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/* $Id: scissor.c,v 1.4 1997/05/28 03:26:29 brianp Exp $ */ /* * Mesa 3-D graphics library * Version: 2.3 * Copyright (C) 1995-1997 Brian Paul * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* * $Log: scissor.c,v $ * Revision 1.4 1997/05/28 03:26:29 brianp * added precompiled header (PCH) support * * Revision 1.3 1997/05/17 03:17:50 brianp * faster gl_scissor_span() from Mats Lofkvist * * Revision 1.2 1996/09/15 14:18:37 brianp * now use GLframebuffer and GLvisual * * Revision 1.1 1996/09/13 01:38:16 brianp * Initial revision * */ #ifdef PCH #include "all.h" #else #include "context.h" #include "macros.h" #include "dlist.h" #include "scissor.h" #include "types.h" #endif void gl_Scissor( GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height ) { if (width<0 || height<0) { gl_error( ctx, GL_INVALID_VALUE, "glScissor" ); return; } if (INSIDE_BEGIN_END(ctx)) { gl_error( ctx, GL_INVALID_OPERATION, "glBegin" ); return; } ctx->Scissor.X = x; ctx->Scissor.Y = y; ctx->Scissor.Width = width; ctx->Scissor.Height = height; ctx->NewState |= NEW_ALL; /* TODO: this is overkill */ } /* * Apply the scissor test to a span of pixels. * Return: 0 = all pixels in the span are outside the scissor box. * 1 = one or more pixels passed the scissor test. */ GLint gl_scissor_span( GLcontext *ctx, GLuint n, GLint x, GLint y, GLubyte mask[] ) { /* first check if whole span is outside the scissor box */ if (y<ctx->Buffer->Ymin || y>ctx->Buffer->Ymax || x>ctx->Buffer->Xmax || x+(GLint)n-1<ctx->Buffer->Xmin) { return 0; } else { GLint i; GLint xMin = ctx->Buffer->Xmin; GLint xMax = ctx->Buffer->Xmax; for (i=0; x+i < xMin; i++) { mask[i] = 0; } for (i=(GLint)n-1; x+i > xMax; i--) { mask[i] = 0; } return 1; } } /* * Apply the scissor test to an array of pixels. */ GLuint gl_scissor_pixels( GLcontext *ctx, GLuint n, const GLint x[], const GLint y[], GLubyte mask[] ) { GLint xmin = ctx->Buffer->Xmin; GLint xmax = ctx->Buffer->Xmax; GLint ymin = ctx->Buffer->Ymin; GLint ymax = ctx->Buffer->Ymax; GLuint i; for (i=0;i<n;i++) { mask[i] &= (x[i]>=xmin) & (x[i]<=xmax) & (y[i]>=ymin) & (y[i]<=ymax); } return 1; }
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.