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/* $Id: scissor.c,v 1.2 1996/09/15 14:18:37 brianp Exp $ */
/*
* Mesa 3-D graphics library
* Version: 2.0
* Copyright (C) 1995-1996 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 1.2 1996/09/15 14:18:37 brianp
* now use GLframebuffer and GLvisual
*
* Revision 1.1 1996/09/13 01:38:16 brianp
* Initial revision
*
*/
#include "context.h"
#include "macros.h"
#include "dlist.h"
#include "scissor.h"
#include "types.h"
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 {
GLuint i;
/* TODO: this could be better: */
for (i=0;i<n;i++,x++) {
if (x<ctx->Buffer->Xmin || x>ctx->Buffer->Xmax)
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.