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/*

 * Mesa 3-D graphics library

 *

 * Copyright (C) 2009  VMware, Inc.  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

 * THE AUTHORS OR COPYRIGHT HOLDERS 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.

 */

/**

 * \file viewport.c

 * glViewport and glDepthRange functions.

 */

#include "context.h"

#include "macros.h"

#include "mtypes.h"

#include "viewport.h"

/**

 * Set the viewport.

 * \sa Called via glViewport() or display list execution.

 *

 * Flushes the vertices and calls _mesa_set_viewport() with the given

 * parameters.

 */

void GLAPIENTRY

_mesa_Viewport(GLint x, GLint y, GLsizei width, GLsizei height)

{

   GET_CURRENT_CONTEXT(ctx);

   FLUSH_VERTICES(ctx, 0);

   _mesa_set_viewport(ctx, x, y, width, height);

}

/**

 * Set new viewport parameters and update derived state (the _WindowMap

 * matrix).  Usually called from _mesa_Viewport().

 *

 * \param ctx GL context.

 * \param x, y coordinates of the lower left corner of the viewport rectangle.

 * \param width width of the viewport rectangle.

 * \param height height of the viewport rectangle.

 */

void

_mesa_set_viewport(struct gl_context *ctx, GLint x, GLint y,

                    GLsizei width, GLsizei height)

{

   if (MESA_VERBOSE & VERBOSE_API)

      _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);

   if (width < 0 || height < 0) {

      _mesa_error(ctx,  GL_INVALID_VALUE,

                   "glViewport(%d, %d, %d, %d)", x, y, width, height);

      return;

   }

   /* clamp width and height to the implementation dependent range */

   width  = MIN2(width, (GLsizei) ctx->Const.MaxViewportWidth);

   height = MIN2(height, (GLsizei) ctx->Const.MaxViewportHeight);

   ctx->Viewport.X = x;

   ctx->Viewport.Width = width;

   ctx->Viewport.Y = y;

   ctx->Viewport.Height = height;

   ctx->NewState |= _NEW_VIEWPORT;

#if 1

   /* XXX remove this someday.  Currently the DRI drivers rely on

    * the WindowMap matrix being up to date in the driver's Viewport

    * and DepthRange functions.

    */

   _math_matrix_viewport(&ctx->Viewport._WindowMap,

                         ctx->Viewport.X, ctx->Viewport.Y,

                         ctx->Viewport.Width, ctx->Viewport.Height,

                         ctx->Viewport.Near, ctx->Viewport.Far,

                         ctx->DrawBuffer->_DepthMaxF);

#endif

   if (ctx->Driver.Viewport) {

      /* Many drivers will use this call to check for window size changes

       * and reallocate the z/stencil/accum/etc buffers if needed.

       */

      ctx->Driver.Viewport(ctx, x, y, width, height);

   }

}

/**

 * Called by glDepthRange

 *

 * \param nearval  specifies the Z buffer value which should correspond to

 *                 the near clip plane

 * \param farval  specifies the Z buffer value which should correspond to

 *                the far clip plane

 */

void GLAPIENTRY

_mesa_DepthRange(GLclampd nearval, GLclampd farval)

{

   GET_CURRENT_CONTEXT(ctx);

   FLUSH_VERTICES(ctx, 0);

   if (MESA_VERBOSE&VERBOSE_API)

      _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);

   if (ctx->Viewport.Near == nearval &&

       ctx->Viewport.Far == farval)

      return;

   ctx->Viewport.Near = (GLfloat) CLAMP(nearval, 0.0, 1.0);

   ctx->Viewport.Far = (GLfloat) CLAMP(farval, 0.0, 1.0);

   ctx->NewState |= _NEW_VIEWPORT;

#if 1

   /* XXX remove this someday.  Currently the DRI drivers rely on

    * the WindowMap matrix being up to date in the driver's Viewport

    * and DepthRange functions.

    */

   _math_matrix_viewport(&ctx->Viewport._WindowMap,

                         ctx->Viewport.X, ctx->Viewport.Y,

                         ctx->Viewport.Width, ctx->Viewport.Height,

                         ctx->Viewport.Near, ctx->Viewport.Far,

                         ctx->DrawBuffer->_DepthMaxF);

#endif

   if (ctx->Driver.DepthRange) {

      ctx->Driver.DepthRange(ctx, nearval, farval);

   }

}

void GLAPIENTRY

_mesa_DepthRangef(GLclampf nearval, GLclampf farval)

{

   _mesa_DepthRange(nearval, farval);

}

/**

 * Initialize the context viewport attribute group.

 * \param ctx  the GL context.

 */

void _mesa_init_viewport(struct gl_context *ctx)

{

   GLfloat depthMax = 65535.0F; /* sorf of arbitrary */

   /* Viewport group */

   ctx->Viewport.X = 0;

   ctx->Viewport.Y = 0;

   ctx->Viewport.Width = 0;

   ctx->Viewport.Height = 0;

   ctx->Viewport.Near = 0.0;

   ctx->Viewport.Far = 1.0;

   _math_matrix_ctr(&ctx->Viewport._WindowMap);

   _math_matrix_viewport(&ctx->Viewport._WindowMap, 0, 0, 0, 0,

                         0.0F, 1.0F, depthMax);

}

/**

 * Free the context viewport attribute group data.

 * \param ctx  the GL context.

 */

void _mesa_free_viewport_data(struct gl_context *ctx)

{

   _math_matrix_dtr(&ctx->Viewport._WindowMap);

}