/* * Mesa 3-D graphics library * Version: 7.1 * * Copyright (C) 1999-2007 Brian Paul All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ /** * \file buffers.c * glReadBuffer, DrawBuffer functions. */ #include "glheader.h" #include "buffers.h" #include "colormac.h" #include "context.h" #include "enums.h" #include "fbobject.h" #include "state.h" #define BAD_MASK ~0u /** * Return bitmask of BUFFER_BIT_* flags indicating which color buffers are * available to the rendering context (for drawing or reading). * This depends on the type of framebuffer. For window system framebuffers * we look at the framebuffer's visual. But for user-create framebuffers we * look at the number of supported color attachments. * \param fb the framebuffer to draw to, or read from * \return bitmask of BUFFER_BIT_* flags */ static GLbitfield supported_buffer_bitmask(const GLcontext *ctx, const struct gl_framebuffer *fb) { GLbitfield mask = 0x0; if (fb->Name > 0) { /* A user-created renderbuffer */ GLuint i; ASSERT(ctx->Extensions.EXT_framebuffer_object); for (i = 0; i < ctx->Const.MaxColorAttachments; i++) { mask |= (BUFFER_BIT_COLOR0 << i); } } else { /* A window system framebuffer */ GLint i; mask = BUFFER_BIT_FRONT_LEFT; /* always have this */ if (fb->Visual.stereoMode) { mask |= BUFFER_BIT_FRONT_RIGHT; if (fb->Visual.doubleBufferMode) { mask |= BUFFER_BIT_BACK_LEFT | BUFFER_BIT_BACK_RIGHT; } } else if (fb->Visual.doubleBufferMode) { mask |= BUFFER_BIT_BACK_LEFT; } for (i = 0; i < fb->Visual.numAuxBuffers; i++) { mask |= (BUFFER_BIT_AUX0 << i); } } return mask; } /** * Helper routine used by glDrawBuffer and glDrawBuffersARB. * Given a GLenum naming one or more color buffers (such as * GL_FRONT_AND_BACK), return the corresponding bitmask of BUFFER_BIT_* flags. */ static GLbitfield draw_buffer_enum_to_bitmask(GLenum buffer) { switch (buffer) { case GL_NONE: return 0; case GL_FRONT: return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_FRONT_RIGHT; case GL_BACK: return BUFFER_BIT_BACK_LEFT | BUFFER_BIT_BACK_RIGHT; case GL_RIGHT: return BUFFER_BIT_FRONT_RIGHT | BUFFER_BIT_BACK_RIGHT; case GL_FRONT_RIGHT: return BUFFER_BIT_FRONT_RIGHT; case GL_BACK_RIGHT: return BUFFER_BIT_BACK_RIGHT; case GL_BACK_LEFT: return BUFFER_BIT_BACK_LEFT; case GL_FRONT_AND_BACK: return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT | BUFFER_BIT_FRONT_RIGHT | BUFFER_BIT_BACK_RIGHT; case GL_LEFT: return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT; case GL_FRONT_LEFT: return BUFFER_BIT_FRONT_LEFT; case GL_AUX0: return BUFFER_BIT_AUX0; case GL_AUX1: return BUFFER_BIT_AUX1; case GL_AUX2: return BUFFER_BIT_AUX2; case GL_AUX3: return BUFFER_BIT_AUX3; case GL_COLOR_ATTACHMENT0_EXT: return BUFFER_BIT_COLOR0; case GL_COLOR_ATTACHMENT1_EXT: return BUFFER_BIT_COLOR1; case GL_COLOR_ATTACHMENT2_EXT: return BUFFER_BIT_COLOR2; case GL_COLOR_ATTACHMENT3_EXT: return BUFFER_BIT_COLOR3; case GL_COLOR_ATTACHMENT4_EXT: return BUFFER_BIT_COLOR4; case GL_COLOR_ATTACHMENT5_EXT: return BUFFER_BIT_COLOR5; case GL_COLOR_ATTACHMENT6_EXT: return BUFFER_BIT_COLOR6; case GL_COLOR_ATTACHMENT7_EXT: return BUFFER_BIT_COLOR7; default: /* error */ return BAD_MASK; } } /** * Helper routine used by glReadBuffer. * Given a GLenum naming a color buffer, return the index of the corresponding * renderbuffer (a BUFFER_* value). * return -1 for an invalid buffer. */ static GLint read_buffer_enum_to_index(GLenum buffer) { switch (buffer) { case GL_FRONT: return BUFFER_FRONT_LEFT; case GL_BACK: return BUFFER_BACK_LEFT; case GL_RIGHT: return BUFFER_FRONT_RIGHT; case GL_FRONT_RIGHT: return BUFFER_FRONT_RIGHT; case GL_BACK_RIGHT: return BUFFER_BACK_RIGHT; case GL_BACK_LEFT: return BUFFER_BACK_LEFT; case GL_LEFT: return BUFFER_FRONT_LEFT; case GL_FRONT_LEFT: return BUFFER_FRONT_LEFT; case GL_AUX0: return BUFFER_AUX0; case GL_AUX1: return BUFFER_AUX1; case GL_AUX2: return BUFFER_AUX2; case GL_AUX3: return BUFFER_AUX3; case GL_COLOR_ATTACHMENT0_EXT: return BUFFER_COLOR0; case GL_COLOR_ATTACHMENT1_EXT: return BUFFER_COLOR1; case GL_COLOR_ATTACHMENT2_EXT: return BUFFER_COLOR2; case GL_COLOR_ATTACHMENT3_EXT: return BUFFER_COLOR3; case GL_COLOR_ATTACHMENT4_EXT: return BUFFER_COLOR4; case GL_COLOR_ATTACHMENT5_EXT: return BUFFER_COLOR5; case GL_COLOR_ATTACHMENT6_EXT: return BUFFER_COLOR6; case GL_COLOR_ATTACHMENT7_EXT: return BUFFER_COLOR7; default: /* error */ return -1; } } /** * Called by glDrawBuffer(). * Specify which renderbuffer(s) to draw into for the first color output. * can name zero, one, two or four renderbuffers! * \sa _mesa_DrawBuffersARB * * \param buffer buffer token such as GL_LEFT or GL_FRONT_AND_BACK, etc. * * Note that the behaviour of this function depends on whether the * current ctx->DrawBuffer is a window-system framebuffer (Name=0) or * a user-created framebuffer object (Name!=0). * In the former case, we update the per-context ctx->Color.DrawBuffer * state var _and_ the FB's ColorDrawBuffer state. * In the later case, we update the FB's ColorDrawBuffer state only. * * Furthermore, upon a MakeCurrent() or BindFramebuffer() call, if the * new FB is a window system FB, we need to re-update the FB's * ColorDrawBuffer state to match the context. This is handled in * _mesa_update_framebuffer(). * * See the GL_EXT_framebuffer_object spec for more info. */ void GLAPIENTRY _mesa_DrawBuffer(GLenum buffer) { GLbitfield destMask; GET_CURRENT_CONTEXT(ctx); ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); /* too complex... */ if (MESA_VERBOSE & VERBOSE_API) { _mesa_debug(ctx, "glDrawBuffer %s\n", _mesa_lookup_enum_by_nr(buffer)); } if (buffer == GL_NONE) { destMask = 0x0; } else { const GLbitfield supportedMask = supported_buffer_bitmask(ctx, ctx->DrawBuffer); destMask = draw_buffer_enum_to_bitmask(buffer); if (destMask == BAD_MASK) { /* totally bogus buffer */ _mesa_error(ctx, GL_INVALID_ENUM, "glDrawBuffer(buffer)"); return; } destMask &= supportedMask; if (destMask == 0x0) { /* none of the named color buffers exist! */ _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffer(buffer)"); return; } } /* if we get here, there's no error so set new state */ _mesa_drawbuffers(ctx, 1, &buffer, &destMask); /* * Call device driver function. */ if (ctx->Driver.DrawBuffers) ctx->Driver.DrawBuffers(ctx, 1, &buffer); else if (ctx->Driver.DrawBuffer) ctx->Driver.DrawBuffer(ctx, buffer); } /** * Called by glDrawBuffersARB; specifies the destination color renderbuffers * for N fragment program color outputs. * \sa _mesa_DrawBuffer * \param n number of outputs * \param buffers array [n] of renderbuffer names. Unlike glDrawBuffer, the * names cannot specify more than one buffer. For example, * GL_FRONT_AND_BACK is illegal. */ void GLAPIENTRY _mesa_DrawBuffersARB(GLsizei n, const GLenum *buffers) { GLint output; GLbitfield usedBufferMask, supportedMask; GLbitfield destMask[MAX_DRAW_BUFFERS]; GET_CURRENT_CONTEXT(ctx); ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); if (!ctx->Extensions.ARB_draw_buffers) { _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffersARB"); return; } if (n < 1 || n > (GLsizei) ctx->Const.MaxDrawBuffers) { _mesa_error(ctx, GL_INVALID_VALUE, "glDrawBuffersARB(n)"); return; } supportedMask = supported_buffer_bitmask(ctx, ctx->DrawBuffer); usedBufferMask = 0x0; /* complicated error checking... */ for (output = 0; output < n; output++) { if (buffers[output] == GL_NONE) { destMask[output] = 0x0; } else { destMask[output] = draw_buffer_enum_to_bitmask(buffers[output]); if (destMask[output] == BAD_MASK || _mesa_bitcount(destMask[output]) > 1) { _mesa_error(ctx, GL_INVALID_ENUM, "glDrawBuffersARB(buffer)"); return; } destMask[output] &= supportedMask; if (destMask[output] == 0) { _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffersARB(unsupported buffer)"); return; } if (destMask[output] & usedBufferMask) { /* can't specify a dest buffer more than once! */ _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffersARB(duplicated buffer)"); return; } /* update bitmask */ usedBufferMask |= destMask[output]; } } /* OK, if we get here, there were no errors so set the new state */ _mesa_drawbuffers(ctx, n, buffers, destMask); /* * Call device driver function. */ if (ctx->Driver.DrawBuffers) ctx->Driver.DrawBuffers(ctx, n, buffers); else if (ctx->Driver.DrawBuffer) ctx->Driver.DrawBuffer(ctx, buffers[0]); } /** * Helper function to set the GL_DRAW_BUFFER state in the context and * current FBO. * * All error checking will have been done prior to calling this function * so nothing should go wrong at this point. * * \param ctx current context * \param n number of color outputs to set * \param buffers array[n] of colorbuffer names, like GL_LEFT. * \param destMask array[n] of BUFFER_BIT_* bitmasks which correspond to the * colorbuffer names. (i.e. GL_FRONT_AND_BACK => * BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT). */ void _mesa_drawbuffers(GLcontext *ctx, GLuint n, const GLenum *buffers, const GLbitfield *destMask) { struct gl_framebuffer *fb = ctx->DrawBuffer; GLbitfield mask[MAX_DRAW_BUFFERS]; if (!destMask) { /* compute destMask values now */ const GLbitfield supportedMask = supported_buffer_bitmask(ctx, fb); GLuint output; for (output = 0; output < n; output++) { mask[output] = draw_buffer_enum_to_bitmask(buffers[output]); ASSERT(mask[output] != BAD_MASK); mask[output] &= supportedMask; } destMask = mask; } if (n == 1) { GLuint buf, count = 0; /* init to -1 to help catch errors */ fb->_ColorDrawBufferIndexes[0] = -1; for (buf = 0; buf < BUFFER_COUNT; buf++) { if (destMask[0] & (1 << buf)) { fb->_ColorDrawBufferIndexes[count] = buf; count++; } } fb->ColorDrawBuffer[0] = buffers[0]; fb->_NumColorDrawBuffers = count; } else { GLuint buf, count = 0; for (buf = 0; buf < n; buf++ ) { if (destMask[buf]) { fb->_ColorDrawBufferIndexes[buf] = _mesa_ffs(destMask[buf]) - 1; fb->ColorDrawBuffer[buf] = buffers[buf]; count = buf + 1; } else { fb->_ColorDrawBufferIndexes[buf] = -1; } } /* set remaining outputs to -1 (GL_NONE) */ while (buf < ctx->Const.MaxDrawBuffers) { fb->_ColorDrawBufferIndexes[buf] = -1; fb->ColorDrawBuffer[buf] = GL_NONE; buf++; } fb->_NumColorDrawBuffers = count; } if (fb->Name == 0) { /* also set context drawbuffer state */ GLuint buf; for (buf = 0; buf < ctx->Const.MaxDrawBuffers; buf++) { ctx->Color.DrawBuffer[buf] = fb->ColorDrawBuffer[buf]; } } ctx->NewState |= _NEW_COLOR; } /** * Like \sa _mesa_drawbuffers(), this is a helper function for setting * GL_READ_BUFFER state in the context and current FBO. * \param ctx the rendering context * \param buffer GL_FRONT, GL_BACK, GL_COLOR_ATTACHMENT0, etc. * \param bufferIndex the numerical index corresponding to 'buffer' */ void _mesa_readbuffer(GLcontext *ctx, GLenum buffer, GLint bufferIndex) { struct gl_framebuffer *fb = ctx->ReadBuffer; if (fb->Name == 0) { /* Only update the per-context READ_BUFFER state if we're bound to * a window-system framebuffer. */ ctx->Pixel.ReadBuffer = buffer; } fb->ColorReadBuffer = buffer; fb->_ColorReadBufferIndex = bufferIndex; ctx->NewState |= _NEW_PIXEL; } /** * Called by glReadBuffer to set the source renderbuffer for reading pixels. * \param mode color buffer such as GL_FRONT, GL_BACK, etc. */ void GLAPIENTRY _mesa_ReadBuffer(GLenum buffer) { struct gl_framebuffer *fb; GLbitfield supportedMask; GLint srcBuffer; GET_CURRENT_CONTEXT(ctx); ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); if (MESA_VERBOSE & VERBOSE_API) _mesa_debug(ctx, "glReadBuffer %s\n", _mesa_lookup_enum_by_nr(buffer)); fb = ctx->ReadBuffer; if (MESA_VERBOSE & VERBOSE_API) _mesa_debug(ctx, "glReadBuffer %s\n", _mesa_lookup_enum_by_nr(buffer)); if (fb->Name > 0 && buffer == GL_NONE) { /* This is legal for user-created framebuffer objects */ srcBuffer = -1; } else { /* general case / window-system framebuffer */ srcBuffer = read_buffer_enum_to_index(buffer); if (srcBuffer == -1) { _mesa_error(ctx, GL_INVALID_ENUM, "glReadBuffer(buffer=0x%x)", buffer); return; } supportedMask = supported_buffer_bitmask(ctx, fb); if (((1 << srcBuffer) & supportedMask) == 0) { _mesa_error(ctx, GL_INVALID_OPERATION, "glReadBuffer(buffer=0x%x)", buffer); return; } } /* OK, all error checking has been completed now */ _mesa_readbuffer(ctx, buffer, srcBuffer); /* * Call device driver function. */ if (ctx->Driver.ReadBuffer) (*ctx->Driver.ReadBuffer)(ctx, buffer); } #if _HAVE_FULL_GL /** * XXX THIS IS OBSOLETE - drivers should take care of detecting window * size changes and act accordingly, likely calling _mesa_resize_framebuffer(). * * GL_MESA_resize_buffers extension. * * When this function is called, we'll ask the window system how large * the current window is. If it's a new size, we'll call the driver's * ResizeBuffers function. The driver will then resize its color buffers * as needed, and maybe call the swrast's routine for reallocating * swrast-managed depth/stencil/accum/etc buffers. * \note This function should only be called through the GL API, not * from device drivers (as was done in the past). */ void _mesa_resizebuffers( GLcontext *ctx ) { ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx ); if (MESA_VERBOSE & VERBOSE_API) _mesa_debug(ctx, "glResizeBuffersMESA\n"); if (!ctx->Driver.GetBufferSize) { return; } if (ctx->WinSysDrawBuffer) { GLuint newWidth, newHeight; GLframebuffer *buffer = ctx->WinSysDrawBuffer; assert(buffer->Name == 0); /* ask device driver for size of output buffer */ ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight ); /* see if size of device driver's color buffer (window) has changed */ if (buffer->Width != newWidth || buffer->Height != newHeight) { if (ctx->Driver.ResizeBuffers) ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight ); } } if (ctx->WinSysReadBuffer && ctx->WinSysReadBuffer != ctx->WinSysDrawBuffer) { GLuint newWidth, newHeight; GLframebuffer *buffer = ctx->WinSysReadBuffer; assert(buffer->Name == 0); /* ask device driver for size of read buffer */ ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight ); /* see if size of device driver's color buffer (window) has changed */ if (buffer->Width != newWidth || buffer->Height != newHeight) { if (ctx->Driver.ResizeBuffers) ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight ); } } ctx->NewState |= _NEW_BUFFERS; /* to update scissor / window bounds */ } /* * XXX THIS IS OBSOLETE */ void GLAPIENTRY _mesa_ResizeBuffersMESA( void ) { GET_CURRENT_CONTEXT(ctx); if (ctx->Extensions.MESA_resize_buffers) _mesa_resizebuffers( ctx ); } /* * XXX move somewhere else someday? */ void GLAPIENTRY _mesa_SampleCoverageARB(GLclampf value, GLboolean invert) { GET_CURRENT_CONTEXT(ctx); if (!ctx->Extensions.ARB_multisample) { _mesa_error(ctx, GL_INVALID_OPERATION, "glSampleCoverageARB"); return; } ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx ); ctx->Multisample.SampleCoverageValue = (GLfloat) CLAMP(value, 0.0, 1.0); ctx->Multisample.SampleCoverageInvert = invert; ctx->NewState |= _NEW_MULTISAMPLE; } #endif /* _HAVE_FULL_GL */ /** * Initialize the context's multisample state. * \param ctx the GL context. */ void _mesa_init_multisample(GLcontext *ctx) { ctx->Multisample.Enabled = GL_TRUE; ctx->Multisample.SampleAlphaToCoverage = GL_FALSE; ctx->Multisample.SampleAlphaToOne = GL_FALSE; ctx->Multisample.SampleCoverage = GL_FALSE; ctx->Multisample.SampleCoverageValue = 1.0; ctx->Multisample.SampleCoverageInvert = GL_FALSE; }