src/parsec/disk-image/parsec/parsec-benchmark/pkgs/libs/mesa/src/src/mesa/drivers/dri/i915/i830_texblend.c - public/gem5-resources - Git at Google

 /**************************************************************************
  *
  * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
  * 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, sub license, 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 (including the
  * next paragraph) 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 NON-INFRINGEMENT.
  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS 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.
  *
  **************************************************************************/

 #include "glheader.h"
 #include "macros.h"
 #include "mtypes.h"
 #include "simple_list.h"
 #include "enums.h"
 #include "texformat.h"
 #include "texstore.h"

 #include "mm.h"

 #include "intel_screen.h"
 #include "intel_ioctl.h"
 #include "intel_tex.h"

 #include "i830_context.h"
 #include "i830_reg.h"


 /* ================================================================
  * Texture combine functions
  */
 static GLuint
 pass_through(GLuint * state, GLuint blendUnit)
 {
    state[0] = (_3DSTATE_MAP_BLEND_OP_CMD(blendUnit) |
                TEXPIPE_COLOR |
                ENABLE_TEXOUTPUT_WRT_SEL |
                TEXOP_OUTPUT_CURRENT |
                DISABLE_TEX_CNTRL_STAGE |
                TEXOP_SCALE_1X | TEXOP_MODIFY_PARMS | TEXBLENDOP_ARG1);
    state[1] = (_3DSTATE_MAP_BLEND_OP_CMD(blendUnit) |
                TEXPIPE_ALPHA |
                ENABLE_TEXOUTPUT_WRT_SEL |
                TEXOP_OUTPUT_CURRENT |
                TEXOP_SCALE_1X | TEXOP_MODIFY_PARMS | TEXBLENDOP_ARG1);
    state[2] = (_3DSTATE_MAP_BLEND_ARG_CMD(blendUnit) |
                TEXPIPE_COLOR |
                TEXBLEND_ARG1 |
                TEXBLENDARG_MODIFY_PARMS | TEXBLENDARG_CURRENT);
    state[3] = (_3DSTATE_MAP_BLEND_ARG_CMD(blendUnit) |
                TEXPIPE_ALPHA |
                TEXBLEND_ARG1 |
                TEXBLENDARG_MODIFY_PARMS | TEXBLENDARG_CURRENT);

    return 4;
 }

 static GLuint
 emit_factor(GLuint blendUnit, GLuint * state, GLuint count,
             const GLfloat * factor)
 {
    GLubyte r, g, b, a;
    GLuint col;

    if (0)
       fprintf(stderr, "emit constant %d: %.2f %.2f %.2f %.2f\n",
               blendUnit, factor[0], factor[1], factor[2], factor[3]);

    UNCLAMPED_FLOAT_TO_UBYTE(r, factor[0]);
    UNCLAMPED_FLOAT_TO_UBYTE(g, factor[1]);
    UNCLAMPED_FLOAT_TO_UBYTE(b, factor[2]);
    UNCLAMPED_FLOAT_TO_UBYTE(a, factor[3]);

    col = ((a << 24) | (r << 16) | (g << 8) | b);

    state[count++] = _3DSTATE_COLOR_FACTOR_N_CMD(blendUnit);
    state[count++] = col;

    return count;
 }


 static INLINE GLuint
 GetTexelOp(GLint unit)
 {
    switch (unit) {
    case 0:
       return TEXBLENDARG_TEXEL0;
    case 1:
       return TEXBLENDARG_TEXEL1;
    case 2:
       return TEXBLENDARG_TEXEL2;
    case 3:
       return TEXBLENDARG_TEXEL3;
    default:
       return TEXBLENDARG_TEXEL0;
    }
 }


 /**
  * Calculate the hardware instuctions to setup the current texture enviromnemt
  * settings.  Since \c gl_texture_unit::_CurrentCombine is used, both
  * "classic" texture enviroments and GL_ARB_texture_env_combine type texture
  * environments are treated identically.
  *
  * \todo
  * This function should return \c GLboolean.  When \c GL_FALSE is returned,
  * it means that an environment is selected that the hardware cannot do.  This
  * is the way the Radeon and R200 drivers work.
  *
  * \todo
  * Looking at i830_3d_regs.h, it seems the i830 can do part of
  * GL_ATI_texture_env_combine3.  It can handle using \c GL_ONE and
  * \c GL_ZERO as combine inputs (which the code already supports).  It can
  * also handle the \c GL_MODULATE_ADD_ATI mode.  Is it worth investigating
  * partial support for the extension?
  */
 GLuint
 i830SetTexEnvCombine(struct i830_context * i830,
                      const struct gl_tex_env_combine_state * combine,
                      GLint blendUnit,
                      GLuint texel_op, GLuint * state, const GLfloat * factor)
 {
    const GLuint numColorArgs = combine->_NumArgsRGB;
    const GLuint numAlphaArgs = combine->_NumArgsA;

    GLuint blendop;
    GLuint ablendop;
    GLuint args_RGB[3];
    GLuint args_A[3];
    GLuint rgb_shift;
    GLuint alpha_shift;
    GLboolean need_factor = 0;
    int i;
    unsigned used;
    static const GLuint tex_blend_rgb[3] = {
       TEXPIPE_COLOR | TEXBLEND_ARG1 | TEXBLENDARG_MODIFY_PARMS,
       TEXPIPE_COLOR | TEXBLEND_ARG2 | TEXBLENDARG_MODIFY_PARMS,
       TEXPIPE_COLOR | TEXBLEND_ARG0 | TEXBLENDARG_MODIFY_PARMS,
    };
    static const GLuint tex_blend_a[3] = {
       TEXPIPE_ALPHA | TEXBLEND_ARG1 | TEXBLENDARG_MODIFY_PARMS,
       TEXPIPE_ALPHA | TEXBLEND_ARG2 | TEXBLENDARG_MODIFY_PARMS,
       TEXPIPE_ALPHA | TEXBLEND_ARG0 | TEXBLENDARG_MODIFY_PARMS,
    };

    if (INTEL_DEBUG & DEBUG_TEXTURE)
       fprintf(stderr, "%s\n", __FUNCTION__);


    /* The EXT version of the DOT3 extension does not support the
     * scale factor, but the ARB version (and the version in OpenGL
     * 1.3) does.
     */
    switch (combine->ModeRGB) {
    case GL_DOT3_RGB_EXT:
       alpha_shift = combine->ScaleShiftA;
       rgb_shift = 0;
       break;

    case GL_DOT3_RGBA_EXT:
       alpha_shift = 0;
       rgb_shift = 0;
       break;

    default:
       rgb_shift = combine->ScaleShiftRGB;
       alpha_shift = combine->ScaleShiftA;
       break;
    }


    switch (combine->ModeRGB) {
    case GL_REPLACE:
       blendop = TEXBLENDOP_ARG1;
       break;
    case GL_MODULATE:
       blendop = TEXBLENDOP_MODULATE;
       break;
    case GL_ADD:
       blendop = TEXBLENDOP_ADD;
       break;
    case GL_ADD_SIGNED:
       blendop = TEXBLENDOP_ADDSIGNED;
       break;
    case GL_INTERPOLATE:
       blendop = TEXBLENDOP_BLEND;
       break;
    case GL_SUBTRACT:
       blendop = TEXBLENDOP_SUBTRACT;
       break;
    case GL_DOT3_RGB_EXT:
    case GL_DOT3_RGB:
       blendop = TEXBLENDOP_DOT3;
       break;
    case GL_DOT3_RGBA_EXT:
    case GL_DOT3_RGBA:
       blendop = TEXBLENDOP_DOT3;
       break;
    default:
       return pass_through(state, blendUnit);
    }

    blendop |= (rgb_shift << TEXOP_SCALE_SHIFT);


    /* Handle RGB args */
    for (i = 0; i < 3; i++) {
       switch (combine->SourceRGB[i]) {
       case GL_TEXTURE:
          args_RGB[i] = texel_op;
          break;
       case GL_TEXTURE0:
       case GL_TEXTURE1:
       case GL_TEXTURE2:
       case GL_TEXTURE3:
          args_RGB[i] = GetTexelOp(combine->SourceRGB[i] - GL_TEXTURE0);
          break;
       case GL_CONSTANT:
          args_RGB[i] = TEXBLENDARG_FACTOR_N;
          need_factor = 1;
          break;
       case GL_PRIMARY_COLOR:
          args_RGB[i] = TEXBLENDARG_DIFFUSE;
          break;
       case GL_PREVIOUS:
          args_RGB[i] = TEXBLENDARG_CURRENT;
          break;
       default:
          return pass_through(state, blendUnit);
       }

       switch (combine->OperandRGB[i]) {
       case GL_SRC_COLOR:
          args_RGB[i] |= 0;
          break;
       case GL_ONE_MINUS_SRC_COLOR:
          args_RGB[i] |= TEXBLENDARG_INV_ARG;
          break;
       case GL_SRC_ALPHA:
          args_RGB[i] |= TEXBLENDARG_REPLICATE_ALPHA;
          break;
       case GL_ONE_MINUS_SRC_ALPHA:
          args_RGB[i] |= (TEXBLENDARG_REPLICATE_ALPHA | TEXBLENDARG_INV_ARG);
          break;
       default:
          return pass_through(state, blendUnit);
       }
    }


    /* Need to knobble the alpha calculations of TEXBLENDOP_DOT4 to
     * match the spec.  Can't use DOT3 as it won't propogate values
     * into alpha as required:
     *
     * Note - the global factor is set up with alpha == .5, so
     * the alpha part of the DOT4 calculation should be zero.
     */
    if (combine->ModeRGB == GL_DOT3_RGBA_EXT ||
        combine->ModeRGB == GL_DOT3_RGBA) {
       ablendop = TEXBLENDOP_DOT4;
       args_A[0] = TEXBLENDARG_FACTOR;   /* the global factor */
       args_A[1] = TEXBLENDARG_FACTOR;
       args_A[2] = TEXBLENDARG_FACTOR;
    }
    else {
       switch (combine->ModeA) {
       case GL_REPLACE:
          ablendop = TEXBLENDOP_ARG1;
          break;
       case GL_MODULATE:
          ablendop = TEXBLENDOP_MODULATE;
          break;
       case GL_ADD:
          ablendop = TEXBLENDOP_ADD;
          break;
       case GL_ADD_SIGNED:
          ablendop = TEXBLENDOP_ADDSIGNED;
          break;
       case GL_INTERPOLATE:
          ablendop = TEXBLENDOP_BLEND;
          break;
       case GL_SUBTRACT:
          ablendop = TEXBLENDOP_SUBTRACT;
          break;
       default:
          return pass_through(state, blendUnit);
       }


       ablendop |= (alpha_shift << TEXOP_SCALE_SHIFT);

       /* Handle A args */
       for (i = 0; i < 3; i++) {
          switch (combine->SourceA[i]) {
          case GL_TEXTURE:
             args_A[i] = texel_op;
             break;
          case GL_TEXTURE0:
          case GL_TEXTURE1:
          case GL_TEXTURE2:
          case GL_TEXTURE3:
             args_A[i] = GetTexelOp(combine->SourceA[i] - GL_TEXTURE0);
             break;
          case GL_CONSTANT:
             args_A[i] = TEXBLENDARG_FACTOR_N;
             need_factor = 1;
             break;
          case GL_PRIMARY_COLOR:
             args_A[i] = TEXBLENDARG_DIFFUSE;
             break;
          case GL_PREVIOUS:
             args_A[i] = TEXBLENDARG_CURRENT;
             break;
          default:
             return pass_through(state, blendUnit);
          }

          switch (combine->OperandA[i]) {
          case GL_SRC_ALPHA:
             args_A[i] |= 0;
             break;
          case GL_ONE_MINUS_SRC_ALPHA:
             args_A[i] |= TEXBLENDARG_INV_ARG;
             break;
          default:
             return pass_through(state, blendUnit);
          }
       }
    }


    /* Native Arg1 == Arg0 in GL_EXT_texture_env_combine spec */
    /* Native Arg2 == Arg1 in GL_EXT_texture_env_combine spec */
    /* Native Arg0 == Arg2 in GL_EXT_texture_env_combine spec */

    /* When we render we need to figure out which is the last really enabled
     * tex unit, and put last stage on it
     */


    /* Build color & alpha pipelines */

    used = 0;
    state[used++] = (_3DSTATE_MAP_BLEND_OP_CMD(blendUnit) |
                     TEXPIPE_COLOR |
                     ENABLE_TEXOUTPUT_WRT_SEL |
                     TEXOP_OUTPUT_CURRENT |
                     DISABLE_TEX_CNTRL_STAGE | TEXOP_MODIFY_PARMS | blendop);
    state[used++] = (_3DSTATE_MAP_BLEND_OP_CMD(blendUnit) |
                     TEXPIPE_ALPHA |
                     ENABLE_TEXOUTPUT_WRT_SEL |
                     TEXOP_OUTPUT_CURRENT | TEXOP_MODIFY_PARMS | ablendop);

    for (i = 0; i < numColorArgs; i++) {
       state[used++] = (_3DSTATE_MAP_BLEND_ARG_CMD(blendUnit) |
                        tex_blend_rgb[i] | args_RGB[i]);
    }

    for (i = 0; i < numAlphaArgs; i++) {
       state[used++] = (_3DSTATE_MAP_BLEND_ARG_CMD(blendUnit) |
                        tex_blend_a[i] | args_A[i]);
    }


    if (need_factor)
       return emit_factor(blendUnit, state, used, factor);
    else
       return used;
 }


 static void
 emit_texblend(struct i830_context *i830, GLuint unit, GLuint blendUnit,
               GLboolean last_stage)
 {
    struct gl_texture_unit *texUnit = &i830->intel.ctx.Texture.Unit[unit];
    GLuint tmp[I830_TEXBLEND_SIZE], tmp_sz;


    if (0)
       fprintf(stderr, "%s unit %d\n", __FUNCTION__, unit);

    /* Update i830->state.TexBlend
     */
    tmp_sz = i830SetTexEnvCombine(i830, texUnit->_CurrentCombine, blendUnit,
                                  GetTexelOp(unit), tmp, texUnit->EnvColor);

    if (last_stage)
       tmp[0] |= TEXOP_LAST_STAGE;

    if (tmp_sz != i830->state.TexBlendWordsUsed[blendUnit] ||
        memcmp(tmp, i830->state.TexBlend[blendUnit],
               tmp_sz * sizeof(GLuint))) {

       I830_STATECHANGE(i830, I830_UPLOAD_TEXBLEND(blendUnit));
       memcpy(i830->state.TexBlend[blendUnit], tmp, tmp_sz * sizeof(GLuint));
       i830->state.TexBlendWordsUsed[blendUnit] = tmp_sz;
    }

    I830_ACTIVESTATE(i830, I830_UPLOAD_TEXBLEND(blendUnit), GL_TRUE);
 }

 static void
 emit_passthrough(struct i830_context *i830)
 {
    GLuint tmp[I830_TEXBLEND_SIZE], tmp_sz;
    GLuint unit = 0;

    tmp_sz = pass_through(tmp, unit);
    tmp[0] |= TEXOP_LAST_STAGE;

    if (tmp_sz != i830->state.TexBlendWordsUsed[unit] ||
        memcmp(tmp, i830->state.TexBlend[unit], tmp_sz * sizeof(GLuint))) {

       I830_STATECHANGE(i830, I830_UPLOAD_TEXBLEND(unit));
       memcpy(i830->state.TexBlend[unit], tmp, tmp_sz * sizeof(GLuint));
       i830->state.TexBlendWordsUsed[unit] = tmp_sz;
    }

    I830_ACTIVESTATE(i830, I830_UPLOAD_TEXBLEND(unit), GL_TRUE);
 }

 void
 i830EmitTextureBlend(struct i830_context *i830)
 {
    GLcontext *ctx = &i830->intel.ctx;
    GLuint unit, last_stage = 0, blendunit = 0;

    I830_ACTIVESTATE(i830, I830_UPLOAD_TEXBLEND_ALL, GL_FALSE);

    if (ctx->Texture._EnabledUnits) {
       for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++)
          if (ctx->Texture.Unit[unit]._ReallyEnabled)
             last_stage = unit;

       for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++)
          if (ctx->Texture.Unit[unit]._ReallyEnabled)
             emit_texblend(i830, unit, blendunit++, last_stage == unit);
    }
    else {
       emit_passthrough(i830);
    }
 }
	/**************************************************************************
	*
	* Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
	* 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, sub license, 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 (including the
	* next paragraph) 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 NON-INFRINGEMENT.
	* IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS 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.
	*
	**************************************************************************/

	#include "glheader.h"
	#include "macros.h"
	#include "mtypes.h"
	#include "simple_list.h"
	#include "enums.h"
	#include "texformat.h"
	#include "texstore.h"

	#include "mm.h"

	#include "intel_screen.h"
	#include "intel_ioctl.h"
	#include "intel_tex.h"

	#include "i830_context.h"
	#include "i830_reg.h"


	/* ================================================================
	* Texture combine functions
	*/
	static GLuint
	pass_through(GLuint * state, GLuint blendUnit)
	{
	state[0] = (_3DSTATE_MAP_BLEND_OP_CMD(blendUnit) \|
	TEXPIPE_COLOR \|
	ENABLE_TEXOUTPUT_WRT_SEL \|
	TEXOP_OUTPUT_CURRENT \|
	DISABLE_TEX_CNTRL_STAGE \|
	TEXOP_SCALE_1X \| TEXOP_MODIFY_PARMS \| TEXBLENDOP_ARG1);
	state[1] = (_3DSTATE_MAP_BLEND_OP_CMD(blendUnit) \|
	TEXPIPE_ALPHA \|
	ENABLE_TEXOUTPUT_WRT_SEL \|
	TEXOP_OUTPUT_CURRENT \|
	TEXOP_SCALE_1X \| TEXOP_MODIFY_PARMS \| TEXBLENDOP_ARG1);
	state[2] = (_3DSTATE_MAP_BLEND_ARG_CMD(blendUnit) \|
	TEXPIPE_COLOR \|
	TEXBLEND_ARG1 \|
	TEXBLENDARG_MODIFY_PARMS \| TEXBLENDARG_CURRENT);
	state[3] = (_3DSTATE_MAP_BLEND_ARG_CMD(blendUnit) \|
	TEXPIPE_ALPHA \|
	TEXBLEND_ARG1 \|
	TEXBLENDARG_MODIFY_PARMS \| TEXBLENDARG_CURRENT);

	return 4;
	}

	static GLuint
	emit_factor(GLuint blendUnit, GLuint * state, GLuint count,
	const GLfloat * factor)
	{
	GLubyte r, g, b, a;
	GLuint col;

	if (0)
	fprintf(stderr, "emit constant %d: %.2f %.2f %.2f %.2f\n",
	blendUnit, factor[0], factor[1], factor[2], factor[3]);

	UNCLAMPED_FLOAT_TO_UBYTE(r, factor[0]);
	UNCLAMPED_FLOAT_TO_UBYTE(g, factor[1]);
	UNCLAMPED_FLOAT_TO_UBYTE(b, factor[2]);
	UNCLAMPED_FLOAT_TO_UBYTE(a, factor[3]);

	col = ((a << 24) \| (r << 16) \| (g << 8) \| b);

	state[count++] = _3DSTATE_COLOR_FACTOR_N_CMD(blendUnit);
	state[count++] = col;

	return count;
	}


	static INLINE GLuint
	GetTexelOp(GLint unit)
	{
	switch (unit) {
	case 0:
	return TEXBLENDARG_TEXEL0;
	case 1:
	return TEXBLENDARG_TEXEL1;
	case 2:
	return TEXBLENDARG_TEXEL2;
	case 3:
	return TEXBLENDARG_TEXEL3;
	default:
	return TEXBLENDARG_TEXEL0;
	}
	}


	/**
	* Calculate the hardware instuctions to setup the current texture enviromnemt
	* settings. Since \c gl_texture_unit::_CurrentCombine is used, both
	* "classic" texture enviroments and GL_ARB_texture_env_combine type texture
	* environments are treated identically.
	*
	* \todo
	* This function should return \c GLboolean. When \c GL_FALSE is returned,
	* it means that an environment is selected that the hardware cannot do. This
	* is the way the Radeon and R200 drivers work.
	*
	* \todo
	* Looking at i830_3d_regs.h, it seems the i830 can do part of
	* GL_ATI_texture_env_combine3. It can handle using \c GL_ONE and
	* \c GL_ZERO as combine inputs (which the code already supports). It can
	* also handle the \c GL_MODULATE_ADD_ATI mode. Is it worth investigating
	* partial support for the extension?
	*/
	GLuint
	i830SetTexEnvCombine(struct i830_context * i830,
	const struct gl_tex_env_combine_state * combine,
	GLint blendUnit,
	GLuint texel_op, GLuint * state, const GLfloat * factor)
	{
	const GLuint numColorArgs = combine->_NumArgsRGB;
	const GLuint numAlphaArgs = combine->_NumArgsA;

	GLuint blendop;
	GLuint ablendop;
	GLuint args_RGB[3];
	GLuint args_A[3];
	GLuint rgb_shift;
	GLuint alpha_shift;
	GLboolean need_factor = 0;
	int i;
	unsigned used;
	static const GLuint tex_blend_rgb[3] = {
	TEXPIPE_COLOR \| TEXBLEND_ARG1 \| TEXBLENDARG_MODIFY_PARMS,
	TEXPIPE_COLOR \| TEXBLEND_ARG2 \| TEXBLENDARG_MODIFY_PARMS,
	TEXPIPE_COLOR \| TEXBLEND_ARG0 \| TEXBLENDARG_MODIFY_PARMS,
	};
	static const GLuint tex_blend_a[3] = {
	TEXPIPE_ALPHA \| TEXBLEND_ARG1 \| TEXBLENDARG_MODIFY_PARMS,
	TEXPIPE_ALPHA \| TEXBLEND_ARG2 \| TEXBLENDARG_MODIFY_PARMS,
	TEXPIPE_ALPHA \| TEXBLEND_ARG0 \| TEXBLENDARG_MODIFY_PARMS,
	};

	if (INTEL_DEBUG & DEBUG_TEXTURE)
	fprintf(stderr, "%s\n", __FUNCTION__);


	/* The EXT version of the DOT3 extension does not support the
	* scale factor, but the ARB version (and the version in OpenGL
	* 1.3) does.
	*/
	switch (combine->ModeRGB) {
	case GL_DOT3_RGB_EXT:
	alpha_shift = combine->ScaleShiftA;
	rgb_shift = 0;
	break;

	case GL_DOT3_RGBA_EXT:
	alpha_shift = 0;
	rgb_shift = 0;
	break;

	default:
	rgb_shift = combine->ScaleShiftRGB;
	alpha_shift = combine->ScaleShiftA;
	break;
	}


	switch (combine->ModeRGB) {
	case GL_REPLACE:
	blendop = TEXBLENDOP_ARG1;
	break;
	case GL_MODULATE:
	blendop = TEXBLENDOP_MODULATE;
	break;
	case GL_ADD:
	blendop = TEXBLENDOP_ADD;
	break;
	case GL_ADD_SIGNED:
	blendop = TEXBLENDOP_ADDSIGNED;
	break;
	case GL_INTERPOLATE:
	blendop = TEXBLENDOP_BLEND;
	break;
	case GL_SUBTRACT:
	blendop = TEXBLENDOP_SUBTRACT;
	break;
	case GL_DOT3_RGB_EXT:
	case GL_DOT3_RGB:
	blendop = TEXBLENDOP_DOT3;
	break;
	case GL_DOT3_RGBA_EXT:
	case GL_DOT3_RGBA:
	blendop = TEXBLENDOP_DOT3;
	break;
	default:
	return pass_through(state, blendUnit);
	}

	blendop \|= (rgb_shift << TEXOP_SCALE_SHIFT);


	/* Handle RGB args */
	for (i = 0; i < 3; i++) {
	switch (combine->SourceRGB[i]) {
	case GL_TEXTURE:
	args_RGB[i] = texel_op;
	break;
	case GL_TEXTURE0:
	case GL_TEXTURE1:
	case GL_TEXTURE2:
	case GL_TEXTURE3:
	args_RGB[i] = GetTexelOp(combine->SourceRGB[i] - GL_TEXTURE0);
	break;
	case GL_CONSTANT:
	args_RGB[i] = TEXBLENDARG_FACTOR_N;
	need_factor = 1;
	break;
	case GL_PRIMARY_COLOR:
	args_RGB[i] = TEXBLENDARG_DIFFUSE;
	break;
	case GL_PREVIOUS:
	args_RGB[i] = TEXBLENDARG_CURRENT;
	break;
	default:
	return pass_through(state, blendUnit);
	}

	switch (combine->OperandRGB[i]) {
	case GL_SRC_COLOR:
	args_RGB[i] \|= 0;
	break;
	case GL_ONE_MINUS_SRC_COLOR:
	args_RGB[i] \|= TEXBLENDARG_INV_ARG;
	break;
	case GL_SRC_ALPHA:
	args_RGB[i] \|= TEXBLENDARG_REPLICATE_ALPHA;
	break;
	case GL_ONE_MINUS_SRC_ALPHA:
	args_RGB[i] \|= (TEXBLENDARG_REPLICATE_ALPHA \| TEXBLENDARG_INV_ARG);
	break;
	default:
	return pass_through(state, blendUnit);
	}
	}


	/* Need to knobble the alpha calculations of TEXBLENDOP_DOT4 to
	* match the spec. Can't use DOT3 as it won't propogate values
	* into alpha as required:
	*
	* Note - the global factor is set up with alpha == .5, so
	* the alpha part of the DOT4 calculation should be zero.
	*/
	if (combine->ModeRGB == GL_DOT3_RGBA_EXT \|\|
	combine->ModeRGB == GL_DOT3_RGBA) {
	ablendop = TEXBLENDOP_DOT4;
	args_A[0] = TEXBLENDARG_FACTOR; /* the global factor */
	args_A[1] = TEXBLENDARG_FACTOR;
	args_A[2] = TEXBLENDARG_FACTOR;
	}
	else {
	switch (combine->ModeA) {
	case GL_REPLACE:
	ablendop = TEXBLENDOP_ARG1;
	break;
	case GL_MODULATE:
	ablendop = TEXBLENDOP_MODULATE;
	break;
	case GL_ADD:
	ablendop = TEXBLENDOP_ADD;
	break;
	case GL_ADD_SIGNED:
	ablendop = TEXBLENDOP_ADDSIGNED;
	break;
	case GL_INTERPOLATE:
	ablendop = TEXBLENDOP_BLEND;
	break;
	case GL_SUBTRACT:
	ablendop = TEXBLENDOP_SUBTRACT;
	break;
	default:
	return pass_through(state, blendUnit);
	}


	ablendop \|= (alpha_shift << TEXOP_SCALE_SHIFT);

	/* Handle A args */
	for (i = 0; i < 3; i++) {
	switch (combine->SourceA[i]) {
	case GL_TEXTURE:
	args_A[i] = texel_op;
	break;
	case GL_TEXTURE0:
	case GL_TEXTURE1:
	case GL_TEXTURE2:
	case GL_TEXTURE3:
	args_A[i] = GetTexelOp(combine->SourceA[i] - GL_TEXTURE0);
	break;
	case GL_CONSTANT:
	args_A[i] = TEXBLENDARG_FACTOR_N;
	need_factor = 1;
	break;
	case GL_PRIMARY_COLOR:
	args_A[i] = TEXBLENDARG_DIFFUSE;
	break;
	case GL_PREVIOUS:
	args_A[i] = TEXBLENDARG_CURRENT;
	break;
	default:
	return pass_through(state, blendUnit);
	}

	switch (combine->OperandA[i]) {
	case GL_SRC_ALPHA:
	args_A[i] \|= 0;
	break;
	case GL_ONE_MINUS_SRC_ALPHA:
	args_A[i] \|= TEXBLENDARG_INV_ARG;
	break;
	default:
	return pass_through(state, blendUnit);
	}
	}
	}



	/* Native Arg1 == Arg0 in GL_EXT_texture_env_combine spec */
	/* Native Arg2 == Arg1 in GL_EXT_texture_env_combine spec */
	/* Native Arg0 == Arg2 in GL_EXT_texture_env_combine spec */

	/* When we render we need to figure out which is the last really enabled
	* tex unit, and put last stage on it
	*/


	/* Build color & alpha pipelines */

	used = 0;
	state[used++] = (_3DSTATE_MAP_BLEND_OP_CMD(blendUnit) \|
	TEXPIPE_COLOR \|
	ENABLE_TEXOUTPUT_WRT_SEL \|
	TEXOP_OUTPUT_CURRENT \|
	DISABLE_TEX_CNTRL_STAGE \| TEXOP_MODIFY_PARMS \| blendop);
	state[used++] = (_3DSTATE_MAP_BLEND_OP_CMD(blendUnit) \|
	TEXPIPE_ALPHA \|
	ENABLE_TEXOUTPUT_WRT_SEL \|
	TEXOP_OUTPUT_CURRENT \| TEXOP_MODIFY_PARMS \| ablendop);

	for (i = 0; i < numColorArgs; i++) {
	state[used++] = (_3DSTATE_MAP_BLEND_ARG_CMD(blendUnit) \|
	tex_blend_rgb[i] \| args_RGB[i]);
	}

	for (i = 0; i < numAlphaArgs; i++) {
	state[used++] = (_3DSTATE_MAP_BLEND_ARG_CMD(blendUnit) \|
	tex_blend_a[i] \| args_A[i]);
	}


	if (need_factor)
	return emit_factor(blendUnit, state, used, factor);
	else
	return used;
	}


	static void
	emit_texblend(struct i830_context *i830, GLuint unit, GLuint blendUnit,
	GLboolean last_stage)
	{
	struct gl_texture_unit *texUnit = &i830->intel.ctx.Texture.Unit[unit];
	GLuint tmp[I830_TEXBLEND_SIZE], tmp_sz;


	if (0)
	fprintf(stderr, "%s unit %d\n", __FUNCTION__, unit);

	/* Update i830->state.TexBlend
	*/
	tmp_sz = i830SetTexEnvCombine(i830, texUnit->_CurrentCombine, blendUnit,
	GetTexelOp(unit), tmp, texUnit->EnvColor);

	if (last_stage)
	tmp[0] \|= TEXOP_LAST_STAGE;

	if (tmp_sz != i830->state.TexBlendWordsUsed[blendUnit] \|\|
	memcmp(tmp, i830->state.TexBlend[blendUnit],
	tmp_sz * sizeof(GLuint))) {

	I830_STATECHANGE(i830, I830_UPLOAD_TEXBLEND(blendUnit));
	memcpy(i830->state.TexBlend[blendUnit], tmp, tmp_sz * sizeof(GLuint));
	i830->state.TexBlendWordsUsed[blendUnit] = tmp_sz;
	}

	I830_ACTIVESTATE(i830, I830_UPLOAD_TEXBLEND(blendUnit), GL_TRUE);
	}

	static void
	emit_passthrough(struct i830_context *i830)
	{
	GLuint tmp[I830_TEXBLEND_SIZE], tmp_sz;
	GLuint unit = 0;

	tmp_sz = pass_through(tmp, unit);
	tmp[0] \|= TEXOP_LAST_STAGE;

	if (tmp_sz != i830->state.TexBlendWordsUsed[unit] \|\|
	memcmp(tmp, i830->state.TexBlend[unit], tmp_sz * sizeof(GLuint))) {

	I830_STATECHANGE(i830, I830_UPLOAD_TEXBLEND(unit));
	memcpy(i830->state.TexBlend[unit], tmp, tmp_sz * sizeof(GLuint));
	i830->state.TexBlendWordsUsed[unit] = tmp_sz;
	}

	I830_ACTIVESTATE(i830, I830_UPLOAD_TEXBLEND(unit), GL_TRUE);
	}

	void
	i830EmitTextureBlend(struct i830_context *i830)
	{
	GLcontext *ctx = &i830->intel.ctx;
	GLuint unit, last_stage = 0, blendunit = 0;

	I830_ACTIVESTATE(i830, I830_UPLOAD_TEXBLEND_ALL, GL_FALSE);

	if (ctx->Texture._EnabledUnits) {
	for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++)
	if (ctx->Texture.Unit[unit]._ReallyEnabled)
	last_stage = unit;

	for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++)
	if (ctx->Texture.Unit[unit]._ReallyEnabled)
	emit_texblend(i830, unit, blendunit++, last_stage == unit);
	}
	else {
	emit_passthrough(i830);
	}
	}