mesa: increase max texture image units and GLSL samplers to 16

The max texture coord units is still 8.  All the fixed-function paths are
still limited to 8 too.  But GLSL shaders can use more samplers now.

Note that some texcoord-related data structures are declared to be 16
elements in size rather than 8.  This just simplifies the code in a few
places; the extra elements aren't accessible to the user.

These changes haven't been extensively tested yet, but sanity checking has
been done.

It should be possible to increase the max image units/samplers to 32 without
doing anything special.  Beyond that we'll need longer bitfields in a few
places.

1 files changed, 92 insertions, 56 deletions

diff --git a/src/mesa/main/enable.c b/src/mesa/main/enable.c
index e0483a72e8..160a6fc086 100644
--- a/src/mesa/main/enable.c
+++ b/src/mesa/main/enable.c
@@ -201,6 +201,26 @@ _mesa_DisableClientState( GLenum cap )
    }
 
 
+
+/**
+ * Return pointer to current texture unit for setting/getting coordinate
+ * state.
+ * Note that we'll set GL_INVALID_OPERATION if the active texture unit is
+ * higher than the number of supported coordinate units.  And we'll return NULL.
+ */
+static struct gl_texture_unit *
+get_texcoord_unit(GLcontext *ctx)
+{
+   if (ctx->Texture.CurrentUnit >= ctx->Const.MaxTextureCoordUnits) {
+      _mesa_error(ctx, GL_INVALID_OPERATION, "glEnable/Disable(texcoord unit)");
+      return NULL;
+   }
+   else {
+      return &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
+   }
+}
+
+
 /**
  * Helper function to enable or disable a texture target.
  */
@@ -612,54 +632,62 @@ _mesa_set_enable(GLcontext *ctx, GLenum cap, GLboolean state)
             return;
          }
          break;
-      case GL_TEXTURE_GEN_Q: {
-         GLuint unit = ctx->Texture.CurrentUnit;
-         struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
-         GLuint newenabled = texUnit->TexGenEnabled & ~Q_BIT;
-         if (state)
-            newenabled |= Q_BIT;
-         if (texUnit->TexGenEnabled == newenabled)
-            return;
-         FLUSH_VERTICES(ctx, _NEW_TEXTURE);
-         texUnit->TexGenEnabled = newenabled;
+      case GL_TEXTURE_GEN_Q:
+         {
+            struct gl_texture_unit *texUnit = get_texcoord_unit(ctx);
+            if (texUnit) {
+               GLuint newenabled = texUnit->TexGenEnabled & ~Q_BIT;
+               if (state)
+                  newenabled |= Q_BIT;
+               if (texUnit->TexGenEnabled == newenabled)
+                  return;
+               FLUSH_VERTICES(ctx, _NEW_TEXTURE);
+               texUnit->TexGenEnabled = newenabled;
+            }
+         }
          break;
-      }
-      case GL_TEXTURE_GEN_R: {
-         GLuint unit = ctx->Texture.CurrentUnit;
-         struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
-         GLuint newenabled = texUnit->TexGenEnabled & ~R_BIT;
-         if (state)
-            newenabled |= R_BIT;
-         if (texUnit->TexGenEnabled == newenabled)
-            return;
-         FLUSH_VERTICES(ctx, _NEW_TEXTURE);
-         texUnit->TexGenEnabled = newenabled;
+      case GL_TEXTURE_GEN_R:
+         {
+            struct gl_texture_unit *texUnit = get_texcoord_unit(ctx);
+            if (texUnit) {
+               GLuint newenabled = texUnit->TexGenEnabled & ~R_BIT;
+               if (state)
+                  newenabled |= R_BIT;
+               if (texUnit->TexGenEnabled == newenabled)
+                  return;
+               FLUSH_VERTICES(ctx, _NEW_TEXTURE);
+               texUnit->TexGenEnabled = newenabled;
+            }
+         }
          break;
-      }
-      case GL_TEXTURE_GEN_S: {
-         GLuint unit = ctx->Texture.CurrentUnit;
-         struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
-         GLuint newenabled = texUnit->TexGenEnabled & ~S_BIT;
-         if (state)
-            newenabled |= S_BIT;
-         if (texUnit->TexGenEnabled == newenabled)
-            return;
-         FLUSH_VERTICES(ctx, _NEW_TEXTURE);
-         texUnit->TexGenEnabled = newenabled;
+      case GL_TEXTURE_GEN_S:
+         {
+            struct gl_texture_unit *texUnit = get_texcoord_unit(ctx);
+            if (texUnit) {
+               GLuint newenabled = texUnit->TexGenEnabled & ~S_BIT;
+               if (state)
+                  newenabled |= S_BIT;
+               if (texUnit->TexGenEnabled == newenabled)
+                  return;
+               FLUSH_VERTICES(ctx, _NEW_TEXTURE);
+               texUnit->TexGenEnabled = newenabled;
+            }
+         }
          break;
-      }
-      case GL_TEXTURE_GEN_T: {
-         GLuint unit = ctx->Texture.CurrentUnit;
-         struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
-         GLuint newenabled = texUnit->TexGenEnabled & ~T_BIT;
-         if (state)
-            newenabled |= T_BIT;
-         if (texUnit->TexGenEnabled == newenabled)
-            return;
-         FLUSH_VERTICES(ctx, _NEW_TEXTURE);
-         texUnit->TexGenEnabled = newenabled;
+      case GL_TEXTURE_GEN_T:
+         {
+            struct gl_texture_unit *texUnit = get_texcoord_unit(ctx);
+            if (texUnit) {
+               GLuint newenabled = texUnit->TexGenEnabled & ~T_BIT;
+               if (state)
+                  newenabled |= T_BIT;
+               if (texUnit->TexGenEnabled == newenabled)
+                  return;
+               FLUSH_VERTICES(ctx, _NEW_TEXTURE);
+               texUnit->TexGenEnabled = newenabled;
+            }
+         }
          break;
-      }
 
       /*
        * CLIENT STATE!!!
@@ -1153,28 +1181,36 @@ _mesa_IsEnabled( GLenum cap )
          return is_texture_enabled(ctx, TEXTURE_3D_BIT);
       case GL_TEXTURE_GEN_Q:
          {
-            const struct gl_texture_unit *texUnit;
-            texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
-            return (texUnit->TexGenEnabled & Q_BIT) ? GL_TRUE : GL_FALSE;
+            const struct gl_texture_unit *texUnit = get_texcoord_unit(ctx);
+            if (texUnit) {
+               return (texUnit->TexGenEnabled & Q_BIT) ? GL_TRUE : GL_FALSE;
+            }
          }
+         return GL_FALSE;
       case GL_TEXTURE_GEN_R:
          {
-            const struct gl_texture_unit *texUnit;
-            texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
-            return (texUnit->TexGenEnabled & R_BIT) ? GL_TRUE : GL_FALSE;
+            const struct gl_texture_unit *texUnit = get_texcoord_unit(ctx);
+            if (texUnit) {
+               return (texUnit->TexGenEnabled & R_BIT) ? GL_TRUE : GL_FALSE;
+            }
          }
+         return GL_FALSE;
       case GL_TEXTURE_GEN_S:
          {
-            const struct gl_texture_unit *texUnit;
-            texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
-            return (texUnit->TexGenEnabled & S_BIT) ? GL_TRUE : GL_FALSE;
+            const struct gl_texture_unit *texUnit = get_texcoord_unit(ctx);
+            if (texUnit) {
+               return (texUnit->TexGenEnabled & S_BIT) ? GL_TRUE : GL_FALSE;
+            }
          }
+         return GL_FALSE;
       case GL_TEXTURE_GEN_T:
          {
-            const struct gl_texture_unit *texUnit;
-            texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
-            return (texUnit->TexGenEnabled & T_BIT) ? GL_TRUE : GL_FALSE;
+            const struct gl_texture_unit *texUnit = get_texcoord_unit(ctx);
+            if (texUnit) {
+               return (texUnit->TexGenEnabled & T_BIT) ? GL_TRUE : GL_FALSE;
+            }
          }
+         return GL_FALSE;
 
       /*
        * CLIENT STATE!!!