linker: Initial implementation of attribute slot allocation
diff --git a/linker.cpp b/linker.cpp
index 2285f01..314db0b 100644
--- a/linker.cpp
+++ b/linker.cpp
@@ -66,6 +66,7 @@
#include <cstdlib>
#include <cstdio>
+#include "main/mtypes.h"
#include "glsl_symbol_table.h"
#include "glsl_parser_extras.h"
#include "ir.h"
@@ -107,6 +108,24 @@
};
+void
+invalidate_variable_locations(glsl_shader *sh, enum ir_variable_mode mode,
+ int generic_base)
+{
+ foreach_list(node, &sh->ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ if ((var == NULL) || (var->mode != (unsigned) mode))
+ continue;
+
+ /* Only assign locations for generic attributes / varyings / etc.
+ */
+ if (var->location >= generic_base)
+ var->location = -1;
+ }
+}
+
+
/**
* Verify that a vertex shader executable meets all semantic requirements
*
@@ -416,6 +435,66 @@
void
+assign_attribute_locations(glsl_shader *sh,
+ struct gl_program_parameter_list *attrib)
+{
+ unsigned used_locations = 0;
+
+ assert(sh->Type == GL_VERTEX_SHADER);
+
+ /* Operate in a total of three passes.
+ *
+ * 1. Invalidate the location assignments for all vertex shader inputs.
+ *
+ * 2. Assign locations for inputs that have user-defined (via
+ * glBindVertexAttribLocation) locatoins.
+ *
+ * 3. Assign locations to any inputs without assigned locations.
+ */
+
+ invalidate_variable_locations(sh, ir_var_in, VERT_ATTRIB_GENERIC0);
+
+ if (attrib != NULL) {
+ for (unsigned i = 0; i < attrib->NumParameters; i++) {
+ ir_variable *const var =
+ sh->symbols->get_variable(attrib->Parameters[i].Name);
+
+ if (var == NULL)
+ continue;
+
+ const int attr = attrib->Parameters[i].StateIndexes[0];
+
+ var->location = VERT_ATTRIB_GENERIC0 + attr;
+ used_locations |= (1 << attr);
+ }
+ }
+
+ foreach_list(node, &sh->ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ if ((var == NULL) || (var->mode != ir_var_in))
+ continue;
+
+ /* The location was explicitly assigned, nothing to do here.
+ */
+ if (var->location != -1)
+ continue;
+
+ /* Find an unused bit in used_locations and assign that as the
+ * attribute location.
+ */
+ for (unsigned i = 0; i < (8 * sizeof(used_locations)); i++) {
+ if ((used_locations & (1 << i)) == 0) {
+ var->location = VERT_ATTRIB_GENERIC0 + i;
+ used_locations |= (1 << i);
+ break;
+ }
+ }
+ }
+}
+
+
+void
link_shaders(struct glsl_program *prog)
{
prog->LinkStatus = false;
@@ -493,7 +572,9 @@
assign_uniform_locations(prog);
- /* FINISHME: Assign vertex shader input locations. */
+ if (prog->_LinkedShaders[0]->Type == GL_VERTEX_SHADER)
+ assign_attribute_locations(prog->_LinkedShaders[0],
+ prog->Attributes);
/* FINISHME: Assign vertex shader output / fragment shader input
* FINISHME: locations.