From 26e949b26effe741f9792e3efcba31c7209f3465 Mon Sep 17 00:00:00 2001 From: Kenneth Graunke Date: Thu, 7 Aug 2014 22:42:55 -0700 Subject: [PATCH] mesa: Fix glGetActiveAttribute for gl_VertexID when lowered. The lower_vertex_id pass converts uses of the gl_VertexID system value to the gl_BaseVertex and gl_VertexIDMESA system values. Since gl_VertexID is no longer accessed, it would not be considered active. Of course, it should be, since the shader uses gl_VertexID. v2: Move the var->name dereference past the var != NULL check. Signed-off-by: Kenneth Graunke Reviewed-by: Ian Romanick --- src/mesa/main/shader_query.cpp | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/src/mesa/main/shader_query.cpp b/src/mesa/main/shader_query.cpp index 4871d09657c..766ad296565 100644 --- a/src/mesa/main/shader_query.cpp +++ b/src/mesa/main/shader_query.cpp @@ -93,6 +93,7 @@ is_active_attrib(const ir_variable *var) * and gl_InstanceID." */ return var->data.location == SYSTEM_VALUE_VERTEX_ID || + var->data.location == SYSTEM_VALUE_VERTEX_ID_ZERO_BASE || var->data.location == SYSTEM_VALUE_INSTANCE_ID; default: @@ -133,7 +134,18 @@ _mesa_GetActiveAttrib(GLhandleARB program, GLuint desired_index, continue; if (current_index == desired_index) { - _mesa_copy_string(name, maxLength, length, var->name); + const char *var_name = var->name; + + /* Since gl_VertexID may be lowered to gl_VertexIDMESA, we need to + * consider gl_VertexIDMESA as gl_VertexID for purposes of checking + * active attributes. + */ + if (var->data.mode == ir_var_system_value && + var->data.location == SYSTEM_VALUE_VERTEX_ID_ZERO_BASE) { + var_name = "gl_VertexID"; + } + + _mesa_copy_string(name, maxLength, length, var_name); if (size) *size = (var->type->is_array()) ? var->type->length : 1; -- 2.30.2