src/mesa/state_tracker/st_atom_scissor.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   */
  32
  33
  34 #include "main/macros.h"
  35 #include "main/framebuffer.h"
  36 #include "st_context.h"
  37 #include "pipe/p_context.h"
  38 #include "st_atom.h"
  39
  40
  41 /**
  42  * Scissor depends on the scissor box, and the framebuffer dimensions.
  43  */
  44 void
  45 st_update_scissor( struct st_context *st )
  46 {
  47    struct pipe_scissor_state scissor[PIPE_MAX_VIEWPORTS];
  48    const struct gl_context *ctx = st->ctx;
  49    const struct gl_framebuffer *fb = ctx->DrawBuffer;
  50    const unsigned int fb_width = _mesa_geometric_width(fb);
  51    const unsigned int fb_height = _mesa_geometric_height(fb);
  52    GLint miny, maxy;
  53    unsigned i;
  54    bool changed = false;
  55
  56    for (i = 0 ; i < st->state.num_viewports; i++) {
  57       scissor[i].minx = 0;
  58       scissor[i].miny = 0;
  59       scissor[i].maxx = fb_width;
  60       scissor[i].maxy = fb_height;
  61
  62       if (ctx->Scissor.EnableFlags & (1 << i)) {
  63          /* need to be careful here with xmax or ymax < 0 */
  64          GLint xmax = MAX2(0, ctx->Scissor.ScissorArray[i].X + ctx->Scissor.ScissorArray[i].Width);
  65          GLint ymax = MAX2(0, ctx->Scissor.ScissorArray[i].Y + ctx->Scissor.ScissorArray[i].Height);
  66
  67          if (ctx->Scissor.ScissorArray[i].X > (GLint)scissor[i].minx)
  68             scissor[i].minx = ctx->Scissor.ScissorArray[i].X;
  69          if (ctx->Scissor.ScissorArray[i].Y > (GLint)scissor[i].miny)
  70             scissor[i].miny = ctx->Scissor.ScissorArray[i].Y;
  71
  72          if (xmax < (GLint) scissor[i].maxx)
  73             scissor[i].maxx = xmax;
  74          if (ymax < (GLint) scissor[i].maxy)
  75             scissor[i].maxy = ymax;
  76
  77          /* check for null space */
  78          if (scissor[i].minx >= scissor[i].maxx || scissor[i].miny >= scissor[i].maxy)
  79             scissor[i].minx = scissor[i].miny = scissor[i].maxx = scissor[i].maxy = 0;
  80       }
  81
  82       /* Now invert Y if needed.
  83        * Gallium drivers use the convention Y=0=top for surfaces.
  84        */
  85       if (st->state.fb_orientation == Y_0_TOP) {
  86          miny = fb->Height - scissor[i].maxy;
  87          maxy = fb->Height - scissor[i].miny;
  88          scissor[i].miny = miny;
  89          scissor[i].maxy = maxy;
  90       }
  91
  92       if (memcmp(&scissor[i], &st->state.scissor[i], sizeof(scissor[0])) != 0) {
  93          /* state has changed */
  94          st->state.scissor[i] = scissor[i];  /* struct copy */
  95          changed = true;
  96       }
  97    }
  98
  99    if (changed) {
 100       struct pipe_context *pipe = st->pipe;
 101
 102       pipe->set_scissor_states(pipe, 0, st->state.num_viewports, scissor);
 103    }
 104 }
 105
 106 void
 107 st_update_window_rectangles(struct st_context *st)
 108 {
 109    struct pipe_scissor_state new_rects[PIPE_MAX_WINDOW_RECTANGLES];
 110    const struct gl_context *ctx = st->ctx;
 111    const struct gl_scissor_attrib *scissor = &ctx->Scissor;
 112    unsigned i;
 113    bool changed = false;
 114    unsigned num_rects = scissor->NumWindowRects;
 115    bool include = scissor->WindowRectMode == GL_INCLUSIVE_EXT;
 116
 117    if (ctx->DrawBuffer == ctx->WinSysDrawBuffer) {
 118       num_rects = 0;
 119       include = false;
 120    }
 121    for (i = 0; i < num_rects; i++) {
 122       const struct gl_scissor_rect *rect = &scissor->WindowRects[i];
 123       new_rects[i].minx = MAX2(rect->X, 0);
 124       new_rects[i].miny = MAX2(rect->Y, 0);
 125       new_rects[i].maxx = MAX2(rect->X + rect->Width, 0);
 126       new_rects[i].maxy = MAX2(rect->Y + rect->Height, 0);
 127    }
 128    if (num_rects > 0 && memcmp(new_rects, st->state.window_rects.rects,
 129                                num_rects * sizeof(struct pipe_scissor_state))) {
 130       memcpy(st->state.window_rects.rects, new_rects,
 131              num_rects * sizeof(struct pipe_scissor_state));
 132       changed = true;
 133    }
 134    if (st->state.window_rects.num != num_rects) {
 135       st->state.window_rects.num = num_rects;
 136       changed = true;
 137    }
 138    if (st->state.window_rects.include != include) {
 139       st->state.window_rects.include = include;
 140       changed = true;
 141    }
 142    if (changed)
 143       st->pipe->set_window_rectangles(
 144             st->pipe, include, num_rects, new_rects);
 145 }