From f3db20da1a04fd64732c62631d59aac801a1a59d Mon Sep 17 00:00:00 2001 From: Kenneth Graunke Date: Fri, 16 Nov 2012 14:52:01 -0800 Subject: [PATCH] mesa: Rework crazy error code rules in glDrawBuffers(). Perhaps most importantly, this patch adds comments quoting the relevant spec paragraphs above each error condition. It also makes three changes: - For FBOs, GL_COLOR_ATTACHMENTm where m >= MaxDrawBuffers is supposed to generate INVALID_OPERATION (not INVALID_ENUM). - Constants that refer to multiple buffers (such as FRONT, BACK, LEFT, RIGHT, and FRONT_AND_BACK) are supposed to generate INVALID_OPERATION, not INVALID_ENUM. - In ES 3.0, for FBOs, buffers[i] must be NONE or GL_COLOR_ATTACHMENTi or else INVALID_OPERATION occurs. (This is a new restriction.) Fixes es3conform's draw-buffers-api test. v2: The error path was missing a "return" like all the other error paths. Also, we may as well call it glDrawBuffers in the error message since the ARB suffix doesn't exist in ES 3. Reviewed-by: Jordan Justen Reviewed-by: Ian Romanick --- src/mesa/main/buffers.c | 66 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 63 insertions(+), 3 deletions(-) diff --git a/src/mesa/main/buffers.c b/src/mesa/main/buffers.c index d10a5739479..3dcd46f0180 100644 --- a/src/mesa/main/buffers.c +++ b/src/mesa/main/buffers.c @@ -290,6 +290,10 @@ _mesa_DrawBuffers(GLsizei n, const GLenum *buffers) /* 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 || n > (GLsizei) ctx->Const.MaxDrawBuffers) { _mesa_error(ctx, GL_INVALID_VALUE, "glDrawBuffersARB(n)"); @@ -305,20 +309,76 @@ _mesa_DrawBuffers(GLsizei n, const GLenum *buffers) destMask[output] = 0x0; } else { + /* From the OpenGL 3.0 specification, page 258: + * "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(ctx->DrawBuffer) && buffers[output] >= + GL_COLOR_ATTACHMENT0 + ctx->Const.MaxDrawBuffers) { + _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffersARB(buffer)"); + return; + } + destMask[output] = draw_buffer_enum_to_bitmask(buffers[output]); - if (destMask[output] == BAD_MASK - || _mesa_bitcount(destMask[output]) > 1) { + + /* 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, "glDrawBuffersARB(buffer)"); return; } + + /* From the OpenGL 3.0 specification, page 259: + * "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_OPERATION. This restriction is because these + * constants may themselves refer to multiple buffers, as shown in + * table 4.4." + */ + if (_mesa_bitcount(destMask[output]) > 1) { + _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffersARB(buffer)"); + 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, "glDrawBuffersARB(unsupported buffer)"); 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." + */ + if (_mesa_is_gles3(ctx) && _mesa_is_user_fbo(ctx->DrawBuffer) && + buffers[output] != GL_NONE && + buffers[output] != GL_COLOR_ATTACHMENT0 + output) { + _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffers(buffer)"); + 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) { - /* can't specify a dest buffer more than once! */ _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffersARB(duplicated buffer)"); return; -- 2.30.2