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 /**
  36  * XXX move this into a new dri/common/cliprects.c file.
  37  */
  38 GLboolean
  39 intel_intersect_cliprects(drm_clip_rect_t * dst,
  40                           const drm_clip_rect_t * a,
  41                           const drm_clip_rect_t * b)
  42 {
  43    GLint bx = b->x1;
  44    GLint by = b->y1;
  45    GLint bw = b->x2 - bx;
  46    GLint bh = b->y2 - by;
  47
  48    if (bx < a->x1)
  49       bw -= a->x1 - bx, bx = a->x1;
  50    if (by < a->y1)
  51       bh -= a->y1 - by, by = a->y1;
  52    if (bx + bw > a->x2)
  53       bw = a->x2 - bx;
  54    if (by + bh > a->y2)
  55       bh = a->y2 - by;
  56    if (bw <= 0)
  57       return GL_FALSE;
  58    if (bh <= 0)
  59       return GL_FALSE;
  60
  61    dst->x1 = bx;
  62    dst->y1 = by;
  63    dst->x2 = bx + bw;
  64    dst->y2 = by + bh;
  65
  66    return GL_TRUE;
  67 }
  68
  69 /**
  70  * Return pointer to current color drawing region, or NULL.
  71  */
  72 struct intel_region *
  73 intel_drawbuf_region(struct intel_context *intel)
  74 {
  75    struct intel_renderbuffer *irbColor =
  76       intel_renderbuffer(intel->ctx.DrawBuffer->_ColorDrawBuffers[0]);
  77    if (irbColor)
  78       return irbColor->region;
  79    else
  80       return NULL;
  81 }
  82
  83 /**
  84  * Return pointer to current color reading region, or NULL.
  85  */
  86 struct intel_region *
  87 intel_readbuf_region(struct intel_context *intel)
  88 {
  89    struct intel_renderbuffer *irb
  90       = intel_renderbuffer(intel->ctx.ReadBuffer->_ColorReadBuffer);
  91    if (irb)
  92       return irb->region;
  93    else
  94       return NULL;
  95 }
  96
  97 void
  98 intel_get_cliprects(struct intel_context *intel,
  99                     struct drm_clip_rect **cliprects,
 100                     unsigned int *num_cliprects,
 101                     int *x_off, int *y_off)
 102 {
 103    intel->fboRect.x1 = 0;
 104    intel->fboRect.y1 = 0;
 105    intel->fboRect.x2 = intel->ctx.DrawBuffer->Width;
 106    intel->fboRect.y2 = intel->ctx.DrawBuffer->Height;
 107
 108    *cliprects = &intel->fboRect;
 109    *num_cliprects = 1;
 110    *x_off = 0;
 111    *y_off = 0;
 112 }
 113
 114
 115 /**
 116  * Check if we're about to draw into the front color buffer.
 117  * If so, set the intel->front_buffer_dirty field to true.
 118  */
 119 void
 120 intel_check_front_buffer_rendering(struct intel_context *intel)
 121 {
 122    const struct gl_framebuffer *fb = intel->ctx.DrawBuffer;
 123    if (fb->Name == 0) {
 124       /* drawing to window system buffer */
 125       if (fb->_NumColorDrawBuffers > 0) {
 126          if (fb->_ColorDrawBufferIndexes[0] == BUFFER_FRONT_LEFT) {
 127             intel->front_buffer_dirty = GL_TRUE;
 128          }
 129       }
 130    }
 131 }
 132
 133
 134 /**
 135  * Update the hardware state for drawing into a window or framebuffer object.
 136  *
 137  * Called by glDrawBuffer, glBindFramebufferEXT, MakeCurrent, and other
 138  * places within the driver.
 139  *
 140  * Basically, this needs to be called any time the current framebuffer
 141  * changes, the renderbuffers change, or we need to draw into different
 142  * color buffers.
 143  */
 144 void
 145 intel_draw_buffer(GLcontext * ctx, struct gl_framebuffer *fb)
 146 {
 147    struct intel_context *intel = intel_context(ctx);
 148    struct intel_region *colorRegions[MAX_DRAW_BUFFERS], *depthRegion = NULL;
 149    struct intel_renderbuffer *irbDepth = NULL, *irbStencil = NULL;
 150
 151    if (!fb) {
 152       /* this can happen during the initial context initialization */
 153       return;
 154    }
 155
 156    /* Do this here, not core Mesa, since this function is called from
 157     * many places within the driver.
 158     */
 159    if (ctx->NewState & _NEW_BUFFERS) {
 160       /* this updates the DrawBuffer->_NumColorDrawBuffers fields, etc */
 161       _mesa_update_framebuffer(ctx);
 162       /* this updates the DrawBuffer's Width/Height if it's a FBO */
 163       _mesa_update_draw_buffer_bounds(ctx);
 164    }
 165
 166    if (fb->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 167       /* this may occur when we're called by glBindFrameBuffer() during
 168        * the process of someone setting up renderbuffers, etc.
 169        */
 170       /*_mesa_debug(ctx, "DrawBuffer: incomplete user FBO\n");*/
 171       return;
 172    }
 173
 174    /* How many color buffers are we drawing into?
 175     *
 176     * If there are zero buffers or the buffer is too big, don't configure any
 177     * regions for hardware drawing.  We'll fallback to software below.  Not
 178     * having regions set makes some of the software fallback paths faster.
 179     */
 180    if ((fb->Width > ctx->Const.MaxRenderbufferSize)
 181        || (fb->Height > ctx->Const.MaxRenderbufferSize)
 182        || (fb->_NumColorDrawBuffers == 0)) {
 183       /* writing to 0  */
 184       colorRegions[0] = NULL;
 185    }
 186    else if (fb->_NumColorDrawBuffers > 1) {
 187        int i;
 188        struct intel_renderbuffer *irb;
 189
 190        for (i = 0; i < fb->_NumColorDrawBuffers; i++) {
 191            irb = intel_renderbuffer(fb->_ColorDrawBuffers[i]);
 192            colorRegions[i] = irb ? irb->region : NULL;
 193        }
 194    }
 195    else {
 196       /* Get the intel_renderbuffer for the single colorbuffer we're drawing
 197        * into.
 198        */
 199       if (fb->Name == 0) {
 200          /* drawing to window system buffer */
 201          if (fb->_ColorDrawBufferIndexes[0] == BUFFER_FRONT_LEFT)
 202             colorRegions[0] = intel_get_rb_region(fb, BUFFER_FRONT_LEFT);
 203          else
 204             colorRegions[0] = intel_get_rb_region(fb, BUFFER_BACK_LEFT);
 205       }
 206       else {
 207          /* drawing to user-created FBO */
 208          struct intel_renderbuffer *irb;
 209          irb = intel_renderbuffer(fb->_ColorDrawBuffers[0]);
 210          colorRegions[0] = (irb && irb->region) ? irb->region : NULL;
 211       }
 212    }
 213
 214    if (!colorRegions[0]) {
 215       FALLBACK(intel, INTEL_FALLBACK_DRAW_BUFFER, GL_TRUE);
 216    }
 217    else {
 218       FALLBACK(intel, INTEL_FALLBACK_DRAW_BUFFER, GL_FALSE);
 219    }
 220
 221    /***
 222     *** Get depth buffer region and check if we need a software fallback.
 223     *** Note that the depth buffer is usually a DEPTH_STENCIL buffer.
 224     ***/
 225    if (fb->_DepthBuffer && fb->_DepthBuffer->Wrapped) {
 226       irbDepth = intel_renderbuffer(fb->_DepthBuffer->Wrapped);
 227       if (irbDepth && irbDepth->region) {
 228          FALLBACK(intel, INTEL_FALLBACK_DEPTH_BUFFER, GL_FALSE);
 229          depthRegion = irbDepth->region;
 230       }
 231       else {
 232          FALLBACK(intel, INTEL_FALLBACK_DEPTH_BUFFER, GL_TRUE);
 233          depthRegion = NULL;
 234       }
 235    }
 236    else {
 237       /* not using depth buffer */
 238       FALLBACK(intel, INTEL_FALLBACK_DEPTH_BUFFER, GL_FALSE);
 239       depthRegion = NULL;
 240    }
 241
 242    /***
 243     *** Stencil buffer
 244     *** This can only be hardware accelerated if we're using a
 245     *** combined DEPTH_STENCIL buffer.
 246     ***/
 247    if (fb->_StencilBuffer && fb->_StencilBuffer->Wrapped) {
 248       irbStencil = intel_renderbuffer(fb->_StencilBuffer->Wrapped);
 249       if (irbStencil && irbStencil->region) {
 250          ASSERT(irbStencil->Base.Format == MESA_FORMAT_S8_Z24);
 251          FALLBACK(intel, INTEL_FALLBACK_STENCIL_BUFFER, GL_FALSE);
 252       }
 253       else {
 254          FALLBACK(intel, INTEL_FALLBACK_STENCIL_BUFFER, GL_TRUE);
 255       }
 256    }
 257    else {
 258       /* XXX FBO: instead of FALSE, pass ctx->Stencil._Enabled ??? */
 259       FALLBACK(intel, INTEL_FALLBACK_STENCIL_BUFFER, GL_FALSE);
 260    }
 261
 262    /* If we have a (packed) stencil buffer attached but no depth buffer,
 263     * we still need to set up the shared depth/stencil state so we can use it.
 264     */
 265    if (depthRegion == NULL && irbStencil && irbStencil->region)
 266       depthRegion = irbStencil->region;
 267
 268    /*
 269     * Update depth and stencil test state
 270     */
 271    if (ctx->Driver.Enable) {
 272       ctx->Driver.Enable(ctx, GL_DEPTH_TEST,
 273                          (ctx->Depth.Test && fb->Visual.depthBits > 0));
 274       ctx->Driver.Enable(ctx, GL_STENCIL_TEST,
 275                          (ctx->Stencil.Enabled && fb->Visual.stencilBits > 0));
 276    }
 277    else {
 278       /* Mesa's Stencil._Enabled field is updated when
 279        * _NEW_BUFFERS | _NEW_STENCIL, but i965 code assumes that the value
 280        * only changes with _NEW_STENCIL (which seems sensible).  So flag it
 281        * here since this is the _NEW_BUFFERS path.
 282        */
 283       ctx->NewState |= (_NEW_DEPTH | _NEW_STENCIL);
 284    }
 285
 286    intel->vtbl.set_draw_region(intel, colorRegions, depthRegion,
 287                                fb->_NumColorDrawBuffers);
 288
 289    /* update viewport since it depends on window size */
 290 #ifdef I915
 291    intelCalcViewport(ctx);
 292 #else
 293    ctx->NewState |= _NEW_VIEWPORT;
 294 #endif
 295    /* Set state we know depends on drawable parameters:
 296     */
 297    if (ctx->Driver.Scissor)
 298       ctx->Driver.Scissor(ctx, ctx->Scissor.X, ctx->Scissor.Y,
 299                           ctx->Scissor.Width, ctx->Scissor.Height);
 300    intel->NewGLState |= _NEW_SCISSOR;
 301
 302    if (ctx->Driver.DepthRange)
 303       ctx->Driver.DepthRange(ctx,
 304                              ctx->Viewport.Near,
 305                              ctx->Viewport.Far);
 306
 307    /* Update culling direction which changes depending on the
 308     * orientation of the buffer:
 309     */
 310    if (ctx->Driver.FrontFace)
 311       ctx->Driver.FrontFace(ctx, ctx->Polygon.FrontFace);
 312    else
 313       ctx->NewState |= _NEW_POLYGON;
 314 }
 315
 316
 317 static void
 318 intelDrawBuffer(GLcontext * ctx, GLenum mode)
 319 {
 320    if ((ctx->DrawBuffer != NULL) && (ctx->DrawBuffer->Name == 0)) {
 321       struct intel_context *const intel = intel_context(ctx);
 322       const GLboolean was_front_buffer_rendering =
 323         intel->is_front_buffer_rendering;
 324
 325       intel->is_front_buffer_rendering = (mode == GL_FRONT_LEFT)
 326         || (mode == GL_FRONT);
 327
 328       /* If we weren't front-buffer rendering before but we are now, make sure
 329        * that the front-buffer has actually been allocated.
 330        */
 331       if (!was_front_buffer_rendering && intel->is_front_buffer_rendering) {
 332          intel_update_renderbuffers(intel->driContext,
 333                                     intel->driContext->driDrawablePriv);
 334       }
 335    }
 336
 337    intel_draw_buffer(ctx, ctx->DrawBuffer);
 338 }
 339
 340
 341 static void
 342 intelReadBuffer(GLcontext * ctx, GLenum mode)
 343 {
 344    if ((ctx->DrawBuffer != NULL) && (ctx->DrawBuffer->Name == 0)) {
 345       struct intel_context *const intel = intel_context(ctx);
 346       const GLboolean was_front_buffer_reading =
 347         intel->is_front_buffer_reading;
 348
 349       intel->is_front_buffer_reading = (mode == GL_FRONT_LEFT)
 350         || (mode == GL_FRONT);
 351
 352       /* If we weren't front-buffer reading before but we are now, make sure
 353        * that the front-buffer has actually been allocated.
 354        */
 355       if (!was_front_buffer_reading && intel->is_front_buffer_reading) {
 356          intel_update_renderbuffers(intel->driContext,
 357                                     intel->driContext->driDrawablePriv);
 358       }
 359    }
 360
 361    if (ctx->ReadBuffer == ctx->DrawBuffer) {
 362       /* This will update FBO completeness status.
 363        * A framebuffer will be incomplete if the GL_READ_BUFFER setting
 364        * refers to a missing renderbuffer.  Calling glReadBuffer can set
 365        * that straight and can make the drawing buffer complete.
 366        */
 367       intel_draw_buffer(ctx, ctx->DrawBuffer);
 368    }
 369    /* Generally, functions which read pixels (glReadPixels, glCopyPixels, etc)
 370     * reference ctx->ReadBuffer and do appropriate state checks.
 371     */
 372 }
 373
 374
 375 void
 376 intelInitBufferFuncs(struct dd_function_table *functions)
 377 {
 378    functions->DrawBuffer = intelDrawBuffer;
 379    functions->ReadBuffer = intelReadBuffer;
 380 }