src/mesa/swrast/s_clear.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.1
   4  *
   5  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 #include "main/glheader.h"
  26 #include "main/colormac.h"
  27 #include "main/condrender.h"
  28 #include "main/macros.h"
  29 #include "main/imports.h"
  30 #include "main/mtypes.h"
  31
  32 #include "s_accum.h"
  33 #include "s_context.h"
  34 #include "s_depth.h"
  35 #include "s_masking.h"
  36 #include "s_stencil.h"
  37
  38
  39 /**
  40  * Clear the color buffer when glColorMask is in effect.
  41  */
  42 static void
  43 clear_rgba_buffer_with_masking(GLcontext *ctx, struct gl_renderbuffer *rb,
  44                                GLuint buf)
  45 {
  46    const GLint x = ctx->DrawBuffer->_Xmin;
  47    const GLint y = ctx->DrawBuffer->_Ymin;
  48    const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
  49    const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
  50    SWspan span;
  51    GLint i;
  52
  53    ASSERT(rb->PutRow);
  54
  55    /* Initialize color span with clear color */
  56    /* XXX optimize for clearcolor == black/zero (bzero) */
  57    INIT_SPAN(span, GL_BITMAP);
  58    span.end = width;
  59    span.arrayMask = SPAN_RGBA;
  60    span.array->ChanType = rb->DataType;
  61    if (span.array->ChanType == GL_UNSIGNED_BYTE) {
  62       GLubyte clearColor[4];
  63       UNCLAMPED_FLOAT_TO_UBYTE(clearColor[RCOMP], ctx->Color.ClearColor[0]);
  64       UNCLAMPED_FLOAT_TO_UBYTE(clearColor[GCOMP], ctx->Color.ClearColor[1]);
  65       UNCLAMPED_FLOAT_TO_UBYTE(clearColor[BCOMP], ctx->Color.ClearColor[2]);
  66       UNCLAMPED_FLOAT_TO_UBYTE(clearColor[ACOMP], ctx->Color.ClearColor[3]);
  67       for (i = 0; i < width; i++) {
  68          COPY_4UBV(span.array->rgba[i], clearColor);
  69       }
  70    }
  71    else if (span.array->ChanType == GL_UNSIGNED_SHORT) {
  72       GLushort clearColor[4];
  73       UNCLAMPED_FLOAT_TO_USHORT(clearColor[RCOMP], ctx->Color.ClearColor[0]);
  74       UNCLAMPED_FLOAT_TO_USHORT(clearColor[GCOMP], ctx->Color.ClearColor[1]);
  75       UNCLAMPED_FLOAT_TO_USHORT(clearColor[BCOMP], ctx->Color.ClearColor[2]);
  76       UNCLAMPED_FLOAT_TO_USHORT(clearColor[ACOMP], ctx->Color.ClearColor[3]);
  77       for (i = 0; i < width; i++) {
  78          COPY_4V_CAST(span.array->rgba[i], clearColor, GLchan);
  79       }
  80    }
  81    else {
  82       ASSERT(span.array->ChanType == GL_FLOAT);
  83       for (i = 0; i < width; i++) {
  84          CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][0], ctx->Color.ClearColor[0]);
  85          CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][1], ctx->Color.ClearColor[1]);
  86          CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][2], ctx->Color.ClearColor[2]);
  87          CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][3], ctx->Color.ClearColor[3]);
  88       }
  89    }
  90
  91    /* Note that masking will change the color values, but only the
  92     * channels for which the write mask is GL_FALSE.  The channels
  93     * which which are write-enabled won't get modified.
  94     */
  95    for (i = 0; i < height; i++) {
  96       span.x = x;
  97       span.y = y + i;
  98       _swrast_mask_rgba_span(ctx, rb, &span, buf);
  99       /* write masked row */
 100       rb->PutRow(ctx, rb, width, x, y + i, span.array->rgba, NULL);
 101    }
 102 }
 103
 104
 105 /**
 106  * Clear an rgba color buffer without channel masking.
 107  */
 108 static void
 109 clear_rgba_buffer(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint buf)
 110 {
 111    const GLint x = ctx->DrawBuffer->_Xmin;
 112    const GLint y = ctx->DrawBuffer->_Ymin;
 113    const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
 114    const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
 115    GLubyte clear8[4];
 116    GLushort clear16[4];
 117    GLvoid *clearVal;
 118    GLint i;
 119
 120    ASSERT(ctx->Color.ColorMask[buf][0] &&
 121           ctx->Color.ColorMask[buf][1] &&
 122           ctx->Color.ColorMask[buf][2] &&
 123           ctx->Color.ColorMask[buf][3]);
 124
 125    ASSERT(rb->PutMonoRow);
 126
 127    switch (rb->DataType) {
 128       case GL_UNSIGNED_BYTE:
 129          UNCLAMPED_FLOAT_TO_UBYTE(clear8[0], ctx->Color.ClearColor[0]);
 130          UNCLAMPED_FLOAT_TO_UBYTE(clear8[1], ctx->Color.ClearColor[1]);
 131          UNCLAMPED_FLOAT_TO_UBYTE(clear8[2], ctx->Color.ClearColor[2]);
 132          UNCLAMPED_FLOAT_TO_UBYTE(clear8[3], ctx->Color.ClearColor[3]);
 133          clearVal = clear8;
 134          break;
 135       case GL_UNSIGNED_SHORT:
 136          UNCLAMPED_FLOAT_TO_USHORT(clear16[0], ctx->Color.ClearColor[0]);
 137          UNCLAMPED_FLOAT_TO_USHORT(clear16[1], ctx->Color.ClearColor[1]);
 138          UNCLAMPED_FLOAT_TO_USHORT(clear16[2], ctx->Color.ClearColor[2]);
 139          UNCLAMPED_FLOAT_TO_USHORT(clear16[3], ctx->Color.ClearColor[3]);
 140          clearVal = clear16;
 141          break;
 142       case GL_FLOAT:
 143          clearVal = ctx->Color.ClearColor;
 144          break;
 145       default:
 146          _mesa_problem(ctx, "Bad rb DataType in clear_color_buffer");
 147          return;
 148    }
 149
 150    for (i = 0; i < height; i++) {
 151       rb->PutMonoRow(ctx, rb, width, x, y + i, clearVal, NULL);
 152    }
 153 }
 154
 155
 156 /**
 157  * Clear the front/back/left/right/aux color buffers.
 158  * This function is usually only called if the device driver can't
 159  * clear its own color buffers for some reason (such as with masking).
 160  */
 161 static void
 162 clear_color_buffers(GLcontext *ctx)
 163 {
 164    GLuint buf;
 165
 166    for (buf = 0; buf < ctx->DrawBuffer->_NumColorDrawBuffers; buf++) {
 167       struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[buf];
 168       if (ctx->Color.ColorMask[buf][0] == 0 ||
 169           ctx->Color.ColorMask[buf][1] == 0 ||
 170           ctx->Color.ColorMask[buf][2] == 0 ||
 171           ctx->Color.ColorMask[buf][3] == 0) {
 172          clear_rgba_buffer_with_masking(ctx, rb, buf);
 173       }
 174       else {
 175          clear_rgba_buffer(ctx, rb, buf);
 176       }
 177    }
 178 }
 179
 180
 181 /**
 182  * Called via the device driver's ctx->Driver.Clear() function if the
 183  * device driver can't clear one or more of the buffers itself.
 184  * \param buffers  bitfield of BUFFER_BIT_* values indicating which
 185  *                 renderbuffers are to be cleared.
 186  * \param all  if GL_TRUE, clear whole buffer, else clear specified region.
 187  */
 188 void
 189 _swrast_Clear(GLcontext *ctx, GLbitfield buffers)
 190 {
 191 #ifdef DEBUG_FOO
 192    {
 193       const GLbitfield legalBits =
 194          BUFFER_BIT_FRONT_LEFT |
 195          BUFFER_BIT_FRONT_RIGHT |
 196          BUFFER_BIT_BACK_LEFT |
 197          BUFFER_BIT_BACK_RIGHT |
 198          BUFFER_BIT_DEPTH |
 199          BUFFER_BIT_STENCIL |
 200          BUFFER_BIT_ACCUM |
 201          BUFFER_BIT_AUX0;
 202       assert((buffers & (~legalBits)) == 0);
 203    }
 204 #endif
 205
 206    if (!_mesa_check_conditional_render(ctx))
 207       return; /* don't clear */
 208
 209    swrast_render_start(ctx);
 210
 211    /* do software clearing here */
 212    if (buffers) {
 213       if ((buffers & BUFFER_BITS_COLOR)
 214           && (ctx->DrawBuffer->_NumColorDrawBuffers > 0)) {
 215          clear_color_buffers(ctx);
 216       }
 217       if (buffers & BUFFER_BIT_DEPTH) {
 218          _swrast_clear_depth_buffer(ctx, ctx->DrawBuffer->_DepthBuffer);
 219       }
 220       if (buffers & BUFFER_BIT_ACCUM) {
 221          _swrast_clear_accum_buffer(ctx,
 222                        ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer);
 223       }
 224       if (buffers & BUFFER_BIT_STENCIL) {
 225          _swrast_clear_stencil_buffer(ctx, ctx->DrawBuffer->_StencilBuffer);
 226       }
 227    }
 228
 229    swrast_render_finish(ctx);
 230 }