C Library Functions - patch (3)
NAME
patch(3f) - [M_draw:PATCH] Draws a patch in the current basis, according to the geometry matrices gx, gy, and gz. (LICENSE:PD)
CONTENTS
Synopsis
Description
Examples
SYNOPSIS
subroutine patch(gx, gy, gz)
real,intent(in) :: gx(4,4), gy(4,4), gz(4,4)
DESCRIPTION
Draws a patch in the current basis, according to the geometry matrices gx, gy, and gz.
EXAMPLES
Sample program:
program demo_patch ! Draws patches of various bases ! use M_draw implicit none ! character(len=20) :: dev integer :: ios integer :: i integer :: idum ! ! patch basis types ! real bezier(4,4), cardinal(4, 4), bspline(4, 4) real power(4, 4) real x1(4, 4), y1(4, 4), z1(4, 4) real x2(4, 4), y2(4, 4), z2(4, 4) ! character(len=50) :: labels(4) ! real basis(64) equivalence (basis(1), bezier(1, 1)) equivalence (basis(17), cardinal(1, 1)) equivalence (basis(33), bspline(1, 1)) equivalence (basis(49), power(1, 1)) ! data bezier/ & & -1.0, 3.0, -3.0, 1.0, & & 3.0, -6.0, 3.0, 0.0, & & -3.0, 3.0, 0.0, 0.0, & & 1.0, 0.0, 0.0, 0.0/ ! data cardinal/ & & -0.5, 1.5, -1.5, 0.5, & & 1.0, -2.5, 2.0, -0.5, & & -0.5, 0.0, 0.5, 0.0, & & 0.0, 1.0, 0.0, 0.0/ ! data bspline/ & & -0.166666, 0.5, -0.5, 0.166666, & & 0.5, -1.0, 0.5, 0.0, & & -0.5, 0.0, 0.5, 0.0, & & 0.166666, 0.666666, 0.166666, 0.0 / ! data power/ & & 1.0, 0.0, 0.0, 0.0, & & 0.0, 1.0, 0.0, 0.0, & & 0.0, 0.0, 1.0, 0.0, & & 0.0, 0.0, 0.0, 1.0/ ! data x1 / & & 0.0, 0.2588, 0.5, 0.7071, & & 0.0, 0.51764, 1.0, 1.4142, & & 0.0, 0.51764, 1.0, 1.4142, & & 0.0, 0.2588, 0.5, 0.7071/ ! data y1 / & & 1.0, 0.966, 0.866, 0.7071, & & 2.0, 1.9318, 1.732, 1.4142, & & 2.0, 1.9318, 1.732, 1.4142, & & 1.0, 0.966, 0.866, 0.7071/ ! data z1 / & & 1.0, 1.0, 1.0, 1.0, & & 1.0, 1.0, 1.0, 1.0, & & 0.0, 0.0, 0.0, 0.0, & & 0.0, 0.0, 0.0, 0.0/ ! data x2 / & & 0.7071, 0.8660, 0.9660, 1.0, & & 1.4142, 1.7320, 1.932, 2.0, & & 1.4142, 1.7320, 1.932, 2.0, & & 0.7071, 0.8660, 0.9660, 1.0/ ! data y2 / & & 0.7071, 0.5, 0.2588, 0.0, & & 1.4142, 1.0, 0.5176, 0.0, & & 1.4142, 1.0, 0.5176, 0.0, & & 0.7071, 0.5, 0.2588, 0.0/ ! data z2 / & & 1.0, 1.0, 1.0, 1.0, & & 1.0, 1.0, 1.0, 1.0, & & 0.0, 0.0, 0.0, 0.0, & & 0.0, 0.0, 0.0, 0.0/ ! data labels / & & ’Bezier Patch(es)’, & & ’Cardinal Patch(es)’, & & ’B-Spline Patch(es)’, & & ’’’Power’’ Patch(es)’ / ! ! demonstrate patches ! write (*,*)’Enter device:’ read(*,’(a)’,iostat=ios) dev if(ios.ne.0)dev=’ ’ ! call prefsize(1000,1000) call vinit(dev) ! call vsetflush(.true.) ! call color(D_BLACK) call clear() ! ! Set up two viewports (They actually overlap) ! call viewport(-1.0, 0.3, -1.0, 0.3) call ortho(-2.0, 5.0, -2.0, 5.0, -2.0, 5.0) call lookat(0.0, 0.0, 0.0, -3.0, 2.0, -4.0, 0.0) ! ! Save it ! call pushviewport() call pushmatrix() ! call viewport(-0.3, 1.0, -0.3, 1.0) call ortho(-2.0, 5.0, -2.0, 5.0, -2.0, 5.0) call lookat(0.0, 0.0, 0.0, 3.0, 2.0, -4.0, 0.0) ! call textsize(0.4, 0.4) ! ! patchcurves provides a number of curves in the t and u ! directions. patchprecision gives the minimum number of line ! segments making up the curves in the t and u directions. The ! actual number of linesegments in t or u is equal to the closest ! integer multiple of the number of curves, > nsegs, in t or u, ! greater than or equal to the number set by patchprecision in u or ! t. eg. curves in t will be made up of 21 line segments so that we ! can match up the 7 curves in u; curves in u will have 24 as 4 by 5 ! gives 20. ! call patchcurves(4, 7) call patchprecision(20, 20) ! do 10 i = 0, 3 ! call axes() ! ! patchbasis sets the basis matrices for the t and u ! functions ! ! call patchbasis(basis(i*16 + 1), basis(i*16 + 1)) ! ! Draw with viewport 2 ! call move(0.0, 4.0, 0.0) call drawstr(labels(i+1)) ! ! Now draw the patches according to the geometry matrices in ! x1, y1, and z1, x2, y2, z2. ! call drawhull(x1, y1, z1) call patch(x1, y1, z1) ! call drawhull(x2, y2, z2) call patch(x2, y2, z2) ! ! Now with viewport 1 ! call popviewport() call popmatrix() ! call axes() ! call move(0.0, 4.0, 0.0) call drawstr(labels(i + 1)) ! ! now draw the patches according to the geometry matrices in ! x1, y1, and z1, x2, y2, z2. ! call drawhull(x1, y1, z1) call patch(x1, y1, z1) ! call drawhull(x2, y2, z2) call patch(x2, y2, z2) ! idum=getkey() ! ! Save viewport 1 again and reset to viewport 2 ! call pushviewport() call pushmatrix() ! call viewport(-0.3, 1.0, -0.3, 1.0) call ortho(-1.5, 5.0, -1.5, 5.0, -1.5, 5.0) call lookat(0.0, 0.0, 0.0, 3.0, 2.0, -4.0, 0.0) ! call color(D_BLACK) call clear() 10 continue ! call vexit() ! contains ! subroutine drawhull(x, y, z) implicit none ! real x(4,4), y(4,4), z(4,4) integer :: i integer :: j ! call color(D_MAGENTA) do i = 1,4 call move(x(i,1), y(i,1), z(i,1)) do j = 1,4 call draw(x(i,j), y(i,j), z(i,j)) enddo enddo ! do i = 1,4 call move(x(1,i), y(1,i), z(1,i)) do j = 1,4 call draw(x(j,i), y(j,i), z(j,i)) enddo enddo ! call color(D_GREEN) end subroutine drawhull ! subroutine axes() ! ! draw the axes ! call color(D_BLUE) call move(0.0, 0.0, 0.0) call draw(4.0, 0.0, 0.0)call move(0.0, 0.0, 0.0) call draw(0.0, 4.0, 0.0)
call move(0.0, 0.0, 0.0) call draw(0.0, 0.0, 4.0) ! end subroutine axes ! end program demo_patch
| Nemo Release 3.1 | patch (3) | February 23, 2025 |
