src/mesa/state_tracker/st_atom_blend.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28  /*
  29   * Authors:
  30   *   Keith Whitwell <keithw@vmware.com>
  31   *   Brian Paul
  32   */
  33
  34
  35 #include "st_context.h"
  36 #include "st_atom.h"
  37
  38 #include "pipe/p_context.h"
  39 #include "pipe/p_defines.h"
  40 #include "cso_cache/cso_context.h"
  41
  42 #include "framebuffer.h"
  43 #include "main/blend.h"
  44 #include "main/glformats.h"
  45 #include "main/macros.h"
  46
  47 /**
  48  * Convert GLenum blend tokens to pipe tokens.
  49  * Both blend factors and blend funcs are accepted.
  50  */
  51 static GLuint
  52 translate_blend(GLenum blend)
  53 {
  54    switch (blend) {
  55    /* blend functions */
  56    case GL_FUNC_ADD:
  57       return PIPE_BLEND_ADD;
  58    case GL_FUNC_SUBTRACT:
  59       return PIPE_BLEND_SUBTRACT;
  60    case GL_FUNC_REVERSE_SUBTRACT:
  61       return PIPE_BLEND_REVERSE_SUBTRACT;
  62    case GL_MIN:
  63       return PIPE_BLEND_MIN;
  64    case GL_MAX:
  65       return PIPE_BLEND_MAX;
  66
  67    /* blend factors */
  68    case GL_ONE:
  69       return PIPE_BLENDFACTOR_ONE;
  70    case GL_SRC_COLOR:
  71       return PIPE_BLENDFACTOR_SRC_COLOR;
  72    case GL_SRC_ALPHA:
  73       return PIPE_BLENDFACTOR_SRC_ALPHA;
  74    case GL_DST_ALPHA:
  75       return PIPE_BLENDFACTOR_DST_ALPHA;
  76    case GL_DST_COLOR:
  77       return PIPE_BLENDFACTOR_DST_COLOR;
  78    case GL_SRC_ALPHA_SATURATE:
  79       return PIPE_BLENDFACTOR_SRC_ALPHA_SATURATE;
  80    case GL_CONSTANT_COLOR:
  81       return PIPE_BLENDFACTOR_CONST_COLOR;
  82    case GL_CONSTANT_ALPHA:
  83       return PIPE_BLENDFACTOR_CONST_ALPHA;
  84    case GL_SRC1_COLOR:
  85       return PIPE_BLENDFACTOR_SRC1_COLOR;
  86    case GL_SRC1_ALPHA:
  87       return PIPE_BLENDFACTOR_SRC1_ALPHA;
  88    case GL_ZERO:
  89       return PIPE_BLENDFACTOR_ZERO;
  90    case GL_ONE_MINUS_SRC_COLOR:
  91       return PIPE_BLENDFACTOR_INV_SRC_COLOR;
  92    case GL_ONE_MINUS_SRC_ALPHA:
  93       return PIPE_BLENDFACTOR_INV_SRC_ALPHA;
  94    case GL_ONE_MINUS_DST_COLOR:
  95       return PIPE_BLENDFACTOR_INV_DST_COLOR;
  96    case GL_ONE_MINUS_DST_ALPHA:
  97       return PIPE_BLENDFACTOR_INV_DST_ALPHA;
  98    case GL_ONE_MINUS_CONSTANT_COLOR:
  99       return PIPE_BLENDFACTOR_INV_CONST_COLOR;
 100    case GL_ONE_MINUS_CONSTANT_ALPHA:
 101       return PIPE_BLENDFACTOR_INV_CONST_ALPHA;
 102    case GL_ONE_MINUS_SRC1_COLOR:
 103       return PIPE_BLENDFACTOR_INV_SRC1_COLOR;
 104    case GL_ONE_MINUS_SRC1_ALPHA:
 105       return PIPE_BLENDFACTOR_INV_SRC1_ALPHA;
 106    default:
 107       assert("invalid GL token in translate_blend()" == NULL);
 108       return 0;
 109    }
 110 }
 111
 112 /**
 113  * Figure out if colormasks are different per rt.
 114  */
 115 static GLboolean
 116 colormask_per_rt(const struct gl_context *ctx, unsigned num_cb)
 117 {
 118    GLbitfield full_mask = _mesa_replicate_colormask(0xf, num_cb);
 119    GLbitfield repl_mask0 =
 120       _mesa_replicate_colormask(GET_COLORMASK(ctx->Color.ColorMask, 0),
 121                                 num_cb);
 122
 123    return (ctx->Color.ColorMask & full_mask) != repl_mask0;
 124 }
 125
 126 /**
 127  * Figure out if blend enables/state are different per rt.
 128  */
 129 static GLboolean
 130 blend_per_rt(const struct st_context *st, unsigned num_cb)
 131 {
 132    const struct gl_context *ctx = st->ctx;
 133    GLbitfield cb_mask = u_bit_consecutive(0, num_cb);
 134    GLbitfield blend_enabled = ctx->Color.BlendEnabled & cb_mask;
 135
 136    if (blend_enabled && blend_enabled != cb_mask) {
 137       /* This can only happen if GL_EXT_draw_buffers2 is enabled */
 138       return GL_TRUE;
 139    }
 140    if (ctx->Color._BlendFuncPerBuffer || ctx->Color._BlendEquationPerBuffer) {
 141       /* this can only happen if GL_ARB_draw_buffers_blend is enabled */
 142       return GL_TRUE;
 143    }
 144    if (ctx->DrawBuffer->_IntegerBuffers &&
 145        (ctx->DrawBuffer->_IntegerBuffers != cb_mask)) {
 146       /* If there is a mix of integer/non-integer buffers then blending
 147        * must be handled on a per buffer basis. */
 148       return GL_TRUE;
 149    }
 150
 151    if (st->needs_rgb_dst_alpha_override && ctx->DrawBuffer->_RGBBuffers) {
 152       /* Overriding requires independent blend functions (not just enables),
 153        * require drivers exposing PIPE_CAP_RGB_OVERRIDE_DST_ALPHA_BLEND to
 154        * also expose PIPE_CAP_INDEP_BLEND_FUNC.
 155        */
 156       assert(st->has_indep_blend_func);
 157
 158       /* If some of the buffers are RGB, we may need to override blend
 159        * factors that reference destination-alpha to constants.  We may
 160        * need different blend factor overrides per buffer (say one uses
 161        * a DST_ALPHA factor and another uses INV_DST_ALPHA), so we flip
 162        * on independent blending.  This may not be required in all cases,
 163        * but burning the CPU to figure it out is probably not worthwhile.
 164        */
 165       return GL_TRUE;
 166    }
 167
 168    return GL_FALSE;
 169 }
 170
 171 /**
 172  * Modify blend function to force destination alpha to 1.0
 173  *
 174  * If \c function specifies a blend function that uses destination alpha,
 175  * replace it with a function that hard-wires destination alpha to 1.0.
 176  * This is useful when emulating a GL RGB format with an RGBA pipe_format.
 177  */
 178 static enum pipe_blendfactor
 179 fix_xrgb_alpha(enum pipe_blendfactor factor)
 180 {
 181    switch (factor) {
 182    case PIPE_BLENDFACTOR_DST_ALPHA:
 183       return PIPE_BLENDFACTOR_ONE;
 184
 185    case PIPE_BLENDFACTOR_INV_DST_ALPHA:
 186    case PIPE_BLENDFACTOR_SRC_ALPHA_SATURATE:
 187       return PIPE_BLENDFACTOR_ZERO;
 188    default:
 189       return factor;
 190    }
 191 }
 192
 193 void
 194 st_update_blend( struct st_context *st )
 195 {
 196    struct pipe_blend_state *blend = &st->state.blend;
 197    const struct gl_context *ctx = st->ctx;
 198    unsigned num_cb = st->state.fb_num_cb;
 199    unsigned num_state = 1;
 200    unsigned i, j;
 201
 202    memset(blend, 0, sizeof(*blend));
 203
 204    blend->max_rt = MAX2(1, num_cb) - 1;
 205
 206    if (num_cb > 1 &&
 207        (blend_per_rt(st, num_cb) || colormask_per_rt(ctx, num_cb))) {
 208       num_state = num_cb;
 209       blend->independent_blend_enable = 1;
 210    }
 211
 212    for (i = 0; i < num_state; i++)
 213       blend->rt[i].colormask = GET_COLORMASK(ctx->Color.ColorMask, i);
 214
 215    if (ctx->Color.ColorLogicOpEnabled) {
 216       /* logicop enabled */
 217       blend->logicop_enable = 1;
 218       blend->logicop_func = ctx->Color._LogicOp;
 219    }
 220    else if (ctx->Color.BlendEnabled &&
 221             ctx->Color._AdvancedBlendMode == BLEND_NONE) {
 222       /* blending enabled */
 223       for (i = 0, j = 0; i < num_state; i++) {
 224          if (!(ctx->Color.BlendEnabled & (1 << i)) ||
 225              (ctx->DrawBuffer->_IntegerBuffers & (1 << i)) ||
 226              !blend->rt[i].colormask)
 227             continue;
 228
 229          if (ctx->Extensions.ARB_draw_buffers_blend)
 230             j = i;
 231
 232          blend->rt[i].blend_enable = 1;
 233          blend->rt[i].rgb_func =
 234             translate_blend(ctx->Color.Blend[j].EquationRGB);
 235
 236          if (ctx->Color.Blend[i].EquationRGB == GL_MIN ||
 237              ctx->Color.Blend[i].EquationRGB == GL_MAX) {
 238             /* Min/max are special */
 239             blend->rt[i].rgb_src_factor = PIPE_BLENDFACTOR_ONE;
 240             blend->rt[i].rgb_dst_factor = PIPE_BLENDFACTOR_ONE;
 241          }
 242          else {
 243             blend->rt[i].rgb_src_factor =
 244                translate_blend(ctx->Color.Blend[j].SrcRGB);
 245             blend->rt[i].rgb_dst_factor =
 246                translate_blend(ctx->Color.Blend[j].DstRGB);
 247          }
 248
 249          blend->rt[i].alpha_func =
 250             translate_blend(ctx->Color.Blend[j].EquationA);
 251
 252          if (ctx->Color.Blend[i].EquationA == GL_MIN ||
 253              ctx->Color.Blend[i].EquationA == GL_MAX) {
 254             /* Min/max are special */
 255             blend->rt[i].alpha_src_factor = PIPE_BLENDFACTOR_ONE;
 256             blend->rt[i].alpha_dst_factor = PIPE_BLENDFACTOR_ONE;
 257          }
 258          else {
 259             blend->rt[i].alpha_src_factor =
 260                translate_blend(ctx->Color.Blend[j].SrcA);
 261             blend->rt[i].alpha_dst_factor =
 262                translate_blend(ctx->Color.Blend[j].DstA);
 263          }
 264
 265          const struct gl_renderbuffer *rb =
 266             ctx->DrawBuffer->_ColorDrawBuffers[i];
 267
 268          if (st->needs_rgb_dst_alpha_override && rb &&
 269              (ctx->DrawBuffer->_RGBBuffers & (1 << i))) {
 270             struct pipe_rt_blend_state *rt = &blend->rt[i];
 271             rt->rgb_src_factor = fix_xrgb_alpha(rt->rgb_src_factor);
 272             rt->rgb_dst_factor = fix_xrgb_alpha(rt->rgb_dst_factor);
 273             rt->alpha_src_factor = fix_xrgb_alpha(rt->alpha_src_factor);
 274             rt->alpha_dst_factor = fix_xrgb_alpha(rt->alpha_dst_factor);
 275          }
 276       }
 277    }
 278    else {
 279       /* no blending / logicop */
 280    }
 281
 282    blend->dither = ctx->Color.DitherFlag;
 283
 284    if (_mesa_is_multisample_enabled(ctx) &&
 285        !(ctx->DrawBuffer->_IntegerBuffers & 0x1)) {
 286       /* Unlike in gallium/d3d10 these operations are only performed
 287        * if both msaa is enabled and we have a multisample buffer.
 288        */
 289       blend->alpha_to_coverage = ctx->Multisample.SampleAlphaToCoverage;
 290       blend->alpha_to_one = ctx->Multisample.SampleAlphaToOne;
 291       blend->alpha_to_coverage_dither =
 292          ctx->Multisample.SampleAlphaToCoverageDitherControl !=
 293          GL_ALPHA_TO_COVERAGE_DITHER_DISABLE_NV;
 294    }
 295
 296    cso_set_blend(st->cso_context, blend);
 297 }
 298
 299 void
 300 st_update_blend_color(struct st_context *st)
 301 {
 302    struct pipe_blend_color bc;
 303
 304    COPY_4FV(bc.color, st->ctx->Color.BlendColorUnclamped);
 305    cso_set_blend_color(st->cso_context, &bc);
 306 }