2 for the different test types.)
• Description of the test program
• Attributes tested by the program
• Operators tested by the program
• Output from the test program

· nubs_args

Test Types:	INDEX, SM
Description:	Varies the control points, knot vector, parameter range, and the order of curve. The first loop tests four examples of nonrational B-spline curves, while the final loop tests three examples of rational B-spline curves as the various parameters are varied.

Attributes Tested: XGL_CURVE_CONST_PARAM_SUBDIV_BETWEEN_KNOTS and Table 19-1, Column A at the end of this chapter

Operators Tested: xgl_context_new_frame

Output:· nubs_approx	The nonrational B-splines look like (1) a v-shaped line, (2) a musical note on its side, (3) a portion of a circle, and (4) a tooth with an indented right edge. The rational B-spline curves look like (1) a sleigh with a portion of the top missing, (2) a tooth with an indented right edge plus two rounded curves connected at a single point, and (3) a portion of an ellipse.
Test Types:	INDEX, SM
Description:	Sets XGL_CTX_CURVE_APPROX to various approximation methods in computing the nurbs curves for a quadratic B-spline

Attributes Tested: XGL_CTX_MAX_TESSELLATION

                    XGL_CURVE_UNUSED_BETWEEN_KNOTS
                    and Table 19-1, Column A at the end of this chapter
Operators Tested:   xgl_context_new_frame
                    xgl_nu_bspline_curve
                    xgl_object_set
                    xgl_object_get
Output:             Same curve displayed with different approximations

appears similar to the letter "e" rotated to point to the lower portion of the window raster

· nubs_attr

Test Types:	INDEX, SM
Description:	Tests that line attributes are also applied to nurbs curves using a quadratic B-spline.

Attributes Tested: See Table 19-1, Column B at the end of this chapter

Operators Tested: xgl_context_new_frame

                    xgl_nu_bspline_curve
                    xgl_object_set
Output:             Curve whose appearance looks like an ampersand on its

side that varies dependent on the line pattern and width of the line

· nubs_pttypes

Test Types:	INDEX, SM
Description:	Renders a quadratic spline curve using different point types to ensure the B-spline curves work with different point types. Tries different point types in the following order:
XGL_PT_I2D· nubs_hlhsr
Test Types:	INDEX, SM
Description:	Tests nurbs' hidden line-hidden surface removal. Draws the curve twice, once using a depth that is expected to be overdrawn by the more forward z-valued curve, and once using a depth that produces a more forward curve. Changes the colors for the two curves so that we can expect hidden line-hidden surface removal to display only one color. Checks that only this one color is displayed on the screen.

Attributes Tested: XGL_CURVE_UNUSED_BETWEEN_KNOTS and Table 19-1, Column A at the end of this chapter

Operators Tested: xgl_context_new_frame

Output:.....Curves displayed alternate between three alternatives: (1) a lemon on its side, (2) an ampersand on its side, and (3) the letter "e" rotated to point to the lower left portion of the window raster

· nubs0

Test Types:	RGB, SM
Description:	Varies the control points, knot vector, parameter range, and the order of curve in RGB. The first loop tests four examples of nonrational B-spline curves while the final loop tests three examples of rational B-spline curves, and the various parameters are varied. Same test as nubs_args but using an RGB raster.

Attributes Tested: XGL_CURVE_UNUSED_BETWEEN_KNOTS and Table 19-1, Column A at the end of this chapter

Operators Tested: xgl_context_new_frame

                    xgl_nu_bspline_curve
Output:             The nonrational B-splines look like (1) a v-shaped line, (2)

a musical note on its side, (3) a portion of a circle, and (4) a tooth with an indented right edge plus a small written "s" on its side. The rational B-spline curves look like (1) a sleigh with a portion of the top missing, (2) a tooth with an indented right edge plus two rounded curves connected at a single point, and (3) a portion of an ellipse.

· nubs1

Test Types:	RGB, SM
Description:	Sets XGL_CTX_CURVE_APPROX to various approximation methods in RGB version of nubs_approx

Attributes Tested: XGL_CTX_MAX_TESSELLATION

                    XGL_CURVE_UNUSED_BETWEEN_KNOTS
                    and Table 19-1, Column A at the end of this chapter
Operators Tested:   xgl_context_new_frame
                    xgl_nu_bspline_curve
                    xgl_object_get
                    xgl_object_set
Output:             Same curve displayed with different approximations

appears similar to the letter "e" rotated to point to the lower portion of the window raster

· nubs2

Test Types:	RGB, SM
Description:XGL_PT_I2D· nubs3	Renders a quadratic spline curve using different point types to ensure B-spline curves work with different point types. RGB version of nubs_pttypes. Different point types are tried in the following order:
Test Types:	RGB, SM
Description:	Tests RGB nurbs' hidden line-hidden surface removal. Draws the curve twice, once using a depth that is expected to be overdrawn by the more forward z-valued curve, and once using a depth that produces a more forward curve. Changes the colors for the two curves so that we can expect hidden line-hidden surface removal to display only one color. Checks that only this one color is displayed on the screen. Same as nubs_hlhsr but RGB instead of INDEX.

Attributes Tested: XGL_CURVE_UNUSED_BETWEEN_KNOTS and Table 19-1, Column A at the end of this chapter

Operators Tested: xgl_context_new_frame

                    xgl_nu_bspline_curve
                    xgl_object_set
Output:             Curves displayed alternate between three alternatives: (1)

a lemon on its side, (2) an ampersand on its side, and (3) the letter "e" rotated to point to the lower left portion of the window raster

· nubs4

Test Types:	RGB, SM
Description:	Varies the RGB colors randomly and try settings for XGL_CTX_MAX_TESSELATION from 128 down to 5 in equal decrements of 1 on a quadratic B-spline curve

Attributes Tested: XGL_CTX_MAX_TESSELATION XGL_CURVE_METRIC_VDC and Table 19-1, Column A at the end of this chapter

Operators Tested: xgl_context_new_frame

Output:· nubs5	The curve looks like a cross between a plump "v" seen from an angle and an ampersand on its side.
Test Types:	RGB, SM
Description:	Varies the RGB colors randomly and increases two of the knot values by increments of 0.01 to 0.25 for a quadratic B-spline curve

Attributes Tested: XGL_CURVE_METRIC_VDC and Table 19-1, Column A at the end of this chapter

Operators Tested: xgl_context_new_frame

Output:· gc_nubs_args	Curve looks similar to an ampersand on its side
Test Types:	INDEX, SM
Description:	Varies the control points, knot vector, parameter range, and the order of curve. Then renders the curve into a gcache. The first loop tests four examples of nonrational B-spline curves while the final loop tests three examples of rational B-spline curves as the various parameters are varied. Same test as nubs_args but using a gcache.

Attributes Tested: XGL_GCACHE XGL_CURVE_UNUSED_BETWEEN_KNOTS and Table 19-1, Column A at the end of this chapter

Operators Tested: xgl_object_create

Output:· gc_nubs_pttypes	The nonrational B-splines look like (1) a v-shaped line, (2) musical note on its side, (3) a portion of a circle, and (4) a tooth with an indented right edge plus a small written "s" on its side. The rational B-spline curves look like (1) a sleigh with a portion of the top missing, (2) a tooth with an indented right edge plus two rounded curves connected at a single point, and (3) a portion of an ellipse.
Test Types:	INDEX, SM
Description:XGL_PT_I2D· gc_nubs0	Tests that nurbs can be rendered into a gcache using different point types. Gcache version of nubs_pttypes. Tries different point types in the following order:
Test Types:	RGB, SM
Description:	Varies the RGB control points, knot vector, parameter range, and the order of the curve. Then renders the curve into a gcache. The first loop tests four examples of

nonrational B-spline curves, while the final loop tests three examples of rational B-spline curves, and the various parameters are varied. Same test as nubs_args but using a gcache.

Attributes Tested: XGL_GCACHE

                    XGL_CURVE_UNUSED_BETWEEN_KNOTS
                    and Table 19-1, Column A at the end of this chapter
Operators Tested:   xgl_object_create
                    xgl_gcache_nu_bspline_curve
                    xgl_context_new_frame
                    xgl_context_display_gcache
Output:             The nonrational B-splines look like (1) a v-shaped line, (2)

a musical note on its side, (3) a portion of a circle, and (4) a tooth with an indented right edge plus a small written "s" on its side. The rational B-spline curves look like (1) a sleigh with a portion of the top missing, (2) a tooth with an indented right edge plus two rounded curves connected at a single point, and (3) a portion of an ellipse.

· gc_nubs2

Test Types:	RGB, SM
Description:	Tests that RGB nurbs can be rendered into a gcache using different point types. Gcache RGB version of nubs_pttypes. Tries different point types in the following order:

                    XGL_PT_I2D
                    XGL_PT_I2H
                    XGL_PT_F2D
                    XGL_PT_F2H
                    XGL_PT_F3D
                    XGL_PT_F3H
Attributes Tested:  XGL_CURVE_UNUSED_BETWEEN_KNOTS
                    XGL_GCACHE
                    and Table 19-1, Column A at the end of this chapter
Operators Tested:   xgl_object_create
                    xgl_gcache_nu_bspline_curve
                    xgl_context_new_frame
                    xgl_context_display_gcache
Output:             Curves displayed alternate between a lemon on its side
                    and an ampersand on its side

· nurbs0

Test Types:	RGB, SM
Description:	Tests that non-trimmed surface nurbs can be rendered with various surface parameters. Point type: Xgl_pt_f3d.

Attributes Tested: XGL_3D_CTX_HLHSR_MODE

Operators Tested: xgl_object_create

Output:· nurbs1	A surface with and without edges and isolines.
Test Types:	RGB, SM
Description:	Tests that trimmed surface nurbs can be rendered with various surface parameters. Point type: Xgl_pt_f3h.

Attributes Tested: XGL_3D_CTX_HLHSR_MODE

XGL_HLHSR_Z_BUFFER
XGL_CTX_NEW_FRAME_ACTION
XGL_CTX_NEW_FRAME_CLEAR
XGL_CTX_NEW_FRAME_HLHSR_ACTION
XGL_CTX_LINE_COLOR
XGL_CTX_EDGE_COLOR
XGL_CTX_SURF_FRONT_COLOR
XGL_CTX_SURF_FRONT_FILL_STYLE
XGL_CTX_SURF_EDGE_FLAG

                    XGL_CTX_NURBS_SURF_APPROX
                    XGL_CTX_NURBS_SURF_APPROV_VAL_{UV}
                    XGL_CTX_NURBS_SURF_PARAM_STYLE
                    XGL_CTX_NURBS_SURF_ISO_CURVE_PLACEMENT
                    XGL_CTX_NURBS_SURF_ISO_CURVE_{UV}_NUM
Operators Tested:   xgl_object_create
                    xgl_nurbs_surface
                    xgl_context_new_frame
Output:             A sphere with and without trimming, with and without
                    edges and isolines.

· gc_nurbs0

Test Types:	RGB, SM
Description:	Tests that surface nurbs can be rendered into a gcache using different gcache modes. Gcache modes are:
XGL_GCACHE_NURBS_DYNAMIC· nurb_silo
Test Types:	RGB, CM
Description:	Tests that surface nurbs can draw silhouettes.

Attributes Tested: XGL_3D_CTX_HLHSR_MODE

                    XGL_CTX_NEW_FRAME_ACTION
                    XGL_CTX_NEW_FRAME_CLEAR
                    XGL_CTX_NEW_FRAME_HLHSR_ACTION
                    XGL_CTX_NURBS_SURF_APPROX
                    XGL_CTX_NURBS_SURF_APPROV_VAL_{UV}
                    XGL_CTX_NURBS_SURF_PARAM_STYLE
                    XGL_3D_CTX_SURF_SILHOUETTE_EDGE_FLAG
                    XGL_GCACHE,XGL_GCACHE_NURBS_SURF_MODE
                    XGL_HLHSR_Z_BUFFER
Operators Tested:   xgl_object_create
                    xgl_nurbs_surface
                    xgl_context_new_frame
Output:             Draws a plane with a large bump in it.

· nurb_tiny

Test Types:	RGB, CM
Description:	Tests when nurbs uses a special case for simple nurbs

Attributes Tested: XGL_3D_CTX_HLHSR_MODE

                    XGL_CTX_NEW_FRAME_ACTION
                    XGL_CTX_NEW_FRAME_CLEAR
                    XGL_CTX_NEW_FRAME_HLHSR_ACTION
                    XGL_CTX_NURBS_SURF_APPROX
                    XGL_CTX_NURBS_SURF_APPROV_VAL_{UV}
                    XGL_CTX_NURBS_SURF_PARAM_STYLE
                    XGL_GCACHE
                    XGL_GCACHE_NURBS_SURF_MODE
                    XGL_HLHSR_Z_BUFFER
Operators Tested:   xgl_object_create
                    xgl_gcache_nurbs_surface
                    xgl_context_new_frame
                    xgl_context_display_gcache
Output:             Flat plane on bottom and on top a plane with a bump in it

· nurb_sub

Test Types:	RGB, CM
Description:	Tests that surface nurbs can be subdivided

Attributes Tested: XGL_3D_CTX_HLHSR_MODE

                    XGL_CTX_NEW_FRAME_ACTION
                    XGL_CTX_NEW_FRAME_CLEAR
                    XGL_CTX_NEW_FRAME_HLHSR_ACTION
                    XGL_CTX_NURBS_SURF_APPROX
                    XGL_CTX_NURBS_SURF_APPROV_VAL_{UV}
                    XGL_CTX_NURBS_SURF_PARAM_STYLE
                    XGL_GCACHE
                    XGL_GCACHE_NURBS_SURF_MODE
                    XGL_HLHSR_Z_BUFFER
Operators Tested:   xgl_object_create
                    xgl_gcache_nurbs_surface
                    xgl_context_new_frame
                    xgl_context_display_gcache
Output:             Plane with bump and tessellation outlines on

· nurb_high

Test Types:	RGB, CM
Description:	Tests rendering of high order surfaces

Attributes Tested: XGL_3D_CTX_HLHSR_MODE

                    XGL_CTX_NEW_FRAME_ACTION
                    XGL_CTX_NEW_FRAME_CLEAR
                    XGL_CTX_NEW_FRAME_HLHSR_ACTION
                    XGL_CTX_NURBS_SURF_APPROX
                    XGL_CTX_NURBS_SURF_APPROV_VAL_{UV}
                    XGL_CTX_NURBS_SURF_PARAM_STYLE
                    XGL_GCACHE
                    XGL_GCACHE_NURBS_SURF_MODE
                    XGL_HLHSR_Z_BUFFER
Operators Tested:   xgl_object_create
                    xgl_gcache_nurbs_surface
                    xgl_context_new_frame
                    xgl_context_display_gcache
Output:             Square and error message: Error number di-130: Order is
                    not supported

· nurb_trim1

Test Types:	RGB, CM
Description:	Tests trimming nurbs

Attributes Tested: XGL_3D_CTX_HLHSR_MODE

                    XGL_CTX_NEW_FRAME_ACTION
                    XGL_CTX_NEW_FRAME_CLEAR
                    XGL_CTX_NEW_FRAME_HLHSR_ACTION
                    XGL_GCACHE
                    XGL_GCACHE_NURBS_SURF_MODE
                    XGL_HLHSR_Z_BUFFER
Operators Tested:   xgl_object_create
                    xgl_gcache_nurbs_surface
                    xgl_context_new_frame
                    xgl_context_display_gcache
Output:             Square with curve on the bottom edge

· nurb_trim2

Test Types:	RGB, CM
Description:	Tests trimming nurbs

Attributes Tested: XGL_3D_CTX_HLHSR_MODE

                    XGL_CTX_NEW_FRAME_ACTION
                    XGL_CTX_NEW_FRAME_CLEAR
                    XGL_CTX_NEW_FRAME_HLHSR_ACTION
                    XGL_GCACHE
                    XGL_GCACHE_NURBS_SURF_MODE
                    XGL_HLHSR_Z_BUFFER
Operators Tested:   xgl_object_create
                    xgl_gcache_nurbs_surface
                    xgl_context_new_frame
                    xgl_context_display_gcache
Output:             Square with curve on the left edge

· nurb_trim3

Test Types:	RGB, CM
Description:	Tests trimming nurbs

Attributes Tested: XGL_3D_CTX_HLHSR_MODE

                    XGL_CTX_NEW_FRAME_ACTION
                    XGL_CTX_NEW_FRAME_CLEAR
                    XGL_CTX_NEW_FRAME_HLHSR_ACTION
                    XGL_GCACHE
                    XGL_GCACHE_NURBS_SURF_MODE
                    XGL_HLHSR_Z_BUFFER
Operators Tested:   xgl_object_create
                    xgl_gcache_nurbs_surface
                    xgl_context_new_frame
                    xgl_context_display_gcache
Output:             Curves on top and bottom edge

· nurb_trim4

Test Types:	RGB, CM
Description:	Tests trimming nurbs

Attributes Tested: XGL_3D_CTX_HLHSR_MODE

                    XGL_CTX_NEW_FRAME_ACTION
                    XGL_CTX_NEW_FRAME_CLEAR
                    XGL_CTX_NEW_FRAME_HLHSR_ACTION
                    XGL_GCACHE
                    XGL_GCACHE_NURBS_SURF_MODE
                    XGL_HLHSR_Z_BUFFER
Operators Tested:   xgl_object_create
                    xgl_gcache_nurbs_surface
                    xgl_context_new_frame
                    xgl_context_display_gcache
Output:             Square with symmetric curve cut in the middle

Table 19-1

Column A	Column B
XGL_3D_CTX_HLHSR_MODE	XGL_3D_CTX_HLHSR_MODE
XGL_CTX_LINE_COLOR	XGL_CTX_LINE_ALT_COLOR
XGL_CTX_NEW_FRAME_ACTION	XGL_CTX_LINE_COLOR
XGL_CTX_NEW_FRAME_CLEAR	XGL_CTX_LINE_PATTERN
XGL_CTX_NEW_FRAME_HLHSR_ ACTION	XGL_CTX_LINE_STYLE
XGL_CTX_NURBS_CURVE_APPROX	XGL_CTX_LINE_WIDTH_SCALE_ FACTOR
XGL_CTX_NURBS_CURVE_APPROX_VAL	XGL_CTX_MAX_TESSELLATION
XGL_HLHSR_Z_BUFFER	XGL_CTX_NEW_FRAME_ACTION XGL_CTX_NEW_FRAME_CLEAR XGL_CTX_NEW_FRAME_HLHSR_ ACTION XGL_CTX_NURBS_CURVE_APPROX XGL_CTX_NURBS_CURVE_APPROX_VAL XGL_CURVE_METRIC_WC XGL_HLHSR_Z_BUFFER XGL_LINE_ALT_PATTERNED XGL_LINE_SOLID