| /* |
| * Mesa 3-D graphics library |
| * |
| * 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 |
| * THE AUTHORS OR COPYRIGHT HOLDERS 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 "context.h" |
| #include "enums.h" |
| #include "fbobject.h" |
| #include "mtypes.h" |
| #include "util/bitscan.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 struct gl_context *ctx, |
| const struct gl_framebuffer *fb) |
| { |
| GLbitfield mask = 0x0; |
| |
| if (_mesa_is_user_fbo(fb)) { |
| /* A user-created renderbuffer */ |
| mask = ((1 << ctx->Const.MaxColorAttachments) - 1) << BUFFER_COLOR0; |
| } |
| 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(const struct gl_context *ctx, GLenum buffer) |
| { |
| switch (buffer) { |
| case GL_NONE: |
| return 0; |
| case GL_FRONT: |
| return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_FRONT_RIGHT; |
| case GL_BACK: |
| if (_mesa_is_gles(ctx)) { |
| /* Page 181 (page 192 of the PDF) in section 4.2.1 of the OpenGL |
| * ES 3.0.1 specification says: |
| * |
| * "When draw buffer zero is BACK, color values are written |
| * into the sole buffer for single-buffered contexts, or into |
| * the back buffer for double-buffered contexts." |
| * |
| * Since there is no stereo rendering in ES 3.0, only return the |
| * LEFT bits. This also satisfies the "n must be 1" requirement. |
| * |
| * We also do this for GLES 1 and 2 because those APIs have no |
| * concept of selecting the front and back buffer anyway and it's |
| * convenient to be able to maintain the magic behaviour of |
| * GL_BACK in that case. |
| */ |
| if (ctx->DrawBuffer->Visual.doubleBufferMode) |
| return BUFFER_BIT_BACK_LEFT; |
| return BUFFER_BIT_FRONT_LEFT; |
| } |
| 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: |
| case GL_AUX2: |
| case GL_AUX3: |
| return 1 << BUFFER_COUNT; /* invalid, but not BAD_MASK */ |
| 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: |
| /* not an error, but also not supported */ |
| if (buffer >= GL_COLOR_ATTACHMENT8 && buffer <= GL_COLOR_ATTACHMENT31) |
| return 1 << BUFFER_COUNT; |
| /* 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 gl_buffer_index |
| read_buffer_enum_to_index(const struct gl_context *ctx, GLenum buffer) |
| { |
| switch (buffer) { |
| case GL_FRONT: |
| return BUFFER_FRONT_LEFT; |
| case GL_BACK: |
| if (_mesa_is_gles(ctx)) { |
| /* In draw_buffer_enum_to_bitmask, when GLES contexts draw to |
| * GL_BACK with a single-buffered configuration, we actually end |
| * up drawing to the sole front buffer in our internal |
| * representation. For consistency, we must read from that |
| * front left buffer too. |
| */ |
| if (!ctx->DrawBuffer->Visual.doubleBufferMode) |
| return BUFFER_FRONT_LEFT; |
| } |
| 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: |
| case GL_AUX2: |
| case GL_AUX3: |
| return BUFFER_COUNT; /* invalid, but not -1 */ |
| 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: |
| /* not an error, but also not supported */ |
| if (buffer >= GL_COLOR_ATTACHMENT8 && buffer <= GL_COLOR_ATTACHMENT31) |
| return BUFFER_COUNT; |
| /* error */ |
| return -1; |
| } |
| } |
| |
| static bool |
| is_legal_es3_readbuffer_enum(GLenum buf) |
| { |
| return buf == GL_BACK || buf == GL_NONE || |
| (buf >= GL_COLOR_ATTACHMENT0 && buf <= GL_COLOR_ATTACHMENT31); |
| } |
| |
| /** |
| * Called by glDrawBuffer() and glNamedFramebufferDrawBuffer(). |
| * Specify which renderbuffer(s) to draw into for the first color output. |
| * <buffer> can name zero, one, two or four renderbuffers! |
| * \sa _mesa_DrawBuffers |
| * |
| * \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 or a user-created |
| * framebuffer object. |
| * 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. |
| */ |
| static void |
| draw_buffer(struct gl_context *ctx, struct gl_framebuffer *fb, |
| GLenum buffer, const char *caller) |
| { |
| GLbitfield destMask; |
| |
| FLUSH_VERTICES(ctx, 0); |
| |
| if (MESA_VERBOSE & VERBOSE_API) { |
| _mesa_debug(ctx, "%s %s\n", caller, _mesa_enum_to_string(buffer)); |
| } |
| |
| if (buffer == GL_NONE) { |
| destMask = 0x0; |
| } |
| else { |
| const GLbitfield supportedMask |
| = supported_buffer_bitmask(ctx, fb); |
| destMask = draw_buffer_enum_to_bitmask(ctx, buffer); |
| if (destMask == BAD_MASK) { |
| /* totally bogus buffer */ |
| _mesa_error(ctx, GL_INVALID_ENUM, "%s(invalid buffer %s)", caller, |
| _mesa_enum_to_string(buffer)); |
| return; |
| } |
| destMask &= supportedMask; |
| if (destMask == 0x0) { |
| /* none of the named color buffers exist! */ |
| _mesa_error(ctx, GL_INVALID_OPERATION, "%s(invalid buffer %s)", |
| caller, _mesa_enum_to_string(buffer)); |
| return; |
| } |
| } |
| |
| /* if we get here, there's no error so set new state */ |
| _mesa_drawbuffers(ctx, fb, 1, &buffer, &destMask); |
| |
| /* Call device driver function only if fb is the bound draw buffer */ |
| if (fb == ctx->DrawBuffer) { |
| if (ctx->Driver.DrawBuffers) |
| ctx->Driver.DrawBuffers(ctx, 1, &buffer); |
| else if (ctx->Driver.DrawBuffer) |
| ctx->Driver.DrawBuffer(ctx, buffer); |
| } |
| } |
| |
| |
| void GLAPIENTRY |
| _mesa_DrawBuffer(GLenum buffer) |
| { |
| GET_CURRENT_CONTEXT(ctx); |
| draw_buffer(ctx, ctx->DrawBuffer, buffer, "glDrawBuffer"); |
| } |
| |
| |
| void GLAPIENTRY |
| _mesa_NamedFramebufferDrawBuffer(GLuint framebuffer, GLenum buf) |
| { |
| GET_CURRENT_CONTEXT(ctx); |
| struct gl_framebuffer *fb; |
| |
| if (framebuffer) { |
| fb = _mesa_lookup_framebuffer_err(ctx, framebuffer, |
| "glNamedFramebufferDrawBuffer"); |
| if (!fb) |
| return; |
| } |
| else |
| fb = ctx->WinSysDrawBuffer; |
| |
| draw_buffer(ctx, fb, buf, "glNamedFramebufferDrawBuffer"); |
| } |
| |
| |
| /** |
| * Called by glDrawBuffersARB() and glNamedFramebufferDrawBuffers() to specify |
| * 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. |
| */ |
| static void |
| draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb, |
| GLsizei n, const GLenum *buffers, const char *caller) |
| { |
| GLuint output; |
| GLbitfield usedBufferMask, supportedMask; |
| GLbitfield destMask[MAX_DRAW_BUFFERS]; |
| |
| FLUSH_VERTICES(ctx, 0); |
| |
| /* Turns out n==0 is a valid input that should not produce an error. |
| * The remaining code below correctly handles the n==0 case. |
| * |
| * From the OpenGL 3.0 specification, page 258: |
| * "An INVALID_VALUE error is generated if n is greater than |
| * MAX_DRAW_BUFFERS." |
| */ |
| if (n < 0) { |
| _mesa_error(ctx, GL_INVALID_VALUE, "%s(n < 0)", caller); |
| return; |
| } |
| |
| if (n > (GLsizei) ctx->Const.MaxDrawBuffers) { |
| _mesa_error(ctx, GL_INVALID_VALUE, |
| "%s(n > maximum number of draw buffers)", caller); |
| return; |
| } |
| |
| supportedMask = supported_buffer_bitmask(ctx, fb); |
| usedBufferMask = 0x0; |
| |
| /* From the ES 3.0 specification, page 180: |
| * "If the GL is bound to the default framebuffer, then n must be 1 |
| * and the constant must be BACK or NONE." |
| * (same restriction applies with GL_EXT_draw_buffers specification) |
| */ |
| if (ctx->API == API_OPENGLES2 && _mesa_is_winsys_fbo(fb) && |
| (n != 1 || (buffers[0] != GL_NONE && buffers[0] != GL_BACK))) { |
| _mesa_error(ctx, GL_INVALID_OPERATION, "%s(invalid buffers)", caller); |
| return; |
| } |
| |
| /* complicated error checking... */ |
| for (output = 0; output < n; output++) { |
| destMask[output] = draw_buffer_enum_to_bitmask(ctx, buffers[output]); |
| |
| /* From the OpenGL 3.0 specification, page 258: |
| * "Each buffer listed in bufs must be one of the values from tables |
| * 4.5 or 4.6. Otherwise, an INVALID_ENUM error is generated. |
| */ |
| if (destMask[output] == BAD_MASK) { |
| _mesa_error(ctx, GL_INVALID_ENUM, "%s(invalid buffer %s)", |
| caller, _mesa_enum_to_string(buffers[output])); |
| return; |
| } |
| |
| /* From the OpenGL 4.0 specification, page 256: |
| * "For both the default framebuffer and framebuffer objects, the |
| * constants FRONT, BACK, LEFT, RIGHT, and FRONT_AND_BACK are not |
| * valid in the bufs array passed to DrawBuffers, and will result in |
| * the error INVALID_ENUM. This restriction is because these |
| * constants may themselves refer to multiple buffers, as shown in |
| * table 4.4." |
| * Previous versions of the OpenGL specification say INVALID_OPERATION, |
| * but the Khronos conformance tests expect INVALID_ENUM. |
| */ |
| if (_mesa_bitcount(destMask[output]) > 1) { |
| _mesa_error(ctx, GL_INVALID_ENUM, "%s(invalid buffer %s)", |
| caller, _mesa_enum_to_string(buffers[output])); |
| return; |
| } |
| |
| /* Section 4.2 (Whole Framebuffer Operations) of the OpenGL ES 3.0 |
| * specification says: |
| * |
| * "If the GL is bound to a draw framebuffer object, the ith buffer |
| * listed in bufs must be COLOR_ATTACHMENTi or NONE . Specifying a |
| * buffer out of order, BACK , or COLOR_ATTACHMENTm where m is greater |
| * than or equal to the value of MAX_- COLOR_ATTACHMENTS , will |
| * generate the error INVALID_OPERATION . |
| */ |
| if (_mesa_is_gles3(ctx) && _mesa_is_user_fbo(fb) && |
| buffers[output] != GL_NONE && |
| (buffers[output] < GL_COLOR_ATTACHMENT0 || |
| buffers[output] >= GL_COLOR_ATTACHMENT0 + ctx->Const.MaxColorAttachments)) { |
| _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffers(buffer)"); |
| return; |
| } |
| |
| if (buffers[output] == GL_NONE) { |
| destMask[output] = 0x0; |
| } |
| else { |
| /* Page 259 (page 275 of the PDF) in section 4.2.1 of the OpenGL 3.0 |
| * spec (20080923) says: |
| * |
| * "If the GL is bound to a framebuffer object and DrawBuffers is |
| * supplied with [...] COLOR_ATTACHMENTm where m is greater than |
| * or equal to the value of MAX_COLOR_ATTACHMENTS, then the error |
| * INVALID_OPERATION results." |
| */ |
| if (_mesa_is_user_fbo(fb) && buffers[output] >= |
| GL_COLOR_ATTACHMENT0 + ctx->Const.MaxDrawBuffers) { |
| _mesa_error(ctx, GL_INVALID_OPERATION, |
| "%s(buffers[%d] >= maximum number of draw buffers)", |
| caller, output); |
| return; |
| } |
| |
| /* From the OpenGL 3.0 specification, page 259: |
| * "If the GL is bound to the default framebuffer and DrawBuffers is |
| * supplied with a constant (other than NONE) that does not indicate |
| * any of the color buffers allocated to the GL context by the window |
| * system, the error INVALID_OPERATION will be generated. |
| * |
| * If the GL is bound to a framebuffer object and DrawBuffers is |
| * supplied with a constant from table 4.6 [...] then the error |
| * INVALID_OPERATION results." |
| */ |
| destMask[output] &= supportedMask; |
| if (destMask[output] == 0) { |
| _mesa_error(ctx, GL_INVALID_OPERATION, |
| "%s(unsupported buffer %s)", |
| caller, _mesa_enum_to_string(buffers[output])); |
| return; |
| } |
| |
| /* ES 3.0 is even more restrictive. From the ES 3.0 spec, page 180: |
| * "If the GL is bound to a framebuffer object, the ith buffer listed |
| * in bufs must be COLOR_ATTACHMENTi or NONE. [...] INVALID_OPERATION." |
| * (same restriction applies with GL_EXT_draw_buffers specification) |
| */ |
| if (ctx->API == API_OPENGLES2 && _mesa_is_user_fbo(fb) && |
| buffers[output] != GL_NONE && |
| buffers[output] != GL_COLOR_ATTACHMENT0 + output) { |
| _mesa_error(ctx, GL_INVALID_OPERATION, |
| "%s(unsupported buffer %s)", |
| caller, _mesa_enum_to_string(buffers[output])); |
| return; |
| } |
| |
| /* From the OpenGL 3.0 specification, page 258: |
| * "Except for NONE, a buffer may not appear more than once in the |
| * array pointed to by bufs. Specifying a buffer more then once will |
| * result in the error INVALID_OPERATION." |
| */ |
| if (destMask[output] & usedBufferMask) { |
| _mesa_error(ctx, GL_INVALID_OPERATION, |
| "%s(duplicated buffer %s)", |
| caller, _mesa_enum_to_string(buffers[output])); |
| return; |
| } |
| |
| /* update bitmask */ |
| usedBufferMask |= destMask[output]; |
| } |
| } |
| |
| /* OK, if we get here, there were no errors so set the new state */ |
| _mesa_drawbuffers(ctx, fb, n, buffers, destMask); |
| |
| /* |
| * Call device driver function if fb is the bound draw buffer. |
| * Note that n can be equal to 0, |
| * in which case we don't want to reference buffers[0], which |
| * may not be valid. |
| */ |
| if (fb == ctx->DrawBuffer) { |
| if (ctx->Driver.DrawBuffers) |
| ctx->Driver.DrawBuffers(ctx, n, buffers); |
| else if (ctx->Driver.DrawBuffer) |
| ctx->Driver.DrawBuffer(ctx, n > 0 ? buffers[0] : GL_NONE); |
| } |
| } |
| |
| |
| void GLAPIENTRY |
| _mesa_DrawBuffers(GLsizei n, const GLenum *buffers) |
| { |
| GET_CURRENT_CONTEXT(ctx); |
| draw_buffers(ctx, ctx->DrawBuffer, n, buffers, "glDrawBuffers"); |
| } |
| |
| |
| void GLAPIENTRY |
| _mesa_NamedFramebufferDrawBuffers(GLuint framebuffer, GLsizei n, |
| const GLenum *bufs) |
| { |
| GET_CURRENT_CONTEXT(ctx); |
| struct gl_framebuffer *fb; |
| |
| if (framebuffer) { |
| fb = _mesa_lookup_framebuffer_err(ctx, framebuffer, |
| "glNamedFramebufferDrawBuffers"); |
| if (!fb) |
| return; |
| } |
| else |
| fb = ctx->WinSysDrawBuffer; |
| |
| draw_buffers(ctx, fb, n, bufs, "glNamedFramebufferDrawBuffers"); |
| } |
| |
| |
| /** |
| * Performs necessary state updates when _mesa_drawbuffers makes an |
| * actual change. |
| */ |
| static void |
| updated_drawbuffers(struct gl_context *ctx, struct gl_framebuffer *fb) |
| { |
| FLUSH_VERTICES(ctx, _NEW_BUFFERS); |
| |
| if (ctx->API == API_OPENGL_COMPAT && !ctx->Extensions.ARB_ES2_compatibility) { |
| /* Flag the FBO as requiring validation. */ |
| if (_mesa_is_user_fbo(fb)) { |
| fb->_Status = 0; |
| } |
| } |
| } |
| |
| |
| /** |
| * Helper function to set the GL_DRAW_BUFFER state for the given context and |
| * FBO. Called via glDrawBuffer(), glDrawBuffersARB() |
| * |
| * 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 fb the desired draw buffer |
| * \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(struct gl_context *ctx, struct gl_framebuffer *fb, |
| GLuint n, const GLenum *buffers, const GLbitfield *destMask) |
| { |
| GLbitfield mask[MAX_DRAW_BUFFERS]; |
| GLuint buf; |
| |
| 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(ctx, buffers[output]); |
| assert(mask[output] != BAD_MASK); |
| mask[output] &= supportedMask; |
| } |
| destMask = mask; |
| } |
| |
| /* |
| * destMask[0] may have up to four bits set |
| * (ex: glDrawBuffer(GL_FRONT_AND_BACK)). |
| * Otherwise, destMask[x] can only have one bit set. |
| */ |
| if (n > 0 && _mesa_bitcount(destMask[0]) > 1) { |
| GLuint count = 0, destMask0 = destMask[0]; |
| while (destMask0) { |
| const int bufIndex = u_bit_scan(&destMask0); |
| if (fb->_ColorDrawBufferIndexes[count] != bufIndex) { |
| updated_drawbuffers(ctx, fb); |
| fb->_ColorDrawBufferIndexes[count] = bufIndex; |
| } |
| count++; |
| } |
| fb->ColorDrawBuffer[0] = buffers[0]; |
| fb->_NumColorDrawBuffers = count; |
| } |
| else { |
| GLuint count = 0; |
| for (buf = 0; buf < n; buf++ ) { |
| if (destMask[buf]) { |
| GLint bufIndex = ffs(destMask[buf]) - 1; |
| /* only one bit should be set in the destMask[buf] field */ |
| assert(_mesa_bitcount(destMask[buf]) == 1); |
| if (fb->_ColorDrawBufferIndexes[buf] != bufIndex) { |
| updated_drawbuffers(ctx, fb); |
| fb->_ColorDrawBufferIndexes[buf] = bufIndex; |
| } |
| count = buf + 1; |
| } |
| else { |
| if (fb->_ColorDrawBufferIndexes[buf] != -1) { |
| updated_drawbuffers(ctx, fb); |
| fb->_ColorDrawBufferIndexes[buf] = -1; |
| } |
| } |
| fb->ColorDrawBuffer[buf] = buffers[buf]; |
| } |
| fb->_NumColorDrawBuffers = count; |
| } |
| |
| /* set remaining outputs to -1 (GL_NONE) */ |
| for (buf = fb->_NumColorDrawBuffers; buf < ctx->Const.MaxDrawBuffers; buf++) { |
| if (fb->_ColorDrawBufferIndexes[buf] != -1) { |
| updated_drawbuffers(ctx, fb); |
| fb->_ColorDrawBufferIndexes[buf] = -1; |
| } |
| } |
| for (buf = n; buf < ctx->Const.MaxDrawBuffers; buf++) { |
| fb->ColorDrawBuffer[buf] = GL_NONE; |
| } |
| |
| if (_mesa_is_winsys_fbo(fb)) { |
| /* also set context drawbuffer state */ |
| for (buf = 0; buf < ctx->Const.MaxDrawBuffers; buf++) { |
| if (ctx->Color.DrawBuffer[buf] != fb->ColorDrawBuffer[buf]) { |
| updated_drawbuffers(ctx, fb); |
| ctx->Color.DrawBuffer[buf] = fb->ColorDrawBuffer[buf]; |
| } |
| } |
| } |
| } |
| |
| |
| /** |
| * Update the current drawbuffer's _ColorDrawBufferIndex[] list, etc. |
| * from the context's Color.DrawBuffer[] state. |
| * Use when changing contexts. |
| */ |
| void |
| _mesa_update_draw_buffers(struct gl_context *ctx) |
| { |
| /* should be a window system FBO */ |
| assert(_mesa_is_winsys_fbo(ctx->DrawBuffer)); |
| |
| _mesa_drawbuffers(ctx, ctx->DrawBuffer, ctx->Const.MaxDrawBuffers, |
| ctx->Color.DrawBuffer, NULL); |
| } |
| |
| |
| /** |
| * Like \sa _mesa_drawbuffers(), this is a helper function for setting |
| * GL_READ_BUFFER state for the given context and FBO. |
| * Note that all error checking should have been done before calling |
| * this function. |
| * \param ctx the rendering context |
| * \param fb the framebuffer object to update |
| * \param buffer GL_FRONT, GL_BACK, GL_COLOR_ATTACHMENT0, etc. |
| * \param bufferIndex the numerical index corresponding to 'buffer' |
| */ |
| void |
| _mesa_readbuffer(struct gl_context *ctx, struct gl_framebuffer *fb, |
| GLenum buffer, gl_buffer_index bufferIndex) |
| { |
| if ((fb == ctx->ReadBuffer) && _mesa_is_winsys_fbo(fb)) { |
| /* 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_BUFFERS; |
| } |
| |
| |
| |
| /** |
| * Called by glReadBuffer and glNamedFramebufferReadBuffer to set the source |
| * renderbuffer for reading pixels. |
| * \param mode color buffer such as GL_FRONT, GL_BACK, etc. |
| */ |
| static void |
| read_buffer(struct gl_context *ctx, struct gl_framebuffer *fb, |
| GLenum buffer, const char *caller) |
| { |
| GLbitfield supportedMask; |
| gl_buffer_index srcBuffer; |
| |
| FLUSH_VERTICES(ctx, 0); |
| |
| if (MESA_VERBOSE & VERBOSE_API) |
| _mesa_debug(ctx, "%s %s\n", caller, _mesa_enum_to_string(buffer)); |
| |
| if (buffer == GL_NONE) { |
| /* This is legal--it means that no buffer should be bound for reading. */ |
| srcBuffer = -1; |
| } |
| else { |
| /* general case / window-system framebuffer */ |
| if (_mesa_is_gles3(ctx) && !is_legal_es3_readbuffer_enum(buffer)) |
| srcBuffer = -1; |
| else |
| srcBuffer = read_buffer_enum_to_index(ctx, buffer); |
| |
| if (srcBuffer == -1) { |
| _mesa_error(ctx, GL_INVALID_ENUM, |
| "%s(invalid buffer %s)", caller, |
| _mesa_enum_to_string(buffer)); |
| return; |
| } |
| supportedMask = supported_buffer_bitmask(ctx, fb); |
| if (((1 << srcBuffer) & supportedMask) == 0) { |
| _mesa_error(ctx, GL_INVALID_OPERATION, |
| "%s(invalid buffer %s)", caller, |
| _mesa_enum_to_string(buffer)); |
| return; |
| } |
| } |
| |
| /* OK, all error checking has been completed now */ |
| |
| _mesa_readbuffer(ctx, fb, buffer, srcBuffer); |
| |
| /* Call the device driver function only if fb is the bound read buffer */ |
| if (fb == ctx->ReadBuffer) { |
| if (ctx->Driver.ReadBuffer) |
| ctx->Driver.ReadBuffer(ctx, buffer); |
| } |
| } |
| |
| |
| void GLAPIENTRY |
| _mesa_ReadBuffer(GLenum buffer) |
| { |
| GET_CURRENT_CONTEXT(ctx); |
| read_buffer(ctx, ctx->ReadBuffer, buffer, "glReadBuffer"); |
| } |
| |
| |
| void GLAPIENTRY |
| _mesa_NamedFramebufferReadBuffer(GLuint framebuffer, GLenum src) |
| { |
| GET_CURRENT_CONTEXT(ctx); |
| struct gl_framebuffer *fb; |
| |
| if (framebuffer) { |
| fb = _mesa_lookup_framebuffer_err(ctx, framebuffer, |
| "glNamedFramebufferReadBuffer"); |
| if (!fb) |
| return; |
| } |
| else |
| fb = ctx->WinSysReadBuffer; |
| |
| read_buffer(ctx, fb, src, "glNamedFramebufferReadBuffer"); |
| } |
