Mesa (master): mesa: Follow OpenGL conversion rules for values that exceed storage size

[GitLab Mirror]

Module: Mesa
Branch: master
Commit: 35ee6b3d361b13c6380cf357ef05c9681639cfc1
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=35ee6b3d361b13c6380cf357ef05c9681639cfc1

Author: Dylan Baker <dylan at pnwbakers.com>
Date:   Tue Apr 21 23:32:45 2020 -0700

mesa: Follow OpenGL conversion rules for values that exceed storage size

Section 2.2.2 (Data Conversions For State Query Commands) of the
OpenGL 4.5 spec says:

  Following these steps, if a value is so large in magnitude that
  it cannot be represented by the returned data type, then the
  nearest value representable using that type is returned.

The current code doesn't do the correct thing, because it truncates a
long (potentially a 64bit values) to an int.

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/2828
Fixes: 53c36dfcfe3eb3749a53267f054870280afb0d71
       ("replace IROUND with util functions")

Reviewed-by: Matt Turner <mattst88 at gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4673>

---

 src/mesa/main/texparam.c | 37 +++++++++++++++++++++++++++++++++----
 1 file changed, 33 insertions(+), 4 deletions(-)

diff --git a/src/mesa/main/texparam.c b/src/mesa/main/texparam.c
index 7e062403bb9..ae3fa825a4f 100644
--- a/src/mesa/main/texparam.c
+++ b/src/mesa/main/texparam.c
@@ -45,6 +45,7 @@
 #include "main/teximage.h"
 #include "main/texstate.h"
 #include "program/prog_instruction.h"
+#include "util/u_math.h"
 
 
 /**
@@ -2423,16 +2424,30 @@ get_tex_parameteriv(struct gl_context *ctx,
             goto invalid_pname;
          /* GL spec 'Data Conversions' section specifies that floating-point
           * value in integer Get function is rounded to nearest integer
+          *
+          * Section 2.2.2 (Data Conversions For State Query Commands) of the
+          * OpenGL 4.5 spec says:
+          *
+          *   Following these steps, if a value is so large in magnitude that
+          *   it cannot be represented by the returned data type, then the
+          *   nearest value representable using that type is returned.
           */
-         *params = lroundf(obj->Sampler.MinLod);
+         *params = CLAMP(lroundf(obj->Sampler.MinLod), INT_MIN, INT_MAX);
          break;
       case GL_TEXTURE_MAX_LOD:
          if (!_mesa_is_desktop_gl(ctx) && !_mesa_is_gles3(ctx))
             goto invalid_pname;
          /* GL spec 'Data Conversions' section specifies that floating-point
           * value in integer Get function is rounded to nearest integer
+          *
+          * Section 2.2.2 (Data Conversions For State Query Commands) of the
+          * OpenGL 4.5 spec says:
+          *
+          *   Following these steps, if a value is so large in magnitude that
+          *   it cannot be represented by the returned data type, then the
+          *   nearest value representable using that type is returned.
           */
-         *params = lroundf(obj->Sampler.MaxLod);
+         *params = CLAMP(lroundf(obj->Sampler.MaxLod), INT_MIN, INT_MAX);
          break;
       case GL_TEXTURE_BASE_LEVEL:
          if (!_mesa_is_desktop_gl(ctx) && !_mesa_is_gles3(ctx))
@@ -2448,8 +2463,15 @@ get_tex_parameteriv(struct gl_context *ctx,
             goto invalid_pname;
          /* GL spec 'Data Conversions' section specifies that floating-point
           * value in integer Get function is rounded to nearest integer
+          *
+          * Section 2.2.2 (Data Conversions For State Query Commands) of the
+          * OpenGL 4.5 spec says:
+          *
+          *   Following these steps, if a value is so large in magnitude that
+          *   it cannot be represented by the returned data type, then the
+          *   nearest value representable using that type is returned.
           */
-         *params = lroundf(obj->Sampler.MaxAnisotropy);
+         *params = CLAMP(lroundf(obj->Sampler.MaxAnisotropy), INT_MIN, INT_MAX);
          break;
       case GL_GENERATE_MIPMAP_SGIS:
          if (ctx->API != API_OPENGL_COMPAT && ctx->API != API_OPENGLES)
@@ -2486,8 +2508,15 @@ get_tex_parameteriv(struct gl_context *ctx,
 
          /* GL spec 'Data Conversions' section specifies that floating-point
           * value in integer Get function is rounded to nearest integer
+          *
+          * Section 2.2.2 (Data Conversions For State Query Commands) of the
+          * OpenGL 4.5 spec says:
+          *
+          *   Following these steps, if a value is so large in magnitude that
+          *   it cannot be represented by the returned data type, then the
+          *   nearest value representable using that type is returned.
           */
-         *params = lroundf(obj->Sampler.LodBias);
+         *params = CLAMP(lroundf(obj->Sampler.LodBias), INT_MIN, INT_MAX);
          break;
       case GL_TEXTURE_CROP_RECT_OES:
          if (ctx->API != API_OPENGLES || !ctx->Extensions.OES_draw_texture)