mesa: move vbo_count_tessellated_primitives() to api_validate.c

It's only used in this file and has nothing VBO-specific about it.

Reviewed-by: Roland Scheidegger <[email protected]>

1 files changed, 65 insertions, 3 deletions

diff --git a/src/mesa/main/api_validate.c b/src/mesa/main/api_validate.c
index 6ccb9e7ab21..7b91fdff55f 100644
--- a/src/mesa/main/api_validate.c
+++ b/src/mesa/main/api_validate.c
@@ -35,7 +35,6 @@
 #include "state.h"
 #include "transformfeedback.h"
 #include "uniforms.h"
-#include "vbo/vbo.h"
 #include "program/prog_print.h"
 
 
@@ -829,6 +828,69 @@ need_xfb_remaining_prims_check(const struct gl_context *ctx)
 }
 
 
+/**
+ * Figure out the number of transform feedback primitives that will be output
+ * considering the drawing mode, number of vertices, and instance count,
+ * assuming that no geometry shading is done and primitive restart is not
+ * used.
+ *
+ * This is used by driver back-ends in implementing the PRIMITIVES_GENERATED
+ * and TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN queries.  It is also used to
+ * pre-validate draw calls in GLES3 (where draw calls only succeed if there is
+ * enough room in the transform feedback buffer for the result).
+ */
+static size_t
+count_tessellated_primitives(GLenum mode, GLuint count, GLuint num_instances)
+{
+   size_t num_primitives;
+   switch (mode) {
+   case GL_POINTS:
+      num_primitives = count;
+      break;
+   case GL_LINE_STRIP:
+      num_primitives = count >= 2 ? count - 1 : 0;
+      break;
+   case GL_LINE_LOOP:
+      num_primitives = count >= 2 ? count : 0;
+      break;
+   case GL_LINES:
+      num_primitives = count / 2;
+      break;
+   case GL_TRIANGLE_STRIP:
+   case GL_TRIANGLE_FAN:
+   case GL_POLYGON:
+      num_primitives = count >= 3 ? count - 2 : 0;
+      break;
+   case GL_TRIANGLES:
+      num_primitives = count / 3;
+      break;
+   case GL_QUAD_STRIP:
+      num_primitives = count >= 4 ? ((count / 2) - 1) * 2 : 0;
+      break;
+   case GL_QUADS:
+      num_primitives = (count / 4) * 2;
+      break;
+   case GL_LINES_ADJACENCY:
+      num_primitives = count / 4;
+      break;
+   case GL_LINE_STRIP_ADJACENCY:
+      num_primitives = count >= 4 ? count - 3 : 0;
+      break;
+   case GL_TRIANGLES_ADJACENCY:
+      num_primitives = count / 6;
+      break;
+   case GL_TRIANGLE_STRIP_ADJACENCY:
+      num_primitives = count >= 6 ? (count - 4) / 2 : 0;
+      break;
+   default:
+      assert(!"Unexpected primitive type in count_tessellated_primitives");
+      num_primitives = 0;
+      break;
+   }
+   return num_primitives * num_instances;
+}
+
+
 static bool
 validate_draw_arrays(struct gl_context *ctx, const char *func,
                      GLenum mode, GLsizei count, GLsizei numInstances)
@@ -849,7 +911,7 @@ validate_draw_arrays(struct gl_context *ctx, const char *func,
    if (need_xfb_remaining_prims_check(ctx)) {
       struct gl_transform_feedback_object *xfb_obj
          = ctx->TransformFeedback.CurrentObject;
-      size_t prim_count = vbo_count_tessellated_primitives(mode, count, numInstances);
+      size_t prim_count = count_tessellated_primitives(mode, count, numInstances);
       if (xfb_obj->GlesRemainingPrims < prim_count) {
          _mesa_error(ctx, GL_INVALID_OPERATION,
                      "%s(exceeds transform feedback size)", func);
@@ -937,7 +999,7 @@ _mesa_validate_MultiDrawArrays(struct gl_context *ctx, GLenum mode,
       size_t xfb_prim_count = 0;
 
       for (i = 0; i < primcount; ++i)
-         xfb_prim_count += vbo_count_tessellated_primitives(mode, count[i], 1);
+         xfb_prim_count += count_tessellated_primitives(mode, count[i], 1);
 
       if (xfb_obj->GlesRemainingPrims < xfb_prim_count) {
          _mesa_error(ctx, GL_INVALID_OPERATION,