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/*
* Mesa 3-D graphics library
* Version: 3.3
*
* Copyright (C) 1999 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifdef PC_HEADER
#include "all.h"
#else
#include "glheader.h"
#include "context.h"
#include "macros.h"
#include "scissor.h"
#include "types.h"
#endif
void
_mesa_Scissor( GLint x, GLint y, GLsizei width, GLsizei height )
{
GET_CURRENT_CONTEXT(ctx);
ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glScissor");
if (width < 0 || height < 0) {
gl_error( ctx, GL_INVALID_VALUE, "glScissor" );
return;
}
if (MESA_VERBOSE & VERBOSE_API)
fprintf(stderr, "glScissor %d %d %d %d\n", x, y, width, height);
if (x != ctx->Scissor.X ||
y != ctx->Scissor.Y ||
width != ctx->Scissor.Width ||
height != ctx->Scissor.Height) {
ctx->Scissor.X = x;
ctx->Scissor.Y = y;
ctx->Scissor.Width = width;
ctx->Scissor.Height = height;
ctx->NewState |= NEW_RASTER_OPS;
}
if (ctx->Driver.Scissor)
ctx->Driver.Scissor( ctx, x, y, width, height );
}
/*
* 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->DrawBuffer->Ymin
|| y > ctx->DrawBuffer->Ymax
|| x > ctx->DrawBuffer->Xmax
|| x + (GLint) n - 1 < ctx->DrawBuffer->Xmin) {
return 0;
}
else {
const GLint xMin = ctx->DrawBuffer->Xmin;
const GLint xMax = ctx->DrawBuffer->Xmax;
GLint i;
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[] )
{
const GLint xmin = ctx->DrawBuffer->Xmin;
const GLint xmax = ctx->DrawBuffer->Xmax;
const GLint ymin = ctx->DrawBuffer->Ymin;
const GLint ymax = ctx->DrawBuffer->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;
}
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