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/formats.h"
  29 #include "main/macros.h"
  30 #include "main/imports.h"
  31 #include "main/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                                GLuint buf)
  46 {
  47    const GLint x = ctx->DrawBuffer->_Xmin;
  48    const GLint y = ctx->DrawBuffer->_Ymin;
  49    const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
  50    const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
  51    SWspan span;
  52    GLint i;
  53
  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);
  59    span.end = width;
  60    span.arrayMask = SPAN_RGBA;
  61    span.array->ChanType = rb->DataType;
  62    if (span.array->ChanType == GL_UNSIGNED_BYTE) {
  63       GLubyte clearColor[4];
  64       UNCLAMPED_FLOAT_TO_UBYTE(clearColor[RCOMP], ctx->Color.ClearColor[0]);
  65       UNCLAMPED_FLOAT_TO_UBYTE(clearColor[GCOMP], ctx->Color.ClearColor[1]);
  66       UNCLAMPED_FLOAT_TO_UBYTE(clearColor[BCOMP], ctx->Color.ClearColor[2]);
  67       UNCLAMPED_FLOAT_TO_UBYTE(clearColor[ACOMP], ctx->Color.ClearColor[3]);
  68       for (i = 0; i < width; i++) {
  69          COPY_4UBV(span.array->rgba[i], clearColor);
  70       }
  71    }
  72    else if (span.array->ChanType == GL_UNSIGNED_SHORT) {
  73       GLushort clearColor[4];
  74       UNCLAMPED_FLOAT_TO_USHORT(clearColor[RCOMP], ctx->Color.ClearColor[0]);
  75       UNCLAMPED_FLOAT_TO_USHORT(clearColor[GCOMP], ctx->Color.ClearColor[1]);
  76       UNCLAMPED_FLOAT_TO_USHORT(clearColor[BCOMP], ctx->Color.ClearColor[2]);
  77       UNCLAMPED_FLOAT_TO_USHORT(clearColor[ACOMP], ctx->Color.ClearColor[3]);
  78       for (i = 0; i < width; i++) {
  79          COPY_4V_CAST(span.array->rgba[i], clearColor, GLchan);
  80       }
  81    }
  82    else {
  83       ASSERT(span.array->ChanType == GL_FLOAT);
  84       for (i = 0; i < width; i++) {
  85          CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][0], ctx->Color.ClearColor[0]);
  86          CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][1], ctx->Color.ClearColor[1]);
  87          CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][2], ctx->Color.ClearColor[2]);
  88          CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][3], ctx->Color.ClearColor[3]);
  89       }
  90    }
  91
  92    /* Note that masking will change the color values, but only the
  93     * channels for which the write mask is GL_FALSE.  The channels
  94     * which which are write-enabled won't get modified.
  95     */
  96    for (i = 0; i < height; i++) {
  97       span.x = x;
  98       span.y = y + i;
  99       _swrast_mask_rgba_span(ctx, rb, &span, buf);
 100       /* write masked row */
 101       rb->PutRow(ctx, rb, width, x, y + i, span.array->rgba, NULL);
 102    }
 103 }
 104
 105
 106 /**
 107  * Clear an rgba color buffer without channel masking.
 108  */
 109 static void
 110 clear_rgba_buffer(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint buf)
 111 {
 112    const GLint x = ctx->DrawBuffer->_Xmin;
 113    const GLint y = ctx->DrawBuffer->_Ymin;
 114    const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
 115    const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
 116    GLubyte clear8[4];
 117    GLushort clear16[4];
 118    GLvoid *clearVal;
 119    GLint i;
 120
 121    ASSERT(ctx->Color.ColorMask[buf][0] &&
 122           ctx->Color.ColorMask[buf][1] &&
 123           ctx->Color.ColorMask[buf][2] &&
 124           ctx->Color.ColorMask[buf][3]);
 125
 126    ASSERT(rb->PutMonoRow);
 127
 128    switch (rb->DataType) {
 129       case GL_UNSIGNED_BYTE:
 130          UNCLAMPED_FLOAT_TO_UBYTE(clear8[0], ctx->Color.ClearColor[0]);
 131          UNCLAMPED_FLOAT_TO_UBYTE(clear8[1], ctx->Color.ClearColor[1]);
 132          UNCLAMPED_FLOAT_TO_UBYTE(clear8[2], ctx->Color.ClearColor[2]);
 133          UNCLAMPED_FLOAT_TO_UBYTE(clear8[3], ctx->Color.ClearColor[3]);
 134          clearVal = clear8;
 135          break;
 136       case GL_UNSIGNED_SHORT:
 137          UNCLAMPED_FLOAT_TO_USHORT(clear16[0], ctx->Color.ClearColor[0]);
 138          UNCLAMPED_FLOAT_TO_USHORT(clear16[1], ctx->Color.ClearColor[1]);
 139          UNCLAMPED_FLOAT_TO_USHORT(clear16[2], ctx->Color.ClearColor[2]);
 140          UNCLAMPED_FLOAT_TO_USHORT(clear16[3], ctx->Color.ClearColor[3]);
 141          clearVal = clear16;
 142          break;
 143       case GL_FLOAT:
 144          clearVal = ctx->Color.ClearColor;
 145          break;
 146       default:
 147          _mesa_problem(ctx, "Bad rb DataType in clear_color_buffer");
 148          return;
 149    }
 150
 151    for (i = 0; i < height; i++) {
 152       rb->PutMonoRow(ctx, rb, width, x, y + i, clearVal, NULL);
 153    }
 154 }
 155
 156
 157 /**
 158  * Clear the front/back/left/right/aux color buffers.
 159  * This function is usually only called if the device driver can't
 160  * clear its own color buffers for some reason (such as with masking).
 161  */
 162 static void
 163 clear_color_buffers(GLcontext *ctx)
 164 {
 165    GLuint buf;
 166
 167    for (buf = 0; buf < ctx->DrawBuffer->_NumColorDrawBuffers; buf++) {
 168       struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[buf];
 169       if (ctx->Color.ColorMask[buf][0] == 0 ||
 170           ctx->Color.ColorMask[buf][1] == 0 ||
 171           ctx->Color.ColorMask[buf][2] == 0 ||
 172           ctx->Color.ColorMask[buf][3] == 0) {
 173          clear_rgba_buffer_with_masking(ctx, rb, buf);
 174       }
 175       else {
 176          clear_rgba_buffer(ctx, rb, buf);
 177       }
 178    }
 179 }
 180
 181
 182 /**
 183  * Called via the device driver's ctx->Driver.Clear() function if the
 184  * device driver can't clear one or more of the buffers itself.
 185  * \param buffers  bitfield of BUFFER_BIT_* values indicating which
 186  *                 renderbuffers are to be cleared.
 187  * \param all  if GL_TRUE, clear whole buffer, else clear specified region.
 188  */
 189 void
 190 _swrast_Clear(GLcontext *ctx, GLbitfield buffers)
 191 {
 192 #ifdef DEBUG_FOO
 193    {
 194       const GLbitfield legalBits =
 195          BUFFER_BIT_FRONT_LEFT |
 196          BUFFER_BIT_FRONT_RIGHT |
 197          BUFFER_BIT_BACK_LEFT |
 198          BUFFER_BIT_BACK_RIGHT |
 199          BUFFER_BIT_DEPTH |
 200          BUFFER_BIT_STENCIL |
 201          BUFFER_BIT_ACCUM |
 202          BUFFER_BIT_AUX0;
 203       assert((buffers & (~legalBits)) == 0);
 204    }
 205 #endif
 206
 207    if (!_mesa_check_conditional_render(ctx))
 208       return; /* don't clear */
 209
 210    swrast_render_start(ctx);
 211
 212    /* do software clearing here */
 213    if (buffers) {
 214       if ((buffers & BUFFER_BITS_COLOR)
 215           && (ctx->DrawBuffer->_NumColorDrawBuffers > 0)) {
 216          clear_color_buffers(ctx);
 217       }
 218       if (buffers & BUFFER_BIT_DEPTH) {
 219          _swrast_clear_depth_buffer(ctx, ctx->DrawBuffer->_DepthBuffer);
 220       }
 221       if (buffers & BUFFER_BIT_ACCUM) {
 222          _swrast_clear_accum_buffer(ctx,
 223                        ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer);
 224       }
 225       if (buffers & BUFFER_BIT_STENCIL) {
 226          _swrast_clear_stencil_buffer(ctx, ctx->DrawBuffer->_StencilBuffer);
 227       }
 228    }
 229
 230    swrast_render_finish(ctx);
 231 }