From dea0d4d56326f148a42c766bdbaf1b5bb247cc59 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Mon, 2 Feb 2009 16:33:08 -0700 Subject: mesa: fix GLSL issue preventing use of all 16 generic vertex attributes Only 15 actually worked before since we always reserved generic[0] as an alias for vertex position. The case of vertex attribute 0 is tricky. The spec says that there is no aliasing between generic vertex attributes 0..MAX_VERTEX_ATTRIBS-1 and the conventional attributes. But it also says that calls to glVertexAttrib(0, v) are equivalent to glVertex(v). The distinction seems to be in glVertex-mode versus vertex array mode. So update the VBO code so that if the shader uses generic[0] but not gl_Vertex, route the attribute data set with glVertex() to go to shader input generic[0]. No change needed for the glDrawArrays/Elements() path. This is a potentially risky change so regressions are possible. All the usual tests seem OK though. --- src/mesa/shader/slang/slang_link.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'src/mesa/shader/slang/slang_link.c') diff --git a/src/mesa/shader/slang/slang_link.c b/src/mesa/shader/slang/slang_link.c index c6d5cc05668..77bcda08716 100644 --- a/src/mesa/shader/slang/slang_link.c +++ b/src/mesa/shader/slang/slang_link.c @@ -318,7 +318,7 @@ _slang_resolve_attributes(struct gl_shader_program *shProg, { GLint attribMap[MAX_VERTEX_ATTRIBS]; GLuint i, j; - GLbitfield usedAttributes; + GLbitfield usedAttributes; /* generics only, not legacy attributes */ assert(origProg != linkedProg); assert(origProg->Target == GL_VERTEX_PROGRAM_ARB); @@ -342,6 +342,15 @@ _slang_resolve_attributes(struct gl_shader_program *shProg, usedAttributes |= (1 << attr); } + /* If gl_Vertex is used, that actually counts against the limit + * on generic vertex attributes. This avoids the ambiguity of + * whether glVertexAttrib4fv(0, v) sets legacy attribute 0 (vert pos) + * or generic attribute[0]. If gl_Vertex is used, we want the former. + */ + if (origProg->InputsRead & VERT_BIT_POS) { + usedAttributes |= 0x1; + } + /* initialize the generic attribute map entries to -1 */ for (i = 0; i < MAX_VERTEX_ATTRIBS; i++) { attribMap[i] = -1; @@ -384,7 +393,7 @@ _slang_resolve_attributes(struct gl_shader_program *shProg, * Start at 1 since generic attribute 0 always aliases * glVertex/position. */ - for (attr = 1; attr < MAX_VERTEX_ATTRIBS; attr++) { + for (attr = 0; attr < MAX_VERTEX_ATTRIBS; attr++) { if (((1 << attr) & usedAttributes) == 0) break; } -- cgit v1.2.3