# GraphicsStateGuardian

from pandac.PandaModules import GraphicsStateGuardian

Class : GraphicsStateGuardian
Description : Encapsulates all the communication with a particular instance of a given rendering backend. Tries to guarantee that redundant state-change requests are not issued (hence "state guardian").
There will be one of these objects for each different graphics context active in the system.

## Inheritance:

GraphicsStateGuardian: GraphicsStateGuardianBase
GraphicsStateGuardianBase: TypedWritableReferenceCount
TypedWritableReferenceCount: TypedWritable ReferenceCount
TypedWritable: TypedObject
TypedObject: MemoryBase
MemoryBase:
ReferenceCount: MemoryBase

## Methods of GraphicsStateGuardian:

beginScene
clearFlashTexture
endScene
getAlphaScaleTextureStage
getAlphaScaleViaTexture
getClassType
getColorScaleViaLighting
getCoordinateSystem
getCopyTextureInverted
getEngine
getFlashTexture
getGamma
getInternalCoordinateSystem
getLoader
getMax3dTextureDimension
getMaxClipPlanes
getMaxCubeMapDimension
getMaximumSimultaneousRenderTargets
getMaxLights
getMaxTextureStages
getMaxVertexTransformIndices
getMaxVertexTransforms
getPipe
getPreparedObjects
getPreparedTextures
getRuntimeColorScale
getScene
getShaderModel
getSupports3dTexture
getSupportsBasicShaders
getSupportsCompressedTexture
getSupportsCubeMap
getSupportsDepthStencil
getSupportsDepthTexture
getSupportsGenerateMipmap
getSupportsRenderTexture
getSupportsShadowFilter
getSupportsStencil
getSupportsTexNonPow2
getSupportsTextureCombine
getSupportsTextureDot3
getSupportsTextureSavedResult
getSupportsTwoSidedStencil
getTextureQualityOverride
getThreadingModel
isActive
isHardware
isValid
needsReset
releaseAll
releaseAllGeoms
releaseAllIndexBuffers
releaseAllTextures
releaseAllVertexBuffers
restoreGamma
setActive
setCoordinateSystem
setFlashTexture
setGamma
setIncompleteRender
setLoader
setScene
setShaderModel
setTextureQualityOverride
traversePreparedTextures

## Methods of GraphicsStateGuardianBase:

getClassType
getDefaultGsg
getEffectiveIncompleteRender
getGsg
getIncompleteRender
getMaxTextureDimension
getMaxVerticesPerArray
getMaxVerticesPerPrimitive
getNumGsgs
getSupportedGeomRendering
getSupportsCompressedTextureFormat
getSupportsMultisample
getSupportsOcclusionQuery
prefersTriangleStrips
setDefaultGsg

## Methods of TypedWritableReferenceCount:

getClassType

## Methods of TypedWritable:

getClassType

## Methods of TypedObject:

getClassType
getType
getTypeIndex
isExactType
isOfType

## Methods of ReferenceCount:

getClassType
getRefCount
ref
testRefCountIntegrity
testRefCountNonzero
unref

## Constants in GraphicsStateGuardian:

SM00 | (ShaderModel)
SM11 | (ShaderModel)
SM20 | (ShaderModel)
SM2X | (ShaderModel)
SM30 | (ShaderModel)
SM40 | (ShaderModel)

beginScene virtual bool GraphicsStateGuardian::begin_scene(void); Description: Called between begin_frame() and end_frame() to mark the beginning of drawing commands for a "scene" (usually a particular DisplayRegion) within a frame. All 3-D drawing commands, except the clear operation, must be enclosed within begin_scene() .. end_scene(). This must be called in the draw thread. The return value is true if successful (in which case the scene will be drawn and end_scene() will be called later), or false if unsuccessful (in which case nothing will be drawn and end_scene() will not be called).

clearFlashTexture void GraphicsStateGuardian::clear_flash_texture(void); Description: Resets the "flash texture", so that no textures will flash. See set_flash_texture().

endScene virtual void GraphicsStateGuardian::end_scene(void); Description: Called between begin_frame() and end_frame() to mark the end of drawing commands for a "scene" (usually a particular DisplayRegion) within a frame. All 3-D drawing commands, except the clear operation, must be enclosed within begin_scene() .. end_scene().

getAlphaScaleTextureStage static TextureStage *GraphicsStateGuardian::get_alpha_scale_texture_stage(void); Description: Returns the TextureStage that will be used to apply an alpha scale, if get_alpha_scale_via_texture() returns true.

getAlphaScaleViaTexture bool GraphicsStateGuardian::get_alpha_scale_via_texture(void) const; Description: Returns true if this particular GSG can implement (or would prefer to implement) an alpha scale via an additional Texture layer, or false if we need to actually munge the alpha. Description: This variant of get_alpha_scale_via_texture() answers the question of whether the GSG can implement an alpha scale via an additional Texture layer, considering the current TextureAttrib that will be in effect. This considers whether there is at least one additional texture slot available on the GSG.

getClassType static TypeHandle GraphicsStateGuardian::get_class_type(void); Undocumented function.

getColorScaleViaLighting bool GraphicsStateGuardian::get_color_scale_via_lighting(void) const; Description: Returns true if this particular GSG can implement (or would prefer to implement) set color and/or color scale using materials and/or ambient lights, or false if we need to actually munge the color.

getCoordinateSystem CoordinateSystem GraphicsStateGuardian::get_coordinate_system(void) const; Description: Returns the coordinate system in effect on this particular gsg. Normally, this will be the default coordinate system, but it might be set differently at runtime.

getCopyTextureInverted bool GraphicsStateGuardian::get_copy_texture_inverted(void) const; Description: Returns true if this particular GSG has the property that any framebuffer-to-texture copy results in a texture that is upside-down and backwards from Panda's usual convention; that is, it copies into a texture from the bottom up instead of from the top down. If this is true, then on offscreen GraphicsBuffer created for the purposes of rendering into a texture should be created with the invert flag set true, to compensate. Panda will do this automatically if you create an offscreen buffer using GraphicsOutput::make_texture_buffer().

getEngine GraphicsEngine *GraphicsStateGuardian::get_engine(void) const; Description: Returns the graphics engine that created this GSG. Since there is normally only one GraphicsEngine object in an application, this is usually the same as the global GraphicsEngine.

getFlashTexture Texture *GraphicsStateGuardian::get_flash_texture(void) const; Description: Returns the current "flash texture", if any, or NULL if none. See set_flash_texture().

getGamma float GraphicsStateGuardian::get_gamma(float gamma); Description: Get the current gamma setting.

getInternalCoordinateSystem virtual CoordinateSystem GraphicsStateGuardian::get_internal_coordinate_system(void) const; Description: Returns the coordinate system used internally by the GSG. This may be the same as the external coordinate system reported by get_coordinate_system(), or it may be something different. In any case, vertices that have been transformed before being handed to the GSG (that is, vertices with a contents value of C_clip_point) will be expected to be in this coordinate system.

getLoader Loader *GraphicsStateGuardian::get_loader(void) const; Description: Returns the Loader object that will be used by this GSG to load textures when necessary, if get_incomplete_render() is true.

getMax3dTextureDimension int GraphicsStateGuardian::get_max_3d_texture_dimension(void) const; Description: Returns the largest possible texture size in any one dimension for a 3-d texture, or -1 if there is no particular limit. Returns 0 if 3-d textures are not supported. The value returned may not be meaningful until after the graphics context has been fully created (e.g. the window has been opened).

getMaxClipPlanes int GraphicsStateGuardian::get_max_clip_planes(void) const; Description: Returns the maximum number of simultaneous clip planes that may be applied to geometry, or -1 if there is no particular limit. The value returned may not be meaningful until after the graphics context has been fully created (e.g. the window has been opened).

getMaxCubeMapDimension int GraphicsStateGuardian::get_max_cube_map_dimension(void) const; Description: Returns the largest possible texture size in any one dimension for a cube map texture, or -1 if there is no particular limit. Returns 0 if cube map textures are not supported. The value returned may not be meaningful until after the graphics context has been fully created (e.g. the window has been opened).

getMaximumSimultaneousRenderTargets int GraphicsStateGuardian::get_maximum_simultaneous_render_targets(void) const; Description: Returns the maximum simultaneous render targets supported.

getMaxLights int GraphicsStateGuardian::get_max_lights(void) const; Description: Returns the maximum number of simultaneous lights that may be rendered on geometry, or -1 if there is no particular limit. The value returned may not be meaningful until after the graphics context has been fully created (e.g. the window has been opened).

getMaxTextureStages int GraphicsStateGuardian::get_max_texture_stages(void) const; Description: Returns the maximum number of simultaneous textures that may be applied to geometry with multitexturing, as supported by this particular GSG. If you exceed this number, the lowest-priority texture stages will not be applied. Use TextureStage::set_priority() to adjust the relative importance of the different texture stages. The value returned may not be meaningful until after the graphics context has been fully created (e.g. the window has been opened).

getMaxVertexTransformIndices int GraphicsStateGuardian::get_max_vertex_transform_indices(void) const; Description: Returns the maximum number of transforms there may be in a single TransformTable for this graphics hardware. If this number is 0 (but get_max_transforms() is nonzero), then the graphics hardware (or API) doesn't support indexed transforms, but can support direct transform references. The value returned may not be meaningful until after the graphics context has been fully created (e.g. the window has been opened).

getMaxVertexTransforms int GraphicsStateGuardian::get_max_vertex_transforms(void) const; Description: Returns the maximum number of transform matrices that may be simultaneously used to transform any one vertex by the graphics hardware. If this number is 0, then the hardware (or the graphics backend) doesn't support soft-skinned vertices (in which case Panda will animate the vertices in software). The value returned may not be meaningful until after the graphics context has been fully created (e.g. the window has been opened).

getPipe GraphicsPipe *GraphicsStateGuardian::get_pipe(void) const; Description: Returns the graphics pipe on which this GSG was created.

getPreparedObjects virtual PreparedGraphicsObjects *GraphicsStateGuardian::get_prepared_objects(void); Description: Returns the set of texture and geom objects that have been prepared with this GSG (and possibly other GSG's that share objects).

getPreparedTextures PyObject *GraphicsStateGuardian::get_prepared_textures(void) const; Description: Returns a Python list of all of the currently-prepared textures within the GSG.

getRuntimeColorScale bool GraphicsStateGuardian::get_runtime_color_scale(void) const; Description: Returns true if this particular GSG can implement (or would prefer to implement) set color and/or color scale directly, without requiring any munging of vertices or tricks with lighting.

getScene virtual SceneSetup *GraphicsStateGuardian::get_scene(void) const; Description: Returns the current SceneSetup object.

getShaderModel int GraphicsStateGuardian::get_shader_model(void) const; Description: Returns the ShaderModel

getSupports3dTexture bool GraphicsStateGuardian::get_supports_3d_texture(void) const; Description: Returns true if this GSG can render 3-d (volumetric) textures.

getSupportsBasicShaders bool GraphicsStateGuardian::get_supports_basic_shaders(void) const; Description: Returns true if this particular GSG supports arbfp1+arbvp1 or above.

getSupportsCompressedTexture bool GraphicsStateGuardian::get_supports_compressed_texture(void) const; Description: Returns true if this GSG can compress textures as it loads them into texture memory, and/or accept pre-compressed textures for storing.

getSupportsCubeMap bool GraphicsStateGuardian::get_supports_cube_map(void) const; Description: Returns true if this GSG can render cube map textures.

getSupportsDepthStencil bool GraphicsStateGuardian::get_supports_depth_stencil(void) const; Description: Returns true if this particular GSG supports textures whose format is F_depth_stencil. This only returns true if the GSG supports the full packed depth-stencil functionality.

getSupportsDepthTexture bool GraphicsStateGuardian::get_supports_depth_texture(void) const; Description: Returns true if this particular GSG supports textures whose format is F_depth_stencil. This returns true if the GSG supports GL_DEPTH_COMPONENT textures, which are considered a limited but still valid case of F_depth_stencil.

getSupportsGenerateMipmap bool GraphicsStateGuardian::get_supports_generate_mipmap(void) const; Description: Returns true if this particular GSG can generate mipmaps for a texture automatically, or if they must be generated in software. If this is true, then mipmaps can safely be enabled for rendered textures (e.g. using the MultitexReducer).

getSupportsRenderTexture bool GraphicsStateGuardian::get_supports_render_texture(void) const; Description: Returns true if this particular GSG can render directly into a texture, or false if it must always copy-to-texture at the end of each frame to achieve this effect.

getSupportsShadowFilter bool GraphicsStateGuardian::get_supports_shadow_filter(void) const; Description: Returns true if this particular GSG supports the filter mode FT_shadow for depth textures.

getSupportsStencil bool GraphicsStateGuardian::get_supports_stencil(void) const; Description: Returns true if this particular GSG supports stencil buffers at all.

getSupportsTexNonPow2 bool GraphicsStateGuardian::get_supports_tex_non_pow2(void) const; Description: Returns true if this GSG can handle non power of two sized textures.

getSupportsTextureCombine bool GraphicsStateGuardian::get_supports_texture_combine(void) const; Description: Returns true if this particular GSG can use the TextureStage::M_combine mode, which includes all of the texture blend modes specified by set_combine_rgb() and/or set_combine_alpha(). If this is false, you must limit yourself to using the simpler blend modes.

getSupportsTextureDot3 bool GraphicsStateGuardian::get_supports_texture_dot3(void) const; Description: Returns true if this GSG can use the TextureStage::CM_dot3_rgb or CM_dot3_rgba combine modes.

getSupportsTextureSavedResult bool GraphicsStateGuardian::get_supports_texture_saved_result(void) const; Description: Returns true if this GSG can use the TextureStage::CS_last_saved_result source, which allows you to save the result of a TextureStage and re-use it for multiple inputs.

getSupportsTwoSidedStencil bool GraphicsStateGuardian::get_supports_two_sided_stencil(void) const; Description: Returns true if this particular GSG supports two sided stencil: different stencil settings for the front and back side of the same polygon.

getTextureQualityOverride Texture::QualityLevel GraphicsStateGuardian::get_texture_quality_override(void) const; Description: Returns the global quality_level override specified by set_texture_quality_override. This is mainly useful for the tinydisplay software renderer. See Texture::set_quality_level().

getThreadingModel GraphicsThreadingModel const &GraphicsStateGuardian::get_threading_model(void) const; Description: Returns the threading model that was used to create this GSG.

isActive bool GraphicsStateGuardian::is_active(void) const; Description: Returns the active flag associated with the GraphicsStateGuardian.

isHardware bool GraphicsStateGuardian::is_hardware(void) const; Description: Returns true if this GSG appears to be hardware-accelerated, or false if it is known to be software only.

isValid bool GraphicsStateGuardian::is_valid(void) const; Description: Returns true if the GSG has been correctly initialized within a graphics context, false if there has been some problem or it hasn't been initialized yet.

needsReset bool GraphicsStateGuardian::needs_reset(void) const; Description: Returns true if the gsg is marked as needing a reset.

releaseAll void GraphicsStateGuardian::release_all(void); Description: Releases all prepared objects.

releaseAllGeoms int GraphicsStateGuardian::release_all_geoms(void); Description: Frees the resources for all geoms associated with this GSG.

releaseAllIndexBuffers int GraphicsStateGuardian::release_all_index_buffers(void); Description: Frees the resources for all index buffers associated with this GSG.

releaseAllTextures int GraphicsStateGuardian::release_all_textures(void); Description: Frees the resources for all textures associated with this GSG.

releaseAllVertexBuffers int GraphicsStateGuardian::release_all_vertex_buffers(void); Description: Frees the resources for all vertex buffers associated with this GSG.

restoreGamma virtual void GraphicsStateGuardian::restore_gamma(void); Description: Restore original gamma setting.

setActive void GraphicsStateGuardian::set_active(bool active); Description: Sets the active flag associated with the GraphicsStateGuardian. If the GraphicsStateGuardian is marked inactive, nothing is rendered. This is not normally turned off unless there is a problem with the rendering detected at a low level.

setCoordinateSystem void GraphicsStateGuardian::set_coordinate_system(CoordinateSystem cs); Description: Changes the coordinate system in effect on this particular gsg. This is also called the "external" coordinate system, since it is the coordinate system used by the scene graph, external to to GSG. Normally, this will be the default coordinate system, but it might be set differently at runtime.

setFlashTexture void GraphicsStateGuardian::set_flash_texture(Texture *tex); Description: Sets the "flash texture". This is a debug feature; when enabled, the specified texture will begin flashing in the scene, helping you to find it visually. The texture also flashes with a color code: blue for mipmap level 0, yellow for mipmap level 1, and red for mipmap level 2 or higher (even for textures that don't have mipmaps). This gives you an idea of the choice of the texture size. If it is blue, the texture is being drawn the proper size or magnified; if it is yellow, it is being minified a little bit; and if it red, it is being minified considerably. If you see a red texture when you are right in front of it, you should consider reducing the size of the texture to avoid wasting texture memory. Not all rendering backends support the flash_texture feature. Presently, it is only supported by OpenGL.

setGamma virtual bool GraphicsStateGuardian::set_gamma(float gamma); Description: Set gamma. Returns true on success.

setIncompleteRender void GraphicsStateGuardian::set_incomplete_render(bool incomplete_render); Description: Sets the incomplete_render flag. When this is true, the frame will be rendered even if some of the geometry or textures in the scene are not available (e.g. they have been temporarily paged out). When this is false, the frame will be held up while this data is reloaded. Setting this true allows for a smoother frame rate, but occasionally parts of the frame will be invisible or missing (they will generally come in within a second or two). Setting this false guarantees that every frame will be complete, but may cause more chugs as things are loaded up at runtime. You may want to set this false during loading screens, to guarantee that all of your assets are available by the time you take the loading screen down. This flag may also be set individually on each DisplayRegion. It will be considered true for a given DisplayRegion only if it is true on both the GSG and on the DisplayRegion.

setLoader void GraphicsStateGuardian::set_loader(Loader *loader); Description: Sets the Loader object that will be used by this GSG to load textures when necessary, if get_incomplete_render() is true.

setScene bool GraphicsStateGuardian::set_scene(SceneSetup *scene_setup); NDEBUG Description: Sets the SceneSetup object that indicates the initial camera position, etc. This must be called before traversal begins. Returns true if the scene is acceptable, false if something's wrong. This should be called in the draw thread only.

setShaderModel void GraphicsStateGuardian::set_shader_model(int shader_model); Description: Sets the ShaderModel. This will override the auto- detected shader model during GSG reset. Useful for testing lower-end shaders.

setTextureQualityOverride void GraphicsStateGuardian::set_texture_quality_override(Texture::QualityLevel quality_level); Description: Specifies the global quality_level to be imposed for all Textures rendered by this GSG. This overrides the value set on individual textures via Texture::set_quality_level(). Set this to Texture::QL_default in order to allow the individual texture quality levels to be respected. This is mainly useful for the tinydisplay software renderer. See Texture::set_quality_level().

traversePreparedTextures void GraphicsStateGuardian::traverse_prepared_textures(bool (*func)(TextureContext *tc, void *callback_arg), void *callback_arg); HAVE_PYTHON Description: Calls the indicated function on all currently-prepared textures, or until the callback function returns false.

getClassType static TypeHandle GraphicsStateGuardianBase::get_class_type(void); Undocumented function.

getDefaultGsg static GraphicsStateGuardianBase *GraphicsStateGuardianBase::get_default_gsg(void); Description: Returns a pointer to the "default" GSG. This is typically the first GSG created in an application; in a single-window application, it will be the only GSG. This GSG is used to determine default optimization choices for loaded geometry. The return value may be NULL if a GSG has not been created.

getEffectiveIncompleteRender virtual bool GraphicsStateGuardianBase::get_effective_incomplete_render(void) const = 0; Undocumented function.

getGsg static GraphicsStateGuardianBase *GraphicsStateGuardianBase::get_gsg(int n); Description: Returns the nth GSG in the universe. GSG's automatically add themselves and remove themselves from this list as they are created and destroyed.

getIncompleteRender virtual bool GraphicsStateGuardianBase::get_incomplete_render(void) const = 0; Undocumented function.

getMaxTextureDimension virtual int GraphicsStateGuardianBase::get_max_texture_dimension(void) const = 0; Undocumented function.

getMaxVerticesPerArray virtual int GraphicsStateGuardianBase::get_max_vertices_per_array(void) const = 0; Undocumented function.

getMaxVerticesPerPrimitive virtual int GraphicsStateGuardianBase::get_max_vertices_per_primitive(void) const = 0; Undocumented function.

getNumGsgs static int GraphicsStateGuardianBase::get_num_gsgs(void); Description: Returns the total number of GSG's in the universe.

getSupportedGeomRendering virtual int GraphicsStateGuardianBase::get_supported_geom_rendering(void) const = 0; Undocumented function.

getSupportsCompressedTextureFormat virtual bool GraphicsStateGuardianBase::get_supports_compressed_texture_format(int compression_mode) const = 0; Undocumented function.

getSupportsMultisample virtual bool GraphicsStateGuardianBase::get_supports_multisample(void) const = 0; Undocumented function.

getSupportsOcclusionQuery virtual bool GraphicsStateGuardianBase::get_supports_occlusion_query(void) const = 0; Undocumented function.

prefersTriangleStrips virtual bool GraphicsStateGuardianBase::prefers_triangle_strips(void) const = 0; Undocumented function.

setDefaultGsg static void GraphicsStateGuardianBase::set_default_gsg(GraphicsStateGuardianBase *default_gsg); Description: Specifies a particular GSG to use as the "default" GSG. See get_default_gsg().

getClassType static TypeHandle TypedWritableReferenceCount::get_class_type(void); Undocumented function.

getClassType static TypeHandle TypedWritable::get_class_type(void); Undocumented function.

getClassType static TypeHandle TypedObject::get_class_type(void); Undocumented function.

getType virtual TypeHandle TypedObject::get_type(void) const = 0; Derived classes should override this function to return get_class_type().

getTypeIndex int TypedObject::get_type_index(void) const; Description: Returns the internal index number associated with this object's TypeHandle, a unique number for each different type. This is equivalent to get_type().get_index().

isExactType bool TypedObject::is_exact_type(TypeHandle handle) const; Description: Returns true if the current object is the indicated type exactly.

isOfType bool TypedObject::is_of_type(TypeHandle handle) const; Description: Returns true if the current object is or derives from the indicated type.

getClassType static TypeHandle ReferenceCount::get_class_type(void); Undocumented function.

getRefCount int ReferenceCount::get_ref_count(void) const; Description: Returns the current reference count.

ref void ReferenceCount::ref(void) const; Description: Explicitly increments the reference count. User code should avoid using ref() and unref() directly, which can result in missed reference counts. Instead, let a PointerTo object manage the reference counting automatically. This function is const, even though it changes the object, because generally fiddling with an object's reference count isn't considered part of fiddling with the object. An object might be const in other ways, but we still need to accurately count the number of references to it.

testRefCountIntegrity bool ReferenceCount::test_ref_count_integrity(void) const; Description: Does some easy checks to make sure that the reference count isn't completely bogus. Returns true if ok, false otherwise.

testRefCountNonzero bool ReferenceCount::test_ref_count_nonzero(void) const; Description: Does some easy checks to make sure that the reference count isn't zero, or completely bogus. Returns true if ok, false otherwise.

unref bool ReferenceCount::unref(void) const; Description: Explicitly decrements the reference count. Note that the object will not be implicitly deleted by unref() simply because the reference count drops to zero. (Having a member function delete itself is problematic; plus, we don't have a virtual destructor anyway.) However, see the helper function unref_delete(). User code should avoid using ref() and unref() directly, which can result in missed reference counts. Instead, let a PointerTo object manage the reference counting automatically. This function is const, even though it changes the object, because generally fiddling with an object's reference count isn't considered part of fiddling with the object. An object might be const in other ways, but we still need to accurately count the number of references to it. The return value is true if the new reference count is nonzero, false if it is zero.