src/mesa/main/clear.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.1
   4  *
   5  * Copyright (C) 1999-2007  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 /**
  27  * \file clear.c
  28  * glClearColor, glClearIndex, glClear() functions.
  29  */
  30
  31
  32
  33 #include "glheader.h"
  34 #include "clear.h"
  35 #include "context.h"
  36 #include "colormac.h"
  37 #include "state.h"
  38
  39
  40
  41 #if _HAVE_FULL_GL
  42 void GLAPIENTRY
  43 _mesa_ClearIndex( GLfloat c )
  44 {
  45    GET_CURRENT_CONTEXT(ctx);
  46    ASSERT_OUTSIDE_BEGIN_END(ctx);
  47
  48    if (ctx->Color.ClearIndex == (GLuint) c)
  49       return;
  50
  51    FLUSH_VERTICES(ctx, _NEW_COLOR);
  52    ctx->Color.ClearIndex = (GLuint) c;
  53
  54    if (!ctx->Visual.rgbMode && ctx->Driver.ClearIndex) {
  55       /* it's OK to call glClearIndex in RGBA mode but it should be a NOP */
  56       (*ctx->Driver.ClearIndex)( ctx, ctx->Color.ClearIndex );
  57    }
  58 }
  59 #endif
  60
  61
  62 /**
  63  * Specify the clear values for the color buffers.
  64  *
  65  * \param red red color component.
  66  * \param green green color component.
  67  * \param blue blue color component.
  68  * \param alpha alpha component.
  69  *
  70  * \sa glClearColor().
  71  *
  72  * Clamps the parameters and updates gl_colorbuffer_attrib::ClearColor.  On a
  73  * change, flushes the vertices and notifies the driver via the
  74  * dd_function_table::ClearColor callback.
  75  */
  76 void GLAPIENTRY
  77 _mesa_ClearColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha )
  78 {
  79    GLfloat tmp[4];
  80    GET_CURRENT_CONTEXT(ctx);
  81    ASSERT_OUTSIDE_BEGIN_END(ctx);
  82
  83    tmp[0] = CLAMP(red,   0.0F, 1.0F);
  84    tmp[1] = CLAMP(green, 0.0F, 1.0F);
  85    tmp[2] = CLAMP(blue,  0.0F, 1.0F);
  86    tmp[3] = CLAMP(alpha, 0.0F, 1.0F);
  87
  88    if (TEST_EQ_4V(tmp, ctx->Color.ClearColor))
  89       return; /* no change */
  90
  91    FLUSH_VERTICES(ctx, _NEW_COLOR);
  92    COPY_4V(ctx->Color.ClearColor, tmp);
  93
  94    if (ctx->Visual.rgbMode && ctx->Driver.ClearColor) {
  95       /* it's OK to call glClearColor in CI mode but it should be a NOP */
  96       (*ctx->Driver.ClearColor)(ctx, ctx->Color.ClearColor);
  97    }
  98 }
  99
 100
 101 /**
 102  * Clear buffers.
 103  *
 104  * \param mask bit-mask indicating the buffers to be cleared.
 105  *
 106  * Flushes the vertices and verifies the parameter. If __GLcontextRec::NewState
 107  * is set then calls _mesa_update_state() to update gl_frame_buffer::_Xmin,
 108  * etc. If the rasterization mode is set to GL_RENDER then requests the driver
 109  * to clear the buffers, via the dd_function_table::Clear callback.
 110  */
 111 void GLAPIENTRY
 112 _mesa_Clear( GLbitfield mask )
 113 {
 114    GET_CURRENT_CONTEXT(ctx);
 115    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
 116
 117    FLUSH_CURRENT(ctx, 0);
 118
 119    if (MESA_VERBOSE & VERBOSE_API)
 120       _mesa_debug(ctx, "glClear 0x%x\n", mask);
 121
 122    if (mask & ~(GL_COLOR_BUFFER_BIT |
 123                 GL_DEPTH_BUFFER_BIT |
 124                 GL_STENCIL_BUFFER_BIT |
 125                 GL_ACCUM_BUFFER_BIT)) {
 126       /* invalid bit set */
 127       _mesa_error( ctx, GL_INVALID_VALUE, "glClear(0x%x)", mask);
 128       return;
 129    }
 130
 131    if (ctx->NewState) {
 132       _mesa_update_state( ctx );        /* update _Xmin, etc */
 133    }
 134
 135    if (ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 136       _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
 137                   "glClear(incomplete framebuffer)");
 138       return;
 139    }
 140
 141    if (ctx->DrawBuffer->Width == 0 || ctx->DrawBuffer->Height == 0 ||
 142        ctx->DrawBuffer->_Xmin >= ctx->DrawBuffer->_Xmax ||
 143        ctx->DrawBuffer->_Ymin >= ctx->DrawBuffer->_Ymax)
 144       return;
 145
 146    if (ctx->RenderMode == GL_RENDER) {
 147       GLbitfield bufferMask;
 148
 149       /* don't clear depth buffer if depth writing disabled */
 150       if (!ctx->Depth.Mask)
 151          mask &= ~GL_DEPTH_BUFFER_BIT;
 152
 153       /* Build the bitmask to send to device driver's Clear function.
 154        * Note that the GL_COLOR_BUFFER_BIT flag will expand to 0, 1, 2 or 4
 155        * of the BUFFER_BIT_FRONT/BACK_LEFT/RIGHT flags, or one of the
 156        * BUFFER_BIT_COLORn flags.
 157        */
 158       bufferMask = 0;
 159       if (mask & GL_COLOR_BUFFER_BIT) {
 160          GLuint i;
 161          for (i = 0; i < ctx->DrawBuffer->_NumColorDrawBuffers; i++) {
 162             bufferMask |= (1 << ctx->DrawBuffer->_ColorDrawBufferIndexes[i]);
 163          }
 164       }
 165
 166       if ((mask & GL_DEPTH_BUFFER_BIT)
 167           && ctx->DrawBuffer->Visual.haveDepthBuffer) {
 168          bufferMask |= BUFFER_BIT_DEPTH;
 169       }
 170
 171       if ((mask & GL_STENCIL_BUFFER_BIT)
 172           && ctx->DrawBuffer->Visual.haveStencilBuffer) {
 173          bufferMask |= BUFFER_BIT_STENCIL;
 174       }
 175
 176       if ((mask & GL_ACCUM_BUFFER_BIT)
 177           && ctx->DrawBuffer->Visual.haveAccumBuffer) {
 178          bufferMask |= BUFFER_BIT_ACCUM;
 179       }
 180
 181       ASSERT(ctx->Driver.Clear);
 182       ctx->Driver.Clear(ctx, bufferMask);
 183    }
 184 }