ReactOS  0.4.14-dev-614-gbfd8a84
scissor.c
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1 /* $Id: scissor.c,v 1.6 1997/11/25 03:38:58 brianp Exp $ */
2 
3 /*
4  * Mesa 3-D graphics library
5  * Version: 2.5
6  * Copyright (C) 1995-1997 Brian Paul
7  *
8  * This library is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Library General Public
10  * License as published by the Free Software Foundation; either
11  * version 2 of the License, or (at your option) any later version.
12  *
13  * This library is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Library General Public License for more details.
17  *
18  * You should have received a copy of the GNU Library General Public
19  * License along with this library; if not, write to the Free
20  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21  */
22 
23 
24 /*
25  * $Log: scissor.c,v $
26  * Revision 1.6 1997/11/25 03:38:58 brianp
27  * small optimization to gl_Scissor() (Daryll Strauss)
28  *
29  * Revision 1.5 1997/07/24 01:21:56 brianp
30  * changed precompiled header symbol from PCH to PC_HEADER
31  *
32  * Revision 1.4 1997/05/28 03:26:29 brianp
33  * added precompiled header (PCH) support
34  *
35  * Revision 1.3 1997/05/17 03:17:50 brianp
36  * faster gl_scissor_span() from Mats Lofkvist
37  *
38  * Revision 1.2 1996/09/15 14:18:37 brianp
39  * now use GLframebuffer and GLvisual
40  *
41  * Revision 1.1 1996/09/13 01:38:16 brianp
42  * Initial revision
43  *
44  */
45 
46 
47 #ifdef PC_HEADER
48 #include "all.h"
49 #else
50 #include "context.h"
51 #include "macros.h"
52 #include "dlist.h"
53 #include "scissor.h"
54 #include "types.h"
55 #endif
56 
57 
58 void gl_Scissor( GLcontext *ctx,
60 {
61  if (width<0 || height<0) {
62  gl_error( ctx, GL_INVALID_VALUE, "glScissor" );
63  return;
64  }
65  if (INSIDE_BEGIN_END(ctx)) {
66  gl_error( ctx, GL_INVALID_OPERATION, "glBegin" );
67  return;
68  }
69 
70  if (x!=ctx->Scissor.X || y!=ctx->Scissor.Y ||
71  width!=ctx->Scissor.Width || height!=ctx->Scissor.Height) {
72  ctx->Scissor.X = x;
73  ctx->Scissor.Y = y;
74  ctx->Scissor.Width = width;
75  ctx->Scissor.Height = height;
76  ctx->NewState |= NEW_ALL; /* TODO: this is overkill */
77  }
78 }
79 
80 
81 
82 /*
83  * Apply the scissor test to a span of pixels.
84  * Return: 0 = all pixels in the span are outside the scissor box.
85  * 1 = one or more pixels passed the scissor test.
86  */
88  GLuint n, GLint x, GLint y, GLubyte mask[] )
89 {
90  /* first check if whole span is outside the scissor box */
91  if (y<ctx->Buffer->Ymin || y>ctx->Buffer->Ymax
92  || x>ctx->Buffer->Xmax || x+(GLint)n-1<ctx->Buffer->Xmin) {
93  return 0;
94  }
95  else {
96  GLint i;
97  GLint xMin = ctx->Buffer->Xmin;
98  GLint xMax = ctx->Buffer->Xmax;
99  for (i=0; x+i < xMin; i++) {
100  mask[i] = 0;
101  }
102  for (i=(GLint)n-1; x+i > xMax; i--) {
103  mask[i] = 0;
104  }
105 
106  return 1;
107  }
108 }
109 
110 
111 
112 
113 /*
114  * Apply the scissor test to an array of pixels.
115  */
117  GLuint n, const GLint x[], const GLint y[],
118  GLubyte mask[] )
119 {
120  GLint xmin = ctx->Buffer->Xmin;
121  GLint xmax = ctx->Buffer->Xmax;
122  GLint ymin = ctx->Buffer->Ymin;
123  GLint ymax = ctx->Buffer->Ymax;
124  GLuint i;
125 
126  for (i=0;i<n;i++) {
127  mask[i] &= (x[i]>=xmin) & (x[i]<=xmax) & (y[i]>=ymin) & (y[i]<=ymax);
128  }
129 
130  return 1;
131 }
132 
GLint GLint GLsizei width
Definition: gl.h:1546
GLframebuffer * Buffer
Definition: types.h:1273
GLuint NewState
Definition: types.h:1355
unsigned char GLubyte
Definition: gl.h:157
GLint Ymin
Definition: types.h:1195
GLdouble n
Definition: glext.h:7729
GLint GLint GLint GLint GLint x
Definition: gl.h:1548
#define INSIDE_BEGIN_END(CTX)
Definition: macros.h:135
GLsizei GLenum const GLvoid GLsizei GLenum GLbyte GLbyte GLbyte GLdouble GLdouble GLdouble GLfloat GLfloat GLfloat GLint GLint GLint GLshort GLshort GLshort GLubyte GLubyte GLubyte GLuint GLuint GLuint GLushort GLushort GLushort GLbyte GLbyte GLbyte GLbyte GLdouble GLdouble GLdouble GLdouble GLfloat GLfloat GLfloat GLfloat GLint GLint GLint GLint GLshort GLshort GLshort GLshort GLubyte GLubyte GLubyte GLubyte GLuint GLuint GLuint GLuint GLushort GLushort GLushort GLushort GLboolean const GLdouble const GLfloat const GLint const GLshort const GLbyte const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLdouble const GLfloat const GLfloat const GLint const GLint const GLshort const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort const GLdouble const GLfloat const GLint const GLshort GLenum GLenum GLenum GLfloat GLenum GLint GLenum GLenum GLenum GLfloat GLenum GLenum GLint GLenum GLfloat GLenum GLint GLint GLushort GLenum GLenum GLfloat GLenum GLenum GLint GLfloat const GLubyte GLenum GLenum GLenum const GLfloat GLenum GLenum const GLint GLenum GLint GLint GLsizei GLsizei GLint GLenum GLenum const GLvoid GLenum GLenum const GLfloat GLenum GLenum const GLint GLenum GLenum const GLdouble GLenum GLenum const GLfloat GLenum GLenum const GLint GLsizei GLuint GLfloat GLuint GLbitfield GLfloat GLint GLuint GLboolean GLenum GLfloat GLenum GLbitfield GLenum GLfloat GLfloat GLint GLint const GLfloat GLenum GLfloat GLfloat GLint GLint GLfloat GLfloat GLint GLint const GLfloat GLint GLfloat GLfloat GLint GLfloat GLfloat GLint GLfloat GLfloat const GLdouble const GLfloat const GLdouble const GLfloat GLint i
Definition: glfuncs.h:248
GLenum GLint GLuint mask
Definition: glext.h:6028
int GLsizei
Definition: gl.h:160
GLint gl_scissor_span(GLcontext *ctx, GLuint n, GLint x, GLint y, GLubyte mask[])
Definition: scissor.c:87
Definition: bufpool.h:45
GLint Xmin
Definition: types.h:1195
struct gl_scissor_attrib Scissor
Definition: types.h:1332
#define NEW_ALL
Definition: types.h:1236
GLuint gl_scissor_pixels(GLcontext *ctx, GLuint n, const GLint x[], const GLint y[], GLubyte mask[])
Definition: scissor.c:116
#define GL_INVALID_VALUE
Definition: gl.h:695
#define GL_INVALID_OPERATION
Definition: gl.h:696
GLint GLint GLsizei GLsizei height
Definition: gl.h:1546
void gl_error(GLcontext *ctx, GLenum error, const char *s)
Definition: context.c:1421
GLint Ymax
Definition: types.h:1195
unsigned int GLuint
Definition: gl.h:159
GLint GLint GLint GLint GLint GLint y
Definition: gl.h:1548
int GLint
Definition: gl.h:156
GLint Xmax
Definition: types.h:1195
void gl_Scissor(GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height)
Definition: scissor.c:58