src/mesa/swrast/s_buffers.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.3
   4  *
   5  * Copyright (C) 1999-2004  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
  26 #include "glheader.h"
  27 #include "colormac.h"
  28 #include "macros.h"
  29 #include "imports.h"
  30
  31 #include "s_accum.h"
  32 #include "s_alphabuf.h"
  33 #include "s_auxbuffer.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 or glIndexMask is in effect.
  42  * We'll have specified which color buffer to clear by previously
  43  * calling Driver.SetBuffer().
  44  */
  45 static void
  46 clear_color_buffer_with_masking( GLcontext *ctx )
  47 {
  48    SWcontext *swrast = SWRAST_CONTEXT(ctx);
  49    const GLint x = ctx->DrawBuffer->_Xmin;
  50    const GLint y = ctx->DrawBuffer->_Ymin;
  51    const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
  52    const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
  53
  54    if (ctx->Visual.rgbMode) {
  55       /* RGBA mode */
  56       GLchan clearColor[4];
  57       GLint i;
  58       CLAMPED_FLOAT_TO_CHAN(clearColor[RCOMP], ctx->Color.ClearColor[0]);
  59       CLAMPED_FLOAT_TO_CHAN(clearColor[GCOMP], ctx->Color.ClearColor[1]);
  60       CLAMPED_FLOAT_TO_CHAN(clearColor[BCOMP], ctx->Color.ClearColor[2]);
  61       CLAMPED_FLOAT_TO_CHAN(clearColor[ACOMP], ctx->Color.ClearColor[3]);
  62       for (i = 0; i < height; i++) {
  63          GLchan rgba[MAX_WIDTH][4];
  64          GLint j;
  65          for (j = 0; j < width; j++) {
  66             COPY_CHAN4(rgba[j], clearColor);
  67          }
  68          _swrast_mask_rgba_array( ctx, width, x, y + i, rgba );
  69          (*swrast->Driver.WriteRGBASpan)( ctx, width, x, y + i,
  70                                           (CONST GLchan (*)[4]) rgba, NULL );
  71       }
  72    }
  73    else {
  74       /* Color index mode */
  75       GLuint span[MAX_WIDTH];
  76       GLubyte mask[MAX_WIDTH];
  77       GLint i, j;
  78       MEMSET( mask, 1, width );
  79       for (i=0;i<height;i++) {
  80          for (j=0;j<width;j++) {
  81             span[j] = ctx->Color.ClearIndex;
  82          }
  83          _swrast_mask_index_array( ctx, width, x, y + i, span );
  84          (*swrast->Driver.WriteCI32Span)( ctx, width, x, y + i, span, mask );
  85       }
  86    }
  87 }
  88
  89
  90 /**
  91  * Clear a color buffer without index/channel masking.
  92  * We'll have specified which color buffer to clear by previously
  93  * calling Driver.SetBuffer().
  94  */
  95 static void
  96 clear_color_buffer(GLcontext *ctx)
  97 {
  98    SWcontext *swrast = SWRAST_CONTEXT(ctx);
  99    const GLint x = ctx->DrawBuffer->_Xmin;
 100    const GLint y = ctx->DrawBuffer->_Ymin;
 101    const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
 102    const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
 103
 104    if (ctx->Visual.rgbMode) {
 105       /* RGBA mode */
 106       GLchan clearColor[4];
 107       GLint i;
 108
 109       CLAMPED_FLOAT_TO_CHAN(clearColor[RCOMP], ctx->Color.ClearColor[0]);
 110       CLAMPED_FLOAT_TO_CHAN(clearColor[GCOMP], ctx->Color.ClearColor[1]);
 111       CLAMPED_FLOAT_TO_CHAN(clearColor[BCOMP], ctx->Color.ClearColor[2]);
 112       CLAMPED_FLOAT_TO_CHAN(clearColor[ACOMP], ctx->Color.ClearColor[3]);
 113
 114       ASSERT(*((GLuint *) &ctx->Color.ColorMask) == 0xffffffff);
 115       ASSERT(swrast->Driver.WriteRGBASpan);
 116
 117       for (i = 0; i < height; i++) {
 118          (*swrast->Driver.WriteMonoRGBASpan)( ctx, width, x, y + i,
 119                                               clearColor, NULL );
 120       }
 121    }
 122    else {
 123       /* Color index mode */
 124       GLint i;
 125       ASSERT((ctx->Color.IndexMask & ((1 << ctx->Visual.indexBits) - 1))
 126              == (GLuint) ((1 << ctx->Visual.indexBits) - 1));
 127       ASSERT(swrast->Driver.WriteMonoCISpan);
 128       for (i = 0; i < height; i++) {
 129          (*swrast->Driver.WriteMonoCISpan)( ctx, width, x, y + i,
 130                                             ctx->Color.ClearIndex, NULL);
 131       }
 132    }
 133 }
 134
 135
 136 /**
 137  * Clear the front/back/left/right/aux color buffers.
 138  * This function is usually only called if the device driver can't
 139  * clear its own color buffers for some reason (such as with masking).
 140  */
 141 static void
 142 clear_color_buffers(GLcontext *ctx)
 143 {
 144    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 145    const GLuint colorMask = *((GLuint *) &ctx->Color.ColorMask);
 146    GLuint bufferBit;
 147
 148    /* loop over four possible dest color buffers */
 149    for (bufferBit = 1; bufferBit <= DD_AUX3_BIT; bufferBit <<= 1) {
 150       if (bufferBit & ctx->Color._DrawDestMask[0]) {
 151          (*swrast->Driver.SetBuffer)(ctx, ctx->DrawBuffer, bufferBit);
 152
 153          if (colorMask != 0xffffffff) {
 154             clear_color_buffer_with_masking(ctx);
 155          }
 156          else {
 157             clear_color_buffer(ctx);
 158          }
 159       }
 160    }
 161
 162    /* restore default read/draw buffer */
 163    _swrast_use_draw_buffer(ctx);
 164 }
 165
 166
 167 /**
 168  * Called via the device driver's ctx->Driver.Clear() function if the
 169  * device driver can't clear one or more of the buffers itself.
 170  * \param mask  bitwise-OR of DD_*_BIT flags.
 171  * \param all  if GL_TRUE, clear whole buffer, else clear specified region.
 172  */
 173 void
 174 _swrast_Clear( GLcontext *ctx, GLbitfield mask,
 175                GLboolean all,
 176                GLint x, GLint y, GLint width, GLint height )
 177 {
 178    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 179    (void) all; (void) x; (void) y; (void) width; (void) height;
 180 #ifdef DEBUG
 181    {
 182       const GLbitfield legalBits =
 183          DD_FRONT_LEFT_BIT |
 184          DD_FRONT_RIGHT_BIT |
 185          DD_BACK_LEFT_BIT |
 186          DD_BACK_RIGHT_BIT |
 187          DD_DEPTH_BIT |
 188          DD_STENCIL_BIT |
 189          DD_ACCUM_BIT |
 190          DD_AUX0_BIT |
 191          DD_AUX1_BIT |
 192          DD_AUX2_BIT |
 193          DD_AUX3_BIT;
 194       assert((mask & (~legalBits)) == 0);
 195    }
 196 #endif
 197
 198    RENDER_START(swrast,ctx);
 199
 200    /* do software clearing here */
 201    if (mask) {
 202       if (mask & ctx->Color._DrawDestMask[0]) {
 203          clear_color_buffers(ctx);
 204          /* clear software-based alpha buffer(s) */
 205          if (ctx->DrawBuffer->UseSoftwareAlphaBuffers
 206              && ctx->Color.ColorMask[ACOMP]) {
 207             _swrast_clear_alpha_buffers( ctx );
 208          }
 209       }
 210       if (mask & DD_DEPTH_BIT) {
 211          _swrast_clear_depth_buffer(ctx);
 212       }
 213       if (mask & DD_ACCUM_BIT) {
 214          _swrast_clear_accum_buffer(ctx);
 215       }
 216       if (mask & DD_STENCIL_BIT) {
 217          _swrast_clear_stencil_buffer(ctx);
 218       }
 219    }
 220
 221    RENDER_FINISH(swrast,ctx);
 222 }
 223
 224
 225 /**
 226  * Typically called via ctx->Driver.ResizeBuffers().
 227  * Reallocate all software-based depth/stencil/accum/etc buffers
 228  * to match current window dimensions.
 229  */
 230 void
 231 _swrast_alloc_buffers( GLframebuffer *buffer )
 232 {
 233    /* Reallocate other buffers if needed. */
 234    if (buffer->UseSoftwareDepthBuffer) {
 235       _swrast_alloc_depth_buffer( buffer );
 236    }
 237    if (buffer->UseSoftwareStencilBuffer) {
 238       _swrast_alloc_stencil_buffer( buffer );
 239    }
 240    if (buffer->UseSoftwareAccumBuffer) {
 241       _swrast_alloc_accum_buffer( buffer );
 242    }
 243    if (buffer->UseSoftwareAlphaBuffers) {
 244       _swrast_alloc_alpha_buffers( buffer );
 245    }
 246    if (buffer->UseSoftwareAuxBuffers) {
 247       _swrast_alloc_aux_buffers( buffer );
 248    }
 249 }
 250
 251
 252 /*
 253  * Fallback for ctx->Driver.DrawBuffer()
 254  */
 255 void
 256 _swrast_DrawBuffer( GLcontext *ctx, GLenum mode )
 257 {
 258    (void) mode;
 259    _swrast_use_draw_buffer(ctx);
 260 }
 261
 262
 263 /*
 264  * Fallback for ctx->Driver.DrawBuffers()
 265  */
 266 void
 267 _swrast_DrawBuffers( GLcontext *ctx, GLsizei n, const GLenum *buffers )
 268 {
 269    _swrast_use_draw_buffer(ctx);
 270 }
 271
 272
 273 /*
 274  * Setup things so that we read/write spans from the user-designated
 275  * read buffer (set via glReadPixels).  We usually just have to call
 276  * this for glReadPixels, glCopyPixels, etc.
 277  */
 278 void
 279 _swrast_use_read_buffer( GLcontext *ctx )
 280 {
 281    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 282
 283    /* Do this so the software-emulated alpha plane span functions work! */
 284    swrast->CurrentBufferBit = ctx->Pixel._ReadSrcMask;
 285    /* Tell the device driver where to read/write spans */
 286    swrast->Driver.SetBuffer(ctx, ctx->ReadBuffer, swrast->CurrentBufferBit);
 287 }
 288
 289
 290 /*
 291  * Setup things so that we read/write spans from the default draw buffer.
 292  * This is the usual mode that Mesa's software rasterizer operates in.
 293  */
 294 void
 295 _swrast_use_draw_buffer( GLcontext *ctx )
 296 {
 297    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 298
 299    /* The user can specify rendering to zero, one, two, or four color
 300     * buffers simultaneously with glDrawBuffer()!
 301     * We don't expect the span/point/line/triangle functions to deal with
 302     * that mess so we'll iterate over the multiple buffers as needed.
 303     * But usually we only render to one color buffer at a time.
 304     * We set ctx->Color._DriverDrawBuffer to that buffer and tell the
 305     * device driver to use that buffer.
 306     * Look in s_span.c's multi_write_rgba_span() function to see how
 307     * we loop over multiple color buffers when needed.
 308     */
 309
 310    if (ctx->Color._DrawDestMask[0] & DD_FRONT_LEFT_BIT)
 311       swrast->CurrentBufferBit = DD_FRONT_LEFT_BIT;
 312    else if (ctx->Color._DrawDestMask[0] & DD_BACK_LEFT_BIT)
 313       swrast->CurrentBufferBit = DD_BACK_LEFT_BIT;
 314    else if (ctx->Color._DrawDestMask[0] & DD_FRONT_RIGHT_BIT)
 315       swrast->CurrentBufferBit = DD_FRONT_RIGHT_BIT;
 316    else if (ctx->Color._DrawDestMask[0] & DD_BACK_RIGHT_BIT)
 317       swrast->CurrentBufferBit = DD_BACK_RIGHT_BIT;
 318    else if (ctx->Color._DrawDestMask[0] & DD_AUX0_BIT)
 319       swrast->CurrentBufferBit = DD_AUX0_BIT;
 320    else if (ctx->Color._DrawDestMask[0] & DD_AUX1_BIT)
 321       swrast->CurrentBufferBit = DD_AUX1_BIT;
 322    else if (ctx->Color._DrawDestMask[0] & DD_AUX2_BIT)
 323       swrast->CurrentBufferBit = DD_AUX2_BIT;
 324    else if (ctx->Color._DrawDestMask[0] & DD_AUX3_BIT)
 325       swrast->CurrentBufferBit = DD_AUX3_BIT;
 326    else
 327       /* glDrawBuffer(GL_NONE) */
 328       swrast->CurrentBufferBit = DD_FRONT_LEFT_BIT; /* we always have this buffer */
 329
 330    swrast->Driver.SetBuffer(ctx, ctx->DrawBuffer, swrast->CurrentBufferBit);
 331 }