src/mesa/main/viewport.c - platform/external/mesa3d - Git at Google

 /*
  * 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 "enums.h"
 #include "macros.h"
 #include "mtypes.h"
 #include "viewport.h"

 static void
 set_viewport_no_notify(struct gl_context *ctx, unsigned idx,
                        GLfloat x, GLfloat y,
                        GLfloat width, GLfloat height)
 {
    /* clamp width and height to the implementation dependent range */
    width  = MIN2(width, (GLfloat) ctx->Const.MaxViewportWidth);
    height = MIN2(height, (GLfloat) ctx->Const.MaxViewportHeight);

    /* The GL_ARB_viewport_array spec says:
     *
     *     "The location of the viewport's bottom-left corner, given by (x,y),
     *     are clamped to be within the implementation-dependent viewport
     *     bounds range.  The viewport bounds range [min, max] tuple may be
     *     determined by calling GetFloatv with the symbolic constant
     *     VIEWPORT_BOUNDS_RANGE (see section 6.1)."
     */
    if (ctx->Extensions.ARB_viewport_array ||
        (ctx->Extensions.OES_viewport_array &&
         _mesa_is_gles31(ctx))) {
       x = CLAMP(x,
                 ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
       y = CLAMP(y,
                 ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
    }

    if (ctx->ViewportArray[idx].X == x &&
        ctx->ViewportArray[idx].Width == width &&
        ctx->ViewportArray[idx].Y == y &&
        ctx->ViewportArray[idx].Height == height)
       return;

    ctx->ViewportArray[idx].X = x;
    ctx->ViewportArray[idx].Width = width;
    ctx->ViewportArray[idx].Y = y;
    ctx->ViewportArray[idx].Height = height;
    ctx->NewState |= _NEW_VIEWPORT;
 }

 struct gl_viewport_inputs {
    GLfloat X, Y;                /**< position */
    GLfloat Width, Height;       /**< size */
 };

 struct gl_depthrange_inputs {
    GLdouble Near, Far;          /**< Depth buffer range */
 };

 /**
  * 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)
 {
    unsigned i;
    GET_CURRENT_CONTEXT(ctx);
    FLUSH_VERTICES(ctx, 0);

    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;
    }

    /* The GL_ARB_viewport_array spec says:
     *
     *     "Viewport sets the parameters for all viewports to the same values
     *     and is equivalent (assuming no errors are generated) to:
     *
     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
     *         ViewportIndexedf(i, 1, (float)x, (float)y, (float)w, (float)h);"
     *
     * Set all of the viewports supported by the implementation, but only
     * signal the driver once at the end.
     */
    for (i = 0; i < ctx->Const.MaxViewports; i++)
       set_viewport_no_notify(ctx, i, x, y, width, height);

    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);
    }
 }


 /**
  * Set new viewport parameters and update derived state.
  * Usually called from _mesa_Viewport().
  *
  * \param ctx GL context.
  * \param idx    Index of the viewport to be updated.
  * \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, unsigned idx, GLfloat x, GLfloat y,
                     GLfloat width, GLfloat height)
 {
    set_viewport_no_notify(ctx, idx, x, y, width, height);

    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);
    }
 }

 void GLAPIENTRY
 _mesa_ViewportArrayv(GLuint first, GLsizei count, const GLfloat *v)
 {
    int i;
    const struct gl_viewport_inputs *const p = (struct gl_viewport_inputs *) v;
    GET_CURRENT_CONTEXT(ctx);

    if (MESA_VERBOSE & VERBOSE_API)
       _mesa_debug(ctx, "glViewportArrayv %d %d\n", first, count);

    if ((first + count) > ctx->Const.MaxViewports) {
       _mesa_error(ctx, GL_INVALID_VALUE,
                   "glViewportArrayv: first (%d) + count (%d) > MaxViewports "
                   "(%d)",
                   first, count, ctx->Const.MaxViewports);
       return;
    }

    /* Verify width & height */
    for (i = 0; i < count; i++) {
       if (p[i].Width < 0 || p[i].Height < 0) {
          _mesa_error(ctx, GL_INVALID_VALUE,
                      "glViewportArrayv: index (%d) width or height < 0 "
                      "(%f, %f)",
                      i + first, p[i].Width, p[i].Height);
          return;
       }
    }

    for (i = 0; i < count; i++)
       set_viewport_no_notify(ctx, i + first,
                              p[i].X, p[i].Y,
                              p[i].Width, p[i].Height);

    if (ctx->Driver.Viewport)
       ctx->Driver.Viewport(ctx);
 }

 static void
 ViewportIndexedf(GLuint index, GLfloat x, GLfloat y,
                  GLfloat w, GLfloat h, const char *function)
 {
    GET_CURRENT_CONTEXT(ctx);

    if (MESA_VERBOSE & VERBOSE_API)
       _mesa_debug(ctx, "%s(%d, %f, %f, %f, %f)\n",
                   function, index, x, y, w, h);

    if (index >= ctx->Const.MaxViewports) {
       _mesa_error(ctx, GL_INVALID_VALUE,
                   "%s: index (%d) >= MaxViewports (%d)",
                   function, index, ctx->Const.MaxViewports);
       return;
    }

    /* Verify width & height */
    if (w < 0 || h < 0) {
       _mesa_error(ctx, GL_INVALID_VALUE,
                   "%s: index (%d) width or height < 0 (%f, %f)",
                   function, index, w, h);
       return;
    }

    _mesa_set_viewport(ctx, index, x, y, w, h);
 }

 void GLAPIENTRY
 _mesa_ViewportIndexedf(GLuint index, GLfloat x, GLfloat y,
                        GLfloat w, GLfloat h)
 {
    ViewportIndexedf(index, x, y, w, h, "glViewportIndexedf");
 }

 void GLAPIENTRY
 _mesa_ViewportIndexedfv(GLuint index, const GLfloat *v)
 {
    ViewportIndexedf(index, v[0], v[1], v[2], v[3], "glViewportIndexedfv");
 }

 static void
 set_depth_range_no_notify(struct gl_context *ctx, unsigned idx,
                           GLclampd nearval, GLclampd farval)
 {
    if (ctx->ViewportArray[idx].Near == nearval &&
        ctx->ViewportArray[idx].Far == farval)
       return;

    ctx->ViewportArray[idx].Near = CLAMP(nearval, 0.0, 1.0);
    ctx->ViewportArray[idx].Far = CLAMP(farval, 0.0, 1.0);
    ctx->NewState |= _NEW_VIEWPORT;
 }

 void
 _mesa_set_depth_range(struct gl_context *ctx, unsigned idx,
                       GLclampd nearval, GLclampd farval)
 {
    set_depth_range_no_notify(ctx, idx, nearval, farval);

    if (ctx->Driver.DepthRange)
       ctx->Driver.DepthRange(ctx);
 }

 /**
  * 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)
 {
    unsigned i;
    GET_CURRENT_CONTEXT(ctx);

    FLUSH_VERTICES(ctx, 0);

    if (MESA_VERBOSE&VERBOSE_API)
       _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);

    /* The GL_ARB_viewport_array spec says:
     *
     *     "DepthRange sets the depth range for all viewports to the same
     *     values and is equivalent (assuming no errors are generated) to:
     *
     *     for (uint i = 0; i < MAX_VIEWPORTS; i++)
     *         DepthRangeIndexed(i, n, f);"
     *
     * Set the depth range for all of the viewports supported by the
     * implementation, but only signal the driver once at the end.
     */
    for (i = 0; i < ctx->Const.MaxViewports; i++)
       set_depth_range_no_notify(ctx, i, nearval, farval);

    if (ctx->Driver.DepthRange) {
       ctx->Driver.DepthRange(ctx);
    }
 }

 void GLAPIENTRY
 _mesa_DepthRangef(GLclampf nearval, GLclampf farval)
 {
    _mesa_DepthRange(nearval, farval);
 }

 /**
  * Update a range DepthRange values
  *
  * \param first   starting array index
  * \param count   count of DepthRange items to update
  * \param v       pointer to memory containing
  *                GLclampd near and far clip-plane values
  */
 void GLAPIENTRY
 _mesa_DepthRangeArrayv(GLuint first, GLsizei count, const GLclampd *v)
 {
    int i;
    const struct gl_depthrange_inputs *const p =
       (struct gl_depthrange_inputs *) v;
    GET_CURRENT_CONTEXT(ctx);

    if (MESA_VERBOSE & VERBOSE_API)
       _mesa_debug(ctx, "glDepthRangeArrayv %d %d\n", first, count);

    if ((first + count) > ctx->Const.MaxViewports) {
       _mesa_error(ctx, GL_INVALID_VALUE,
                   "glDepthRangev: first (%d) + count (%d) >= MaxViewports (%d)",
                   first, count, ctx->Const.MaxViewports);
       return;
    }

    for (i = 0; i < count; i++)
       set_depth_range_no_notify(ctx, i + first, p[i].Near, p[i].Far);

    if (ctx->Driver.DepthRange)
       ctx->Driver.DepthRange(ctx);
 }

 void GLAPIENTRY
 _mesa_DepthRangeArrayfvOES(GLuint first, GLsizei count, const GLfloat *v)
 {
    int i;
    GET_CURRENT_CONTEXT(ctx);

    if (MESA_VERBOSE & VERBOSE_API)
       _mesa_debug(ctx, "glDepthRangeArrayfv %d %d\n", first, count);

    if ((first + count) > ctx->Const.MaxViewports) {
       _mesa_error(ctx, GL_INVALID_VALUE,
                   "glDepthRangeArrayfv: first (%d) + count (%d) >= MaxViewports (%d)",
                   first, count, ctx->Const.MaxViewports);
       return;
    }

    for (i = 0; i < count; i++)
       set_depth_range_no_notify(ctx, i + first, v[i * 2], v[i * 2 + 1]);

    if (ctx->Driver.DepthRange)
       ctx->Driver.DepthRange(ctx);
 }

 /**
  * Update a single DepthRange
  *
  * \param index    array index to update
  * \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_DepthRangeIndexed(GLuint index, GLclampd nearval, GLclampd farval)
 {
    GET_CURRENT_CONTEXT(ctx);

    if (MESA_VERBOSE & VERBOSE_API)
       _mesa_debug(ctx, "glDepthRangeIndexed(%d, %f, %f)\n",
                   index, nearval, farval);

    if (index >= ctx->Const.MaxViewports) {
       _mesa_error(ctx, GL_INVALID_VALUE,
                   "glDepthRangeIndexed: index (%d) >= MaxViewports (%d)",
                   index, ctx->Const.MaxViewports);
       return;
    }

    _mesa_set_depth_range(ctx, index, nearval, farval);
 }

 void GLAPIENTRY
 _mesa_DepthRangeIndexedfOES(GLuint index, GLfloat nearval, GLfloat farval)
 {
    _mesa_DepthRangeIndexed(index, nearval, farval);
 }

 /**
  * Initialize the context viewport attribute group.
  * \param ctx  the GL context.
  */
 void _mesa_init_viewport(struct gl_context *ctx)
 {
    unsigned i;

    ctx->Transform.ClipOrigin = GL_LOWER_LEFT;
    ctx->Transform.ClipDepthMode = GL_NEGATIVE_ONE_TO_ONE;

    /* Note: ctx->Const.MaxViewports may not have been set by the driver yet,
     * so just initialize all of them.
     */
    for (i = 0; i < MAX_VIEWPORTS; i++) {
       /* Viewport group */
       ctx->ViewportArray[i].X = 0;
       ctx->ViewportArray[i].Y = 0;
       ctx->ViewportArray[i].Width = 0;
       ctx->ViewportArray[i].Height = 0;
       ctx->ViewportArray[i].Near = 0.0;
       ctx->ViewportArray[i].Far = 1.0;
    }
 }


 extern void GLAPIENTRY
 _mesa_ClipControl(GLenum origin, GLenum depth)
 {
    GET_CURRENT_CONTEXT(ctx);

    if (MESA_VERBOSE&VERBOSE_API)
       _mesa_debug(ctx, "glClipControl(%s, %s)\n",
 	          _mesa_enum_to_string(origin),
                   _mesa_enum_to_string(depth));

    ASSERT_OUTSIDE_BEGIN_END(ctx);

    if (!ctx->Extensions.ARB_clip_control) {
       _mesa_error(ctx, GL_INVALID_OPERATION, "glClipControl");
       return;
    }

    if (origin != GL_LOWER_LEFT && origin != GL_UPPER_LEFT) {
       _mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
       return;
    }

    if (depth != GL_NEGATIVE_ONE_TO_ONE && depth != GL_ZERO_TO_ONE) {
       _mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
       return;
    }

    if (ctx->Transform.ClipOrigin == origin &&
        ctx->Transform.ClipDepthMode == depth)
       return;

    /* Affects transform state and the viewport transform */
    FLUSH_VERTICES(ctx, _NEW_TRANSFORM | _NEW_VIEWPORT);

    if (ctx->Transform.ClipOrigin != origin) {
       ctx->Transform.ClipOrigin = origin;

       /* Affects the winding order of the front face. */
       ctx->NewState |= _NEW_POLYGON;

       if (ctx->Driver.FrontFace)
          ctx->Driver.FrontFace(ctx, ctx->Polygon.FrontFace);
    }

    if (ctx->Transform.ClipDepthMode != depth) {
       ctx->Transform.ClipDepthMode = depth;

       if (ctx->Driver.DepthRange)
          ctx->Driver.DepthRange(ctx);
    }
 }

 /**
  * Computes the scaling and the translation part of the
  * viewport transform matrix of the \param i-th viewport
  * and writes that into \param scale and \param translate.
  */
 void
 _mesa_get_viewport_xform(struct gl_context *ctx, unsigned i,
                          float scale[3], float translate[3])
 {
    float x = ctx->ViewportArray[i].X;
    float y = ctx->ViewportArray[i].Y;
    float half_width = 0.5f * ctx->ViewportArray[i].Width;
    float half_height = 0.5f * ctx->ViewportArray[i].Height;
    double n = ctx->ViewportArray[i].Near;
    double f = ctx->ViewportArray[i].Far;

    scale[0] = half_width;
    translate[0] = half_width + x;
    if (ctx->Transform.ClipOrigin == GL_UPPER_LEFT) {
       scale[1] = -half_height;
    } else {
       scale[1] = half_height;
    }
    translate[1] = half_height + y;

    if (ctx->Transform.ClipDepthMode == GL_NEGATIVE_ONE_TO_ONE) {
       scale[2] = 0.5 * (f - n);
       translate[2] = 0.5 * (n + f);
    } else {
       scale[2] = f - n;
       translate[2] = n;
    }
 }
	/*
	* 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 "enums.h"
	#include "macros.h"
	#include "mtypes.h"
	#include "viewport.h"

	static void
	set_viewport_no_notify(struct gl_context *ctx, unsigned idx,
	GLfloat x, GLfloat y,
	GLfloat width, GLfloat height)
	{
	/* clamp width and height to the implementation dependent range */
	width = MIN2(width, (GLfloat) ctx->Const.MaxViewportWidth);
	height = MIN2(height, (GLfloat) ctx->Const.MaxViewportHeight);

	/* The GL_ARB_viewport_array spec says:
	*
	* "The location of the viewport's bottom-left corner, given by (x,y),
	* are clamped to be within the implementation-dependent viewport
	* bounds range. The viewport bounds range [min, max] tuple may be
	* determined by calling GetFloatv with the symbolic constant
	* VIEWPORT_BOUNDS_RANGE (see section 6.1)."
	*/
	if (ctx->Extensions.ARB_viewport_array \|\|
	(ctx->Extensions.OES_viewport_array &&
	_mesa_is_gles31(ctx))) {
	x = CLAMP(x,
	ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
	y = CLAMP(y,
	ctx->Const.ViewportBounds.Min, ctx->Const.ViewportBounds.Max);
	}

	if (ctx->ViewportArray[idx].X == x &&
	ctx->ViewportArray[idx].Width == width &&
	ctx->ViewportArray[idx].Y == y &&
	ctx->ViewportArray[idx].Height == height)
	return;

	ctx->ViewportArray[idx].X = x;
	ctx->ViewportArray[idx].Width = width;
	ctx->ViewportArray[idx].Y = y;
	ctx->ViewportArray[idx].Height = height;
	ctx->NewState \|= _NEW_VIEWPORT;
	}

	struct gl_viewport_inputs {
	GLfloat X, Y; /*< position /
	GLfloat Width, Height; /*< size /
	};

	struct gl_depthrange_inputs {
	GLdouble Near, Far; /*< Depth buffer range /
	};

	/**
	* 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)
	{
	unsigned i;
	GET_CURRENT_CONTEXT(ctx);
	FLUSH_VERTICES(ctx, 0);

	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;
	}

	/* The GL_ARB_viewport_array spec says:
	*
	* "Viewport sets the parameters for all viewports to the same values
	* and is equivalent (assuming no errors are generated) to:
	*
	* for (uint i = 0; i < MAX_VIEWPORTS; i++)
	* ViewportIndexedf(i, 1, (float)x, (float)y, (float)w, (float)h);"
	*
	* Set all of the viewports supported by the implementation, but only
	* signal the driver once at the end.
	*/
	for (i = 0; i < ctx->Const.MaxViewports; i++)
	set_viewport_no_notify(ctx, i, x, y, width, height);

	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);
	}
	}


	/**
	* Set new viewport parameters and update derived state.
	* Usually called from _mesa_Viewport().
	*
	* \param ctx GL context.
	* \param idx Index of the viewport to be updated.
	* \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, unsigned idx, GLfloat x, GLfloat y,
	GLfloat width, GLfloat height)
	{
	set_viewport_no_notify(ctx, idx, x, y, width, height);

	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);
	}
	}

	void GLAPIENTRY
	_mesa_ViewportArrayv(GLuint first, GLsizei count, const GLfloat *v)
	{
	int i;
	const struct gl_viewport_inputs const p = (struct gl_viewport_inputs ) v;
	GET_CURRENT_CONTEXT(ctx);

	if (MESA_VERBOSE & VERBOSE_API)
	_mesa_debug(ctx, "glViewportArrayv %d %d\n", first, count);

	if ((first + count) > ctx->Const.MaxViewports) {
	_mesa_error(ctx, GL_INVALID_VALUE,
	"glViewportArrayv: first (%d) + count (%d) > MaxViewports "
	"(%d)",
	first, count, ctx->Const.MaxViewports);
	return;
	}

	/* Verify width & height */
	for (i = 0; i < count; i++) {
	if (p[i].Width < 0 \|\| p[i].Height < 0) {
	_mesa_error(ctx, GL_INVALID_VALUE,
	"glViewportArrayv: index (%d) width or height < 0 "
	"(%f, %f)",
	i + first, p[i].Width, p[i].Height);
	return;
	}
	}

	for (i = 0; i < count; i++)
	set_viewport_no_notify(ctx, i + first,
	p[i].X, p[i].Y,
	p[i].Width, p[i].Height);

	if (ctx->Driver.Viewport)
	ctx->Driver.Viewport(ctx);
	}

	static void
	ViewportIndexedf(GLuint index, GLfloat x, GLfloat y,
	GLfloat w, GLfloat h, const char *function)
	{
	GET_CURRENT_CONTEXT(ctx);

	if (MESA_VERBOSE & VERBOSE_API)
	_mesa_debug(ctx, "%s(%d, %f, %f, %f, %f)\n",
	function, index, x, y, w, h);

	if (index >= ctx->Const.MaxViewports) {
	_mesa_error(ctx, GL_INVALID_VALUE,
	"%s: index (%d) >= MaxViewports (%d)",
	function, index, ctx->Const.MaxViewports);
	return;
	}

	/* Verify width & height */
	if (w < 0 \|\| h < 0) {
	_mesa_error(ctx, GL_INVALID_VALUE,
	"%s: index (%d) width or height < 0 (%f, %f)",
	function, index, w, h);
	return;
	}

	_mesa_set_viewport(ctx, index, x, y, w, h);
	}

	void GLAPIENTRY
	_mesa_ViewportIndexedf(GLuint index, GLfloat x, GLfloat y,
	GLfloat w, GLfloat h)
	{
	ViewportIndexedf(index, x, y, w, h, "glViewportIndexedf");
	}

	void GLAPIENTRY
	_mesa_ViewportIndexedfv(GLuint index, const GLfloat *v)
	{
	ViewportIndexedf(index, v[0], v[1], v[2], v[3], "glViewportIndexedfv");
	}

	static void
	set_depth_range_no_notify(struct gl_context *ctx, unsigned idx,
	GLclampd nearval, GLclampd farval)
	{
	if (ctx->ViewportArray[idx].Near == nearval &&
	ctx->ViewportArray[idx].Far == farval)
	return;

	ctx->ViewportArray[idx].Near = CLAMP(nearval, 0.0, 1.0);
	ctx->ViewportArray[idx].Far = CLAMP(farval, 0.0, 1.0);
	ctx->NewState \|= _NEW_VIEWPORT;
	}

	void
	_mesa_set_depth_range(struct gl_context *ctx, unsigned idx,
	GLclampd nearval, GLclampd farval)
	{
	set_depth_range_no_notify(ctx, idx, nearval, farval);

	if (ctx->Driver.DepthRange)
	ctx->Driver.DepthRange(ctx);
	}

	/**
	* 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)
	{
	unsigned i;
	GET_CURRENT_CONTEXT(ctx);

	FLUSH_VERTICES(ctx, 0);

	if (MESA_VERBOSE&VERBOSE_API)
	_mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);

	/* The GL_ARB_viewport_array spec says:
	*
	* "DepthRange sets the depth range for all viewports to the same
	* values and is equivalent (assuming no errors are generated) to:
	*
	* for (uint i = 0; i < MAX_VIEWPORTS; i++)
	* DepthRangeIndexed(i, n, f);"
	*
	* Set the depth range for all of the viewports supported by the
	* implementation, but only signal the driver once at the end.
	*/
	for (i = 0; i < ctx->Const.MaxViewports; i++)
	set_depth_range_no_notify(ctx, i, nearval, farval);

	if (ctx->Driver.DepthRange) {
	ctx->Driver.DepthRange(ctx);
	}
	}

	void GLAPIENTRY
	_mesa_DepthRangef(GLclampf nearval, GLclampf farval)
	{
	_mesa_DepthRange(nearval, farval);
	}

	/**
	* Update a range DepthRange values
	*
	* \param first starting array index
	* \param count count of DepthRange items to update
	* \param v pointer to memory containing
	* GLclampd near and far clip-plane values
	*/
	void GLAPIENTRY
	_mesa_DepthRangeArrayv(GLuint first, GLsizei count, const GLclampd *v)
	{
	int i;
	const struct gl_depthrange_inputs *const p =
	(struct gl_depthrange_inputs *) v;
	GET_CURRENT_CONTEXT(ctx);

	if (MESA_VERBOSE & VERBOSE_API)
	_mesa_debug(ctx, "glDepthRangeArrayv %d %d\n", first, count);

	if ((first + count) > ctx->Const.MaxViewports) {
	_mesa_error(ctx, GL_INVALID_VALUE,
	"glDepthRangev: first (%d) + count (%d) >= MaxViewports (%d)",
	first, count, ctx->Const.MaxViewports);
	return;
	}

	for (i = 0; i < count; i++)
	set_depth_range_no_notify(ctx, i + first, p[i].Near, p[i].Far);

	if (ctx->Driver.DepthRange)
	ctx->Driver.DepthRange(ctx);
	}

	void GLAPIENTRY
	_mesa_DepthRangeArrayfvOES(GLuint first, GLsizei count, const GLfloat *v)
	{
	int i;
	GET_CURRENT_CONTEXT(ctx);

	if (MESA_VERBOSE & VERBOSE_API)
	_mesa_debug(ctx, "glDepthRangeArrayfv %d %d\n", first, count);

	if ((first + count) > ctx->Const.MaxViewports) {
	_mesa_error(ctx, GL_INVALID_VALUE,
	"glDepthRangeArrayfv: first (%d) + count (%d) >= MaxViewports (%d)",
	first, count, ctx->Const.MaxViewports);
	return;
	}

	for (i = 0; i < count; i++)
	set_depth_range_no_notify(ctx, i + first, v[i * 2], v[i * 2 + 1]);

	if (ctx->Driver.DepthRange)
	ctx->Driver.DepthRange(ctx);
	}

	/**
	* Update a single DepthRange
	*
	* \param index array index to update
	* \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_DepthRangeIndexed(GLuint index, GLclampd nearval, GLclampd farval)
	{
	GET_CURRENT_CONTEXT(ctx);

	if (MESA_VERBOSE & VERBOSE_API)
	_mesa_debug(ctx, "glDepthRangeIndexed(%d, %f, %f)\n",
	index, nearval, farval);

	if (index >= ctx->Const.MaxViewports) {
	_mesa_error(ctx, GL_INVALID_VALUE,
	"glDepthRangeIndexed: index (%d) >= MaxViewports (%d)",
	index, ctx->Const.MaxViewports);
	return;
	}

	_mesa_set_depth_range(ctx, index, nearval, farval);
	}

	void GLAPIENTRY
	_mesa_DepthRangeIndexedfOES(GLuint index, GLfloat nearval, GLfloat farval)
	{
	_mesa_DepthRangeIndexed(index, nearval, farval);
	}

	/**
	* Initialize the context viewport attribute group.
	* \param ctx the GL context.
	*/
	void _mesa_init_viewport(struct gl_context *ctx)
	{
	unsigned i;

	ctx->Transform.ClipOrigin = GL_LOWER_LEFT;
	ctx->Transform.ClipDepthMode = GL_NEGATIVE_ONE_TO_ONE;

	/* Note: ctx->Const.MaxViewports may not have been set by the driver yet,
	* so just initialize all of them.
	*/
	for (i = 0; i < MAX_VIEWPORTS; i++) {
	/* Viewport group */
	ctx->ViewportArray[i].X = 0;
	ctx->ViewportArray[i].Y = 0;
	ctx->ViewportArray[i].Width = 0;
	ctx->ViewportArray[i].Height = 0;
	ctx->ViewportArray[i].Near = 0.0;
	ctx->ViewportArray[i].Far = 1.0;
	}
	}


	extern void GLAPIENTRY
	_mesa_ClipControl(GLenum origin, GLenum depth)
	{
	GET_CURRENT_CONTEXT(ctx);

	if (MESA_VERBOSE&VERBOSE_API)
	_mesa_debug(ctx, "glClipControl(%s, %s)\n",
	_mesa_enum_to_string(origin),
	_mesa_enum_to_string(depth));

	ASSERT_OUTSIDE_BEGIN_END(ctx);

	if (!ctx->Extensions.ARB_clip_control) {
	_mesa_error(ctx, GL_INVALID_OPERATION, "glClipControl");
	return;
	}

	if (origin != GL_LOWER_LEFT && origin != GL_UPPER_LEFT) {
	_mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
	return;
	}

	if (depth != GL_NEGATIVE_ONE_TO_ONE && depth != GL_ZERO_TO_ONE) {
	_mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
	return;
	}

	if (ctx->Transform.ClipOrigin == origin &&
	ctx->Transform.ClipDepthMode == depth)
	return;

	/* Affects transform state and the viewport transform */
	FLUSH_VERTICES(ctx, _NEW_TRANSFORM \| _NEW_VIEWPORT);

	if (ctx->Transform.ClipOrigin != origin) {
	ctx->Transform.ClipOrigin = origin;

	/* Affects the winding order of the front face. */
	ctx->NewState \|= _NEW_POLYGON;

	if (ctx->Driver.FrontFace)
	ctx->Driver.FrontFace(ctx, ctx->Polygon.FrontFace);
	}

	if (ctx->Transform.ClipDepthMode != depth) {
	ctx->Transform.ClipDepthMode = depth;

	if (ctx->Driver.DepthRange)
	ctx->Driver.DepthRange(ctx);
	}
	}

	/**
	* Computes the scaling and the translation part of the
	* viewport transform matrix of the \param i-th viewport
	* and writes that into \param scale and \param translate.
	*/
	void
	_mesa_get_viewport_xform(struct gl_context *ctx, unsigned i,
	float scale[3], float translate[3])
	{
	float x = ctx->ViewportArray[i].X;
	float y = ctx->ViewportArray[i].Y;
	float half_width = 0.5f * ctx->ViewportArray[i].Width;
	float half_height = 0.5f * ctx->ViewportArray[i].Height;
	double n = ctx->ViewportArray[i].Near;
	double f = ctx->ViewportArray[i].Far;

	scale[0] = half_width;
	translate[0] = half_width + x;
	if (ctx->Transform.ClipOrigin == GL_UPPER_LEFT) {
	scale[1] = -half_height;
	} else {
	scale[1] = half_height;
	}
	translate[1] = half_height + y;

	if (ctx->Transform.ClipDepthMode == GL_NEGATIVE_ONE_TO_ONE) {
	scale[2] = 0.5 * (f - n);
	translate[2] = 0.5 * (n + f);
	} else {
	scale[2] = f - n;
	translate[2] = n;
	}
	}