src/mesa/drivers/dri/intel/intel_buffers.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
   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 TUNGSTEN GRAPHICS 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 #include "intel_context.h"
  29 #include "intel_buffers.h"
  30 #include "intel_fbo.h"
  31 #include "intel_batchbuffer.h"
  32 #include "main/framebuffer.h"
  33
  34 /**
  35  * Return pointer to current color drawing region, or NULL.
  36  */
  37 struct intel_region *
  38 intel_drawbuf_region(struct intel_context *intel)
  39 {
  40    struct intel_renderbuffer *irbColor =
  41       intel_renderbuffer(intel->ctx.DrawBuffer->_ColorDrawBuffers[0]);
  42    if (irbColor)
  43       return irbColor->region;
  44    else
  45       return NULL;
  46 }
  47
  48 /**
  49  * Return pointer to current color reading region, or NULL.
  50  */
  51 struct intel_region *
  52 intel_readbuf_region(struct intel_context *intel)
  53 {
  54    struct intel_renderbuffer *irb
  55       = intel_renderbuffer(intel->ctx.ReadBuffer->_ColorReadBuffer);
  56    if (irb)
  57       return irb->region;
  58    else
  59       return NULL;
  60 }
  61
  62 /**
  63  * Check if we're about to draw into the front color buffer.
  64  * If so, set the intel->front_buffer_dirty field to true.
  65  */
  66 void
  67 intel_check_front_buffer_rendering(struct intel_context *intel)
  68 {
  69    const struct gl_framebuffer *fb = intel->ctx.DrawBuffer;
  70    if (fb->Name == 0) {
  71       /* drawing to window system buffer */
  72       if (fb->_NumColorDrawBuffers > 0) {
  73          if (fb->_ColorDrawBufferIndexes[0] == BUFFER_FRONT_LEFT) {
  74             intel->front_buffer_dirty = GL_TRUE;
  75          }
  76       }
  77    }
  78 }
  79
  80
  81 /**
  82  * Update the hardware state for drawing into a window or framebuffer object.
  83  *
  84  * Called by glDrawBuffer, glBindFramebufferEXT, MakeCurrent, and other
  85  * places within the driver.
  86  *
  87  * Basically, this needs to be called any time the current framebuffer
  88  * changes, the renderbuffers change, or we need to draw into different
  89  * color buffers.
  90  */
  91 void
  92 intel_draw_buffer(GLcontext * ctx, struct gl_framebuffer *fb)
  93 {
  94    struct intel_context *intel = intel_context(ctx);
  95    struct intel_region *colorRegions[MAX_DRAW_BUFFERS], *depthRegion = NULL;
  96    struct intel_renderbuffer *irbDepth = NULL, *irbStencil = NULL;
  97
  98    if (!fb) {
  99       /* this can happen during the initial context initialization */
 100       return;
 101    }
 102
 103    /* Do this here, not core Mesa, since this function is called from
 104     * many places within the driver.
 105     */
 106    if (ctx->NewState & _NEW_BUFFERS) {
 107       /* this updates the DrawBuffer->_NumColorDrawBuffers fields, etc */
 108       _mesa_update_framebuffer(ctx);
 109       /* this updates the DrawBuffer's Width/Height if it's a FBO */
 110       _mesa_update_draw_buffer_bounds(ctx);
 111    }
 112
 113    if (fb->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 114       /* this may occur when we're called by glBindFrameBuffer() during
 115        * the process of someone setting up renderbuffers, etc.
 116        */
 117       /*_mesa_debug(ctx, "DrawBuffer: incomplete user FBO\n");*/
 118       return;
 119    }
 120
 121    /* How many color buffers are we drawing into?
 122     *
 123     * If there are zero buffers or the buffer is too big, don't configure any
 124     * regions for hardware drawing.  We'll fallback to software below.  Not
 125     * having regions set makes some of the software fallback paths faster.
 126     */
 127    if ((fb->Width > ctx->Const.MaxRenderbufferSize)
 128        || (fb->Height > ctx->Const.MaxRenderbufferSize)
 129        || (fb->_NumColorDrawBuffers == 0)) {
 130       /* writing to 0  */
 131       colorRegions[0] = NULL;
 132    }
 133    else if (fb->_NumColorDrawBuffers > 1) {
 134        int i;
 135        struct intel_renderbuffer *irb;
 136
 137        for (i = 0; i < fb->_NumColorDrawBuffers; i++) {
 138            irb = intel_renderbuffer(fb->_ColorDrawBuffers[i]);
 139            colorRegions[i] = irb ? irb->region : NULL;
 140        }
 141    }
 142    else {
 143       /* Get the intel_renderbuffer for the single colorbuffer we're drawing
 144        * into.
 145        */
 146       if (fb->Name == 0) {
 147          /* drawing to window system buffer */
 148          if (fb->_ColorDrawBufferIndexes[0] == BUFFER_FRONT_LEFT)
 149             colorRegions[0] = intel_get_rb_region(fb, BUFFER_FRONT_LEFT);
 150          else
 151             colorRegions[0] = intel_get_rb_region(fb, BUFFER_BACK_LEFT);
 152       }
 153       else {
 154          /* drawing to user-created FBO */
 155          struct intel_renderbuffer *irb;
 156          irb = intel_renderbuffer(fb->_ColorDrawBuffers[0]);
 157          colorRegions[0] = (irb && irb->region) ? irb->region : NULL;
 158       }
 159    }
 160
 161    if (!colorRegions[0]) {
 162       FALLBACK(intel, INTEL_FALLBACK_DRAW_BUFFER, GL_TRUE);
 163    }
 164    else {
 165       FALLBACK(intel, INTEL_FALLBACK_DRAW_BUFFER, GL_FALSE);
 166    }
 167
 168    /***
 169     *** Get depth buffer region and check if we need a software fallback.
 170     *** Note that the depth buffer is usually a DEPTH_STENCIL buffer.
 171     ***/
 172    if (fb->_DepthBuffer && fb->_DepthBuffer->Wrapped) {
 173       irbDepth = intel_renderbuffer(fb->_DepthBuffer->Wrapped);
 174       if (irbDepth && irbDepth->region) {
 175          FALLBACK(intel, INTEL_FALLBACK_DEPTH_BUFFER, GL_FALSE);
 176          depthRegion = irbDepth->region;
 177       }
 178       else {
 179          FALLBACK(intel, INTEL_FALLBACK_DEPTH_BUFFER, GL_TRUE);
 180          depthRegion = NULL;
 181       }
 182    }
 183    else {
 184       /* not using depth buffer */
 185       FALLBACK(intel, INTEL_FALLBACK_DEPTH_BUFFER, GL_FALSE);
 186       depthRegion = NULL;
 187    }
 188
 189    /***
 190     *** Stencil buffer
 191     *** This can only be hardware accelerated if we're using a
 192     *** combined DEPTH_STENCIL buffer.
 193     ***/
 194    if (fb->_StencilBuffer && fb->_StencilBuffer->Wrapped) {
 195       irbStencil = intel_renderbuffer(fb->_StencilBuffer->Wrapped);
 196       if (irbStencil && irbStencil->region) {
 197          ASSERT(irbStencil->Base.Format == MESA_FORMAT_S8_Z24);
 198          FALLBACK(intel, INTEL_FALLBACK_STENCIL_BUFFER, GL_FALSE);
 199       }
 200       else {
 201          FALLBACK(intel, INTEL_FALLBACK_STENCIL_BUFFER, GL_TRUE);
 202       }
 203    }
 204    else {
 205       /* XXX FBO: instead of FALSE, pass ctx->Stencil._Enabled ??? */
 206       FALLBACK(intel, INTEL_FALLBACK_STENCIL_BUFFER, GL_FALSE);
 207    }
 208
 209    /* If we have a (packed) stencil buffer attached but no depth buffer,
 210     * we still need to set up the shared depth/stencil state so we can use it.
 211     */
 212    if (depthRegion == NULL && irbStencil && irbStencil->region)
 213       depthRegion = irbStencil->region;
 214
 215    /*
 216     * Update depth and stencil test state
 217     */
 218    if (ctx->Driver.Enable) {
 219       ctx->Driver.Enable(ctx, GL_DEPTH_TEST,
 220                          (ctx->Depth.Test && fb->Visual.depthBits > 0));
 221       ctx->Driver.Enable(ctx, GL_STENCIL_TEST,
 222                          (ctx->Stencil.Enabled && fb->Visual.stencilBits > 0));
 223    }
 224    else {
 225       /* Mesa's Stencil._Enabled field is updated when
 226        * _NEW_BUFFERS | _NEW_STENCIL, but i965 code assumes that the value
 227        * only changes with _NEW_STENCIL (which seems sensible).  So flag it
 228        * here since this is the _NEW_BUFFERS path.
 229        */
 230       ctx->NewState |= (_NEW_DEPTH | _NEW_STENCIL);
 231    }
 232
 233    intel->vtbl.set_draw_region(intel, colorRegions, depthRegion,
 234                                fb->_NumColorDrawBuffers);
 235
 236    /* update viewport since it depends on window size */
 237 #ifdef I915
 238    intelCalcViewport(ctx);
 239 #else
 240    ctx->NewState |= _NEW_VIEWPORT;
 241 #endif
 242    /* Set state we know depends on drawable parameters:
 243     */
 244    if (ctx->Driver.Scissor)
 245       ctx->Driver.Scissor(ctx, ctx->Scissor.X, ctx->Scissor.Y,
 246                           ctx->Scissor.Width, ctx->Scissor.Height);
 247    intel->NewGLState |= _NEW_SCISSOR;
 248
 249    if (ctx->Driver.DepthRange)
 250       ctx->Driver.DepthRange(ctx,
 251                              ctx->Viewport.Near,
 252                              ctx->Viewport.Far);
 253
 254    /* Update culling direction which changes depending on the
 255     * orientation of the buffer:
 256     */
 257    if (ctx->Driver.FrontFace)
 258       ctx->Driver.FrontFace(ctx, ctx->Polygon.FrontFace);
 259    else
 260       ctx->NewState |= _NEW_POLYGON;
 261 }
 262
 263
 264 static void
 265 intelDrawBuffer(GLcontext * ctx, GLenum mode)
 266 {
 267    if ((ctx->DrawBuffer != NULL) && (ctx->DrawBuffer->Name == 0)) {
 268       struct intel_context *const intel = intel_context(ctx);
 269       const GLboolean was_front_buffer_rendering =
 270         intel->is_front_buffer_rendering;
 271
 272       intel->is_front_buffer_rendering = (mode == GL_FRONT_LEFT)
 273         || (mode == GL_FRONT);
 274
 275       /* If we weren't front-buffer rendering before but we are now, make sure
 276        * that the front-buffer has actually been allocated.
 277        */
 278       if (!was_front_buffer_rendering && intel->is_front_buffer_rendering) {
 279          intel_update_renderbuffers(intel->driContext,
 280                                     intel->driContext->driDrawablePriv);
 281       }
 282    }
 283
 284    intel_draw_buffer(ctx, ctx->DrawBuffer);
 285 }
 286
 287
 288 static void
 289 intelReadBuffer(GLcontext * ctx, GLenum mode)
 290 {
 291    if ((ctx->DrawBuffer != NULL) && (ctx->DrawBuffer->Name == 0)) {
 292       struct intel_context *const intel = intel_context(ctx);
 293       const GLboolean was_front_buffer_reading =
 294         intel->is_front_buffer_reading;
 295
 296       intel->is_front_buffer_reading = (mode == GL_FRONT_LEFT)
 297         || (mode == GL_FRONT);
 298
 299       /* If we weren't front-buffer reading before but we are now, make sure
 300        * that the front-buffer has actually been allocated.
 301        */
 302       if (!was_front_buffer_reading && intel->is_front_buffer_reading) {
 303          intel_update_renderbuffers(intel->driContext,
 304                                     intel->driContext->driDrawablePriv);
 305       }
 306    }
 307
 308    if (ctx->ReadBuffer == ctx->DrawBuffer) {
 309       /* This will update FBO completeness status.
 310        * A framebuffer will be incomplete if the GL_READ_BUFFER setting
 311        * refers to a missing renderbuffer.  Calling glReadBuffer can set
 312        * that straight and can make the drawing buffer complete.
 313        */
 314       intel_draw_buffer(ctx, ctx->DrawBuffer);
 315    }
 316    /* Generally, functions which read pixels (glReadPixels, glCopyPixels, etc)
 317     * reference ctx->ReadBuffer and do appropriate state checks.
 318     */
 319 }
 320
 321
 322 void
 323 intelInitBufferFuncs(struct dd_function_table *functions)
 324 {
 325    functions->DrawBuffer = intelDrawBuffer;
 326    functions->ReadBuffer = intelReadBuffer;
 327 }