[Mesa-dev] [PATCH 04/13] mesa: decrease the array size of ctx->Texture.FixedFuncUnit to 8

Marek Olšák maraeo at gmail.com
Fri Feb 9 01:18:39 UTC 2018


From: Marek Olšák <marek.olsak at amd.com>

GL allows doing glTexEnv on 192 texture units, while in reality,
only MaxTextureCoordUnits units are used by fixed-func shaders.

There is a piglit patch that adjusts piglits/texunits to check only
MaxTextureCoordUnits units.
---
 src/mesa/main/enable.c   |  5 +++++
 src/mesa/main/mtypes.h   |  2 +-
 src/mesa/main/texenv.c   | 27 +++++++++++++++++++++++++++
 src/mesa/main/texstate.c |  2 +-
 src/mesa/main/texstate.h |  3 +++
 5 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/src/mesa/main/enable.c b/src/mesa/main/enable.c
index 4c5f9dc..f811ab5 100644
--- a/src/mesa/main/enable.c
+++ b/src/mesa/main/enable.c
@@ -202,20 +202,22 @@ get_texcoord_unit(struct gl_context *ctx)
 /**
  * Helper function to enable or disable a texture target.
  * \param bit  one of the TEXTURE_x_BIT values
  * \return GL_TRUE if state is changing or GL_FALSE if no change
  */
 static GLboolean
 enable_texture(struct gl_context *ctx, GLboolean state, GLbitfield texBit)
 {
    struct gl_fixedfunc_texture_unit *texUnit =
       _mesa_get_current_fixedfunc_tex_unit(ctx);
+   if (!texUnit)
+      return false;
 
    const GLbitfield newenabled = state
       ? (texUnit->Enabled | texBit) : (texUnit->Enabled & ~texBit);
 
    if (texUnit->Enabled == newenabled)
        return GL_FALSE;
 
    FLUSH_VERTICES(ctx, _NEW_TEXTURE_STATE);
    texUnit->Enabled = newenabled;
    return GL_TRUE;
@@ -1286,20 +1288,23 @@ _mesa_IsEnabledi( GLenum cap, GLuint index )
 
 /**
  * Helper function to determine whether a texture target is enabled.
  */
 static GLboolean
 is_texture_enabled(struct gl_context *ctx, GLbitfield bit)
 {
    const struct gl_fixedfunc_texture_unit *const texUnit =
       _mesa_get_current_fixedfunc_tex_unit(ctx);
 
+   if (!texUnit)
+      return false;
+
    return (texUnit->Enabled & bit) ? GL_TRUE : GL_FALSE;
 }
 
 
 /**
  * Return simple enable/disable state.
  *
  * \param cap  state variable to query.
  *
  * Returns the state of the specified capability from the current GL context.
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 562fb17..3a4fdb5 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -1363,21 +1363,21 @@ struct gl_texture_attrib
    /** Bitwise-OR of all Texture.Unit[i]._GenFlags */
    GLbitfield _GenFlags;
 
    /** Largest index of a texture unit with _Current != NULL. */
    GLint _MaxEnabledTexImageUnit;
 
    /** Largest index + 1 of texture units that have had any CurrentTex set. */
    GLint NumCurrentTexUsed;
 
    struct gl_texture_unit Unit[MAX_COMBINED_TEXTURE_IMAGE_UNITS];
-   struct gl_fixedfunc_texture_unit FixedFuncUnit[MAX_COMBINED_TEXTURE_IMAGE_UNITS];
+   struct gl_fixedfunc_texture_unit FixedFuncUnit[MAX_TEXTURE_COORD_UNITS];
 };
 
 
 /**
  * Data structure representing a single clip plane (e.g. one of the elements
  * of the ctx->Transform.EyeUserPlane or ctx->Transform._ClipUserPlane array).
  */
 typedef GLfloat gl_clip_plane[4];
 
 
diff --git a/src/mesa/main/texenv.c b/src/mesa/main/texenv.c
index 9018ce9..22fc8da 100644
--- a/src/mesa/main/texenv.c
+++ b/src/mesa/main/texenv.c
@@ -393,20 +393,29 @@ _mesa_TexEnvfv( GLenum target, GLenum pname, const GLfloat *param )
       ? ctx->Const.MaxTextureCoordUnits : ctx->Const.MaxCombinedTextureImageUnits;
    if (ctx->Texture.CurrentUnit >= maxUnit) {
       _mesa_error(ctx, GL_INVALID_OPERATION, "glTexEnvfv(current unit)");
       return;
    }
 
    if (target == GL_TEXTURE_ENV) {
       struct gl_fixedfunc_texture_unit *texUnit =
          _mesa_get_current_fixedfunc_tex_unit(ctx);
 
+      /* The GL spec says that we should report an error if the unit is greater
+       * than GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, but in practice, only
+       * fixed-function units are usable. This is probably a spec bug.
+       * Ignore glTexEnv(GL_TEXTURE_ENV) calls for non-fixed-func units,
+       * because we don't want to process calls that have no effect.
+       */
+      if (!texUnit)
+         return;
+
       switch (pname) {
       case GL_TEXTURE_ENV_MODE:
          set_env_mode(ctx, texUnit, (GLenum) iparam0);
          break;
       case GL_TEXTURE_ENV_COLOR:
          set_env_color(ctx, texUnit, param);
          break;
       case GL_COMBINE_RGB:
       case GL_COMBINE_ALPHA:
          set_combiner_mode(ctx, texUnit, pname, (GLenum) iparam0);
@@ -642,20 +651,29 @@ _mesa_GetTexEnvfv( GLenum target, GLenum pname, GLfloat *params )
       ? ctx->Const.MaxTextureCoordUnits : ctx->Const.MaxCombinedTextureImageUnits;
    if (ctx->Texture.CurrentUnit >= maxUnit) {
       _mesa_error(ctx, GL_INVALID_OPERATION, "glGetTexEnvfv(current unit)");
       return;
    }
 
    if (target == GL_TEXTURE_ENV) {
       struct gl_fixedfunc_texture_unit *texUnit =
          _mesa_get_current_fixedfunc_tex_unit(ctx);
 
+      /* The GL spec says that we should report an error if the unit is greater
+       * than GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, but in practice, only
+       * fixed-function units are usable. This is probably a spec bug.
+       * Ignore calls for non-fixed-func units, because we don't process
+       * glTexEnv for them either.
+       */
+      if (!texUnit)
+         return;
+
       if (pname == GL_TEXTURE_ENV_COLOR) {
          if(ctx->NewState & (_NEW_BUFFERS | _NEW_FRAG_CLAMP))
             _mesa_update_state(ctx);
          if (_mesa_get_clamp_fragment_color(ctx, ctx->DrawBuffer))
             COPY_4FV( params, texUnit->EnvColor );
          else
             COPY_4FV( params, texUnit->EnvColorUnclamped );
       }
       else {
          GLint val = get_texenvi(ctx, texUnit, pname);
@@ -710,20 +728,29 @@ _mesa_GetTexEnviv( GLenum target, GLenum pname, GLint *params )
       ? ctx->Const.MaxTextureCoordUnits : ctx->Const.MaxCombinedTextureImageUnits;
    if (ctx->Texture.CurrentUnit >= maxUnit) {
       _mesa_error(ctx, GL_INVALID_OPERATION, "glGetTexEnviv(current unit)");
       return;
    }
 
    if (target == GL_TEXTURE_ENV) {
       struct gl_fixedfunc_texture_unit *texUnit =
          _mesa_get_current_fixedfunc_tex_unit(ctx);
 
+      /* The GL spec says that we should report an error if the unit is greater
+       * than GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, but in practice, only
+       * fixed-function units are usable. This is probably a spec bug.
+       * Ignore calls for non-fixed-func units, because we don't process
+       * glTexEnv for them either.
+       */
+      if (!texUnit)
+         return;
+
       if (pname == GL_TEXTURE_ENV_COLOR) {
          params[0] = FLOAT_TO_INT( texUnit->EnvColor[0] );
          params[1] = FLOAT_TO_INT( texUnit->EnvColor[1] );
          params[2] = FLOAT_TO_INT( texUnit->EnvColor[2] );
          params[3] = FLOAT_TO_INT( texUnit->EnvColor[3] );
       }
       else {
          GLint val = get_texenvi(ctx, texUnit, pname);
          if (val >= 0) {
             *params = val;
diff --git a/src/mesa/main/texstate.c b/src/mesa/main/texstate.c
index 2b05630..f9f50a3 100644
--- a/src/mesa/main/texstate.c
+++ b/src/mesa/main/texstate.c
@@ -96,21 +96,21 @@ _mesa_copy_texture_state( const struct gl_context *src, struct gl_context *dst )
             if (src->Texture.Unit[u].CurrentTex[tex]) {
                dst->Texture.NumCurrentTexUsed =
                   MAX2(dst->Texture.NumCurrentTexUsed, u + 1);
             }
          }
          dst->Texture.Unit[u]._BoundTextures = src->Texture.Unit[u]._BoundTextures;
          _mesa_unlock_context_textures(dst);
       }
    }
 
-   for (u = 0; u < src->Const.MaxCombinedTextureImageUnits; u++) {
+   for (u = 0; u < src->Const.MaxTextureCoordUnits; u++) {
       dst->Texture.FixedFuncUnit[u].Enabled = src->Texture.FixedFuncUnit[u].Enabled;
       dst->Texture.FixedFuncUnit[u].EnvMode = src->Texture.FixedFuncUnit[u].EnvMode;
       COPY_4V(dst->Texture.FixedFuncUnit[u].EnvColor, src->Texture.FixedFuncUnit[u].EnvColor);
       dst->Texture.FixedFuncUnit[u].TexGenEnabled = src->Texture.FixedFuncUnit[u].TexGenEnabled;
       dst->Texture.FixedFuncUnit[u].GenS = src->Texture.FixedFuncUnit[u].GenS;
       dst->Texture.FixedFuncUnit[u].GenT = src->Texture.FixedFuncUnit[u].GenT;
       dst->Texture.FixedFuncUnit[u].GenR = src->Texture.FixedFuncUnit[u].GenR;
       dst->Texture.FixedFuncUnit[u].GenQ = src->Texture.FixedFuncUnit[u].GenQ;
 
       /* GL_EXT_texture_env_combine */
diff --git a/src/mesa/main/texstate.h b/src/mesa/main/texstate.h
index cf3f7e5..c0b73b1 100644
--- a/src/mesa/main/texstate.h
+++ b/src/mesa/main/texstate.h
@@ -58,20 +58,23 @@ _mesa_get_current_tex_unit(struct gl_context *ctx)
 /**
  * Return pointer to current fixed-func texture unit.
  * This the texture unit set by glActiveTexture(), not glClientActiveTexture().
  * \return NULL if the current unit is not a fixed-func texture unit
  */
 static inline struct gl_fixedfunc_texture_unit *
 _mesa_get_current_fixedfunc_tex_unit(struct gl_context *ctx)
 {
    unsigned unit = ctx->Texture.CurrentUnit;
 
+   if (unit >= ARRAY_SIZE(ctx->Texture.FixedFuncUnit))
+      return NULL;
+
    return &ctx->Texture.FixedFuncUnit[unit];
 }
 
 
 static inline GLuint
 _mesa_max_tex_unit(struct gl_context *ctx)
 {
    /* See OpenGL spec for glActiveTexture: */
    return MAX2(ctx->Const.MaxCombinedTextureImageUnits,
                ctx->Const.MaxTextureCoordUnits);
-- 
2.7.4



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