src/mesa/swrast/s_buffers.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.2
   4  *
   5  * Copyright (C) 1999-2006  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 /** XXX This file should be named s_clear.c */
  26
  27 #include "glheader.h"
  28 #include "colormac.h"
  29 #include "macros.h"
  30 #include "imports.h"
  31 #include "mtypes.h"
  32
  33 #include "s_accum.h"
  34 #include "s_context.h"
  35 #include "s_depth.h"
  36 #include "s_masking.h"
  37 #include "s_stencil.h"
  38
  39
  40 /**
  41  * Clear the color buffer when glColorMask is in effect.
  42  */
  43 static void
  44 clear_rgba_buffer_with_masking(GLcontext *ctx, struct gl_renderbuffer *rb)
  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(ctx->Visual.rgbMode);
  54    ASSERT(rb->PutRow);
  55
  56    /* Initialize color span with clear color */
  57    /* XXX optimize for clearcolor == black/zero (bzero) */
  58    INIT_SPAN(span, GL_BITMAP, width, 0, SPAN_RGBA);
  59    span.array->ChanType = rb->DataType;
  60    if (span.array->ChanType == GL_UNSIGNED_BYTE) {
  61       GLubyte clearColor[4];
  62       UNCLAMPED_FLOAT_TO_UBYTE(clearColor[RCOMP], ctx->Color.ClearColor[0]);
  63       UNCLAMPED_FLOAT_TO_UBYTE(clearColor[GCOMP], ctx->Color.ClearColor[1]);
  64       UNCLAMPED_FLOAT_TO_UBYTE(clearColor[BCOMP], ctx->Color.ClearColor[2]);
  65       UNCLAMPED_FLOAT_TO_UBYTE(clearColor[ACOMP], ctx->Color.ClearColor[3]);
  66       for (i = 0; i < width; i++) {
  67          COPY_4UBV(span.array->rgba[i], clearColor);
  68       }
  69    }
  70    else if (span.array->ChanType == GL_UNSIGNED_SHORT) {
  71       GLushort clearColor[4];
  72       UNCLAMPED_FLOAT_TO_USHORT(clearColor[RCOMP], ctx->Color.ClearColor[0]);
  73       UNCLAMPED_FLOAT_TO_USHORT(clearColor[GCOMP], ctx->Color.ClearColor[1]);
  74       UNCLAMPED_FLOAT_TO_USHORT(clearColor[BCOMP], ctx->Color.ClearColor[2]);
  75       UNCLAMPED_FLOAT_TO_USHORT(clearColor[ACOMP], ctx->Color.ClearColor[3]);
  76       for (i = 0; i < width; i++) {
  77          COPY_4V(span.array->rgba[i], clearColor);
  78       }
  79    }
  80    else {
  81       ASSERT(span.array->ChanType == GL_FLOAT);
  82       for (i = 0; i < width; i++) {
  83          CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][0], ctx->Color.ClearColor[0]);
  84          CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][1], ctx->Color.ClearColor[1]);
  85          CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][2], ctx->Color.ClearColor[2]);
  86          CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][3], ctx->Color.ClearColor[3]);
  87       }
  88    }
  89
  90    /* Note that masking will change the color values, but only the
  91     * channels for which the write mask is GL_FALSE.  The channels
  92     * which which are write-enabled won't get modified.
  93     */
  94    for (i = 0; i < height; i++) {
  95       span.x = x;
  96       span.y = y + i;
  97       _swrast_mask_rgba_span(ctx, rb, &span);
  98       /* write masked row */
  99       rb->PutRow(ctx, rb, width, x, y + i, span.array->rgba, NULL);
 100    }
 101 }
 102
 103
 104 /**
 105  * Clear color index buffer with masking.
 106  */
 107 static void
 108 clear_ci_buffer_with_masking(GLcontext *ctx, struct gl_renderbuffer *rb)
 109 {
 110    const GLint x = ctx->DrawBuffer->_Xmin;
 111    const GLint y = ctx->DrawBuffer->_Ymin;
 112    const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
 113    const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
 114    SWspan span;
 115    GLint i;
 116
 117    ASSERT(!ctx->Visual.rgbMode);
 118    ASSERT(rb->PutRow);
 119    ASSERT(rb->DataType == GL_UNSIGNED_INT);
 120
 121    /* Initialize index span with clear index */
 122    INIT_SPAN(span, GL_BITMAP, width, 0, SPAN_RGBA);
 123    for (i = 0; i < width;i++) {
 124       span.array->index[i] = ctx->Color.ClearIndex;
 125    }
 126
 127    /* Note that masking will change the color indexes, but only the
 128     * bits for which the write mask is GL_FALSE.  The bits
 129     * which are write-enabled won't get modified.
 130     */
 131    for (i = 0; i < height;i++) {
 132       span.x = x;
 133       span.y = y + i;
 134       _swrast_mask_ci_span(ctx, rb, &span);
 135       /* write masked row */
 136       rb->PutRow(ctx, rb, width, x, y + i, span.array->index, NULL);
 137    }
 138 }
 139
 140
 141 /**
 142  * Clear an rgba color buffer without channel masking.
 143  */
 144 static void
 145 clear_rgba_buffer(GLcontext *ctx, struct gl_renderbuffer *rb)
 146 {
 147    const GLint x = ctx->DrawBuffer->_Xmin;
 148    const GLint y = ctx->DrawBuffer->_Ymin;
 149    const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
 150    const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
 151    GLubyte clear8[4];
 152    GLushort clear16[4];
 153    GLvoid *clearVal;
 154    GLint i;
 155
 156    ASSERT(ctx->Visual.rgbMode);
 157
 158    ASSERT(ctx->Color.ColorMask[0] &&
 159           ctx->Color.ColorMask[1] &&
 160           ctx->Color.ColorMask[2] &&
 161           ctx->Color.ColorMask[3]);
 162
 163    ASSERT(rb->PutMonoRow);
 164
 165    switch (rb->DataType) {
 166       case GL_UNSIGNED_BYTE:
 167          UNCLAMPED_FLOAT_TO_UBYTE(clear8[0], ctx->Color.ClearColor[0]);
 168          UNCLAMPED_FLOAT_TO_UBYTE(clear8[1], ctx->Color.ClearColor[1]);
 169          UNCLAMPED_FLOAT_TO_UBYTE(clear8[2], ctx->Color.ClearColor[2]);
 170          UNCLAMPED_FLOAT_TO_UBYTE(clear8[3], ctx->Color.ClearColor[3]);
 171          clearVal = clear8;
 172          break;
 173       case GL_UNSIGNED_SHORT:
 174          UNCLAMPED_FLOAT_TO_USHORT(clear16[0], ctx->Color.ClearColor[0]);
 175          UNCLAMPED_FLOAT_TO_USHORT(clear16[1], ctx->Color.ClearColor[1]);
 176          UNCLAMPED_FLOAT_TO_USHORT(clear16[2], ctx->Color.ClearColor[2]);
 177          UNCLAMPED_FLOAT_TO_USHORT(clear16[3], ctx->Color.ClearColor[3]);
 178          clearVal = clear16;
 179          break;
 180       case GL_FLOAT:
 181          clearVal = ctx->Color.ClearColor;
 182          break;
 183       default:
 184          _mesa_problem(ctx, "Bad rb DataType in clear_color_buffer");
 185          return;
 186    }
 187
 188    for (i = 0; i < height; i++) {
 189       rb->PutMonoRow(ctx, rb, width, x, y + i, clearVal, NULL);
 190    }
 191 }
 192
 193
 194 /**
 195  * Clear color index buffer without masking.
 196  */
 197 static void
 198 clear_ci_buffer(GLcontext *ctx, struct gl_renderbuffer *rb)
 199 {
 200    const GLint x = ctx->DrawBuffer->_Xmin;
 201    const GLint y = ctx->DrawBuffer->_Ymin;
 202    const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
 203    const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
 204    GLubyte clear8;
 205    GLushort clear16;
 206    GLuint clear32;
 207    GLvoid *clearVal;
 208    GLint i;
 209
 210    ASSERT(!ctx->Visual.rgbMode);
 211
 212    ASSERT((ctx->Color.IndexMask & ((1 << rb->IndexBits) - 1))
 213           == (GLuint) ((1 << rb->IndexBits) - 1));
 214
 215    ASSERT(rb->PutMonoRow);
 216
 217    /* setup clear value */
 218    switch (rb->DataType) {
 219       case GL_UNSIGNED_BYTE:
 220          clear8 = (GLubyte) ctx->Color.ClearIndex;
 221          clearVal = &clear8;
 222          break;
 223       case GL_UNSIGNED_SHORT:
 224          clear16 = (GLushort) ctx->Color.ClearIndex;
 225          clearVal = &clear16;
 226          break;
 227       case GL_UNSIGNED_INT:
 228          clear32 = ctx->Color.ClearIndex;
 229          clearVal = &clear32;
 230          break;
 231       default:
 232          _mesa_problem(ctx, "Bad rb DataType in clear_color_buffer");
 233          return;
 234    }
 235
 236    for (i = 0; i < height; i++)
 237       rb->PutMonoRow(ctx, rb, width, x, y + i, clearVal, NULL);
 238 }
 239
 240
 241 /**
 242  * Clear the front/back/left/right/aux color buffers.
 243  * This function is usually only called if the device driver can't
 244  * clear its own color buffers for some reason (such as with masking).
 245  */
 246 static void
 247 clear_color_buffers(GLcontext *ctx)
 248 {
 249    GLboolean masking;
 250    GLuint i;
 251
 252    if (ctx->Visual.rgbMode) {
 253       if (ctx->Color.ColorMask[0] &&
 254           ctx->Color.ColorMask[1] &&
 255           ctx->Color.ColorMask[2] &&
 256           ctx->Color.ColorMask[3]) {
 257          masking = GL_FALSE;
 258       }
 259       else {
 260          masking = GL_TRUE;
 261       }
 262    }
 263    else {
 264       struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0][0];
 265       const GLuint indexBits = (1 << rb->IndexBits) - 1;
 266       if ((ctx->Color.IndexMask & indexBits) == indexBits) {
 267          masking = GL_FALSE;
 268       }
 269       else {
 270          masking = GL_TRUE;
 271       }
 272    }
 273
 274    for (i = 0; i < ctx->DrawBuffer->_NumColorDrawBuffers[0]; i++) {
 275       struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0][i];
 276       if (ctx->Visual.rgbMode) {
 277          if (masking) {
 278             clear_rgba_buffer_with_masking(ctx, rb);
 279          }
 280          else {
 281             clear_rgba_buffer(ctx, rb);
 282          }
 283       }
 284       else {
 285          if (masking) {
 286             clear_ci_buffer_with_masking(ctx, rb);
 287          }
 288          else {
 289             clear_ci_buffer(ctx, rb);
 290          }
 291       }
 292    }
 293 }
 294
 295
 296 /**
 297  * Called via the device driver's ctx->Driver.Clear() function if the
 298  * device driver can't clear one or more of the buffers itself.
 299  * \param buffers  bitfield of BUFFER_BIT_* values indicating which
 300  *                 renderbuffers are to be cleared.
 301  * \param all  if GL_TRUE, clear whole buffer, else clear specified region.
 302  */
 303 void
 304 _swrast_Clear(GLcontext *ctx, GLbitfield buffers)
 305 {
 306    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 307
 308 #ifdef DEBUG_FOO
 309    {
 310       const GLbitfield legalBits =
 311          BUFFER_BIT_FRONT_LEFT |
 312          BUFFER_BIT_FRONT_RIGHT |
 313          BUFFER_BIT_BACK_LEFT |
 314          BUFFER_BIT_BACK_RIGHT |
 315          BUFFER_BIT_DEPTH |
 316          BUFFER_BIT_STENCIL |
 317          BUFFER_BIT_ACCUM |
 318          BUFFER_BIT_AUX0 |
 319          BUFFER_BIT_AUX1 |
 320          BUFFER_BIT_AUX2 |
 321          BUFFER_BIT_AUX3;
 322       assert((buffers & (~legalBits)) == 0);
 323    }
 324 #endif
 325
 326    RENDER_START(swrast,ctx);
 327
 328    /* do software clearing here */
 329    if (buffers) {
 330       if (buffers & ctx->DrawBuffer->_ColorDrawBufferMask[0]) {
 331          clear_color_buffers(ctx);
 332       }
 333       if (buffers & BUFFER_BIT_DEPTH) {
 334          _swrast_clear_depth_buffer(ctx, ctx->DrawBuffer->_DepthBuffer);
 335       }
 336       if (buffers & BUFFER_BIT_ACCUM) {
 337          _swrast_clear_accum_buffer(ctx,
 338                        ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer);
 339       }
 340       if (buffers & BUFFER_BIT_STENCIL) {
 341          _swrast_clear_stencil_buffer(ctx, ctx->DrawBuffer->_StencilBuffer);
 342       }
 343    }
 344
 345    RENDER_FINISH(swrast,ctx);
 346 }