GLES3 Backend

Relevant source files

The GLES3 backend is Godot's OpenGL ES 3.0 rendering path. It lives in drivers/gles3/ and implements the same abstract rendering interfaces as the RenderingDevice-based backends (Vulkan, D3D12, Metal), but targets lower-end hardware, mobile platforms, and embedded environments. This page covers the rasterizers, storage subsystems, material and shader management, and the GLSL shader structure specific to GLES3.

For the RenderingDevice-based backends (Vulkan, D3D12, Metal), see 7.2. For the forward clustered and forward mobile pipelines that run on RenderingDevice, see 7.3. For the shader language parser and compiler shared by all backends, see 7.4.

Architecture Overview

The GLES3 backend is composed of two rasterizers and a set of storage singletons.

Top-level class diagram:

Sources: drivers/gles3/rasterizer_scene_gles3.h1-200 drivers/gles3/rasterizer_canvas_gles3.h1-100 drivers/gles3/storage/material_storage.h1-100

3D Scene Rendering: `RasterizerSceneGLES3`

RasterizerSceneGLES3 in drivers/gles3/rasterizer_scene_gles3.cpp implements RendererSceneRender. Its central responsibility is managing geometry instances, building render lists, and issuing OpenGL draw calls for 3D scenes.

Per-Frame Data: `RenderDataGLES3`

Every render call receives a RenderDataGLES3 struct (drivers/gles3/rasterizer_scene_gles3.h98-146) that carries:

Field	Type	Purpose
`render_buffers`	`Ref<RenderSceneBuffersGLES3>`	Render targets and intermediate textures
`cam_transform`	`Transform3D`	Camera world transform
`cam_projection`	`Projection`	Camera projection matrix
`view_count`	`uint32_t`	Number of views (1 for mono, 2 for XR)
`instances`	`PagedArray<RenderGeometryInstance>`	Visible geometry
`lights`	`PagedArray<RID>*`	Active lights
`environment`	`RID`	Current environment resource
`directional_light_count`	`uint32_t`	How many directional lights
`luminance_multiplier`	`float`	For physical light unit normalization

Render Lists

Geometry is sorted into three render lists, typed by RenderListType:

Constant	Value	Usage
`RENDER_LIST_OPAQUE`	0	Opaque geometry
`RENDER_LIST_ALPHA`	1	Transparent geometry
`RENDER_LIST_SECONDARY`	2	Shadows and other auxiliary passes

Passes are identified by PassMode:

PASS_MODE_COLOR / PASS_MODE_COLOR_TRANSPARENT
PASS_MODE_SHADOW
PASS_MODE_DEPTH
PASS_MODE_MATERIAL
PASS_MODE_MOTION_VECTORS

Geometry Instance Lifecycle

Each visible 3D object is represented as a GeometryInstanceGLES3, which caches resolved surface/material data as a linked list of GeometryInstanceSurface entries.

Geometry instance lifecycle:

Sources: drivers/gles3/rasterizer_scene_gles3.cpp56-511

`GeometryInstanceSurface` Pass Flags

When _geometry_instance_add_surface_with_material() creates a GeometryInstanceSurface, it computes flags that determine which render passes this surface participates in:

Flag	Meaning
`FLAG_PASS_OPAQUE`	Rendered in the opaque pass
`FLAG_PASS_ALPHA`	Rendered in the alpha-transparent pass
`FLAG_PASS_DEPTH`	Included in depth prepass
`FLAG_PASS_SHADOW`	Contributes to shadow maps
`FLAG_USES_SCREEN_TEXTURE`	Requires screen texture read
`FLAG_USES_DEPTH_TEXTURE`	Requires depth texture read
`FLAG_USES_SHARED_SHADOW_MATERIAL`	Shadow pass uses the default material instead of the object's material (optimization)
`FLAG_USES_STENCIL`	Uses stencil buffer operations

Sources: drivers/gles3/rasterizer_scene_gles3.cpp216-329

Sky Rendering

Sky resources are tracked via RasterizerSceneGLES3::Sky and managed with a dirty-list pattern identical to materials. The key steps are:

_setup_sky() — uploads directional light data to sky_globals.directional_light_buffer (UBO at SKY_DIRECTIONAL_LIGHT_UNIFORM_LOCATION).
_update_dirty_skys() — allocates GL_TEXTURE_CUBE_MAP radiance and raw radiance textures when a sky becomes dirty.
_draw_sky() — binds the sky shader version, sets uniforms (orientation, projection, time, fog parameters), and issues a full-screen draw.

The sky shader is managed through material_storage->shaders.sky_shader, a SkyShaderGLES3 instance with modes MODE_BACKGROUND and MODE_CUBEMAP.

Sources: drivers/gles3/rasterizer_scene_gles3.cpp513-891

2D Canvas Rendering: `RasterizerCanvasGLES3`

RasterizerCanvasGLES3 in drivers/gles3/rasterizer_canvas_gles3.cpp implements 2D rendering for all CanvasItem-based nodes (sprites, polygons, text, particles in 2D).

Main Entry Point

canvas_render_items(p_to_render_target, p_item_list, p_modulate,
                    p_light_list, p_directional_light_list,
                    p_canvas_transform, ...)

The function executes the following steps each frame:

Reset canvas state — clears residual 3D pipeline state via reset_canvas().
Fence synchronization — checks whether the current instance data buffer is still in use by the GPU. If so, either waits (desktop) or allocates a fresh buffer via _allocate_instance_data_buffer().
Directional light setup — fills state.light_uniforms[0..N] for directional lights, uploads to state.canvas_instance_data_buffers[...].light_ubo.
Point/spot light setup — fills remaining state.light_uniforms slots.
State UBO update — uploads StateBuffer (screen transform, canvas transform, modulate, time, SDF params).
Item iteration — calls _render_items() which batches draws and issues glDrawArraysInstanced or glDrawElements.

Instance Data Triple-Buffering

The canvas renderer uses up to 3 in-flight instance data buffers (canvas_instance_data_buffers[3]), each guarded by a GLsync fence. This avoids stalling the CPU waiting for the GPU to finish a previous frame's data.

Sources: drivers/gles3/rasterizer_canvas_gles3.cpp107-390

Canvas Light Uniforms

The LightUniform struct is packed into a UBO at LIGHT_UNIFORM_LOCATION. Each entry holds:

position[2] — canvas-space position
matrix[8] — 2x4 light transform
shadow_matrix[8] — 2x4 shadow transform
color[4], shadow_color[4]
flags — blend mode and shadow filter
atlas_rect[4] — texture atlas coordinates

Sources: drivers/gles3/rasterizer_canvas_gles3.cpp144-318

Material and Shader System: `GLES3::MaterialStorage`

GLES3::MaterialStorage in drivers/gles3/storage/material_storage.cpp manages the entire lifecycle from Godot's high-level shader source to compiled OpenGL programs and bound material data.

Material and shader data flow:

Sources: drivers/gles3/storage/material_storage.cpp1-200 drivers/gles3/storage/material_storage.h1-100

Shader Data Classes

Class	Shader Type	Backing GL shader
`SceneShaderData`	`shader_type spatial`	`SceneShaderGLES3`
`SkyShaderData`	`shader_type sky`	`SkyShaderGLES3`
`CanvasShaderData`	`shader_type canvas_item`	`CanvasShaderGLES3`

Each ShaderData subclass implements set_code(), which runs the source through ShaderCompiler to produce GLSL, then compiles it into an OpenGL shader version.

Material Data Classes

Each MaterialData subclass (e.g., SceneMaterialData) holds:

A reference to its parent ShaderData
The UBO containing material uniform values
A uniform_set_updated dirty flag
bind_uniforms() — uploads parameters to ubo:3
next_pass — pointer to the next material pass RID for multi-pass rendering

UBO Value Packing

_fill_std140_variant_ubo_value() at drivers/gles3/storage/material_storage.cpp49 converts Godot Variant values into std140-layout bytes for each ShaderLanguage::DataType. Arrays use write_array_std140<T>() which pads each element to a 4-float stride as required by std140.

GLSL Shader Structure

The GLES3 backend uses a custom .glsl format with two special header sections:

#[modes] — defines named compilation variants. Each mode becomes a separately linked GL program.
#[specializations] — defines boolean #define flags resolved at shader-bind time, creating shader variants without full recompilation.

Scene Shader (`drivers/gles3/shaders/scene.glsl`)

Modes:

Mode	Defines	Purpose
`mode_color`	(none)	Standard opaque color pass
`mode_color_instancing`	`USE_INSTANCING`	Instanced color pass
`mode_depth`	`MODE_RENDER_DEPTH`	Depth/shadow pass
`mode_depth_instancing`	`MODE_RENDER_DEPTH`, `USE_INSTANCING`	Instanced depth pass

Key specializations:

Specialization	Default	Purpose
`DISABLE_LIGHT_DIRECTIONAL`	false	Skip directional light computation
`DISABLE_LIGHT_OMNI`	false	Skip omni light computation
`DISABLE_LIGHT_SPOT`	false	Skip spot light computation
`USE_LIGHTMAP`	false	Sample baked lightmap
`USE_MULTIVIEW`	false	Stereo/XR rendering
`RENDER_SHADOWS`	false	Shadow depth encoding
`SHADOW_MODE_PCF_5`	false	5-tap PCF shadow filtering
`SHADOW_MODE_PCF_13`	false	13-tap PCF shadow filtering
`APPLY_TONEMAPPING`	true	Apply tonemapping in scene pass
`USE_ADDITIVE_LIGHTING`	false	Additive light accumulation pass
`ADDITIVE_OMNI`	false	Additive omni light sub-pass
`ADDITIVE_SPOT`	false	Additive spot light sub-pass
`BASE_PASS`	true	Base lighting pass (vs. additive)

Sources: drivers/gles3/shaders/scene.glsl1-42

Scene Shader UBO Layout

The scene vertex and fragment shaders use fixed binding points matching the SceneUniformLocation enum:

SceneData (at ubo:2) is a large struct that includes projection/view matrices, viewport size, ambient light color, fog parameters, z-near/far, shadow bias, and frame time.

Sources: drivers/gles3/shaders/scene.glsl179-237 drivers/gles3/rasterizer_scene_gles3.h64-96

Canvas Shader (`drivers/gles3/shaders/canvas.glsl`)

The canvas shader has a single mode (mode_default) and is specialized via flags at bind time:

Specialization	Purpose
`DISABLE_LIGHTING`	Skip all light computation (true by default)
`USE_RGBA_SHADOWS`	Use RGBA-encoded shadow depth (for mobile)
`USE_NINEPATCH`	Enable nine-patch rect rendering
`USE_PRIMITIVE`	Triangle/line primitive mode
`USE_ATTRIBUTES`	Per-vertex attribute arrays (polygon rendering)
`USE_INSTANCING`	Instanced 2D sprite rendering

Instance data is packed into vertex attributes attrib_A through attrib_H at locations 8–15, carrying world transform, color, UV rect, source rect, flags, and light indices.

Sources: drivers/gles3/shaders/canvas.glsl1-90

Sky Shader (`drivers/gles3/shaders/sky.glsl`)

Mode	Defines	Purpose
`mode_background`	(none)	Draw sky into screen framebuffer
`mode_cubemap`	`USE_CUBEMAP_PASS`	Render sky into cubemap face

Specializations include USE_MULTIVIEW, USE_INVERTED_Y, and APPLY_TONEMAPPING.

Sources: drivers/gles3/shaders/sky.glsl1-20

Storage Subsystems

Each storage class is a singleton in the GLES3 namespace and manages a specific resource type using RID_Owner allocators.

Class	File	Manages
`GLES3::MeshStorage`	`drivers/gles3/storage/mesh_storage.cpp`	Meshes, multimeshes, skeletons
`GLES3::TextureStorage`	`drivers/gles3/storage/texture_storage.cpp`	Textures, render targets, texture atlas
`GLES3::LightStorage`	`drivers/gles3/storage/light_storage.cpp`	Lights, shadow atlases, light instances
`GLES3::ParticlesStorage`	`drivers/gles3/storage/particles_storage.cpp`	GPU particles, particle trails
`GLES3::MaterialStorage`	`drivers/gles3/storage/material_storage.cpp`	Shaders, materials, global uniforms
`GLES3::Utilities`	`drivers/gles3/storage/utilities.cpp`	Texture memory tracking, base type queries
`GLES3::Config`	`drivers/gles3/storage/config.cpp`	Runtime GL capability flags and limits

`GLES3::Config`

Config is queried throughout the backend for hardware limits, e.g.:

max_renderable_lights — caps get_max_lights_total()
max_lights_per_object — caps GeometryInstanceGLES3::pair_light_instance()
max_texture_image_units — used when binding atlas and shadow textures in canvas_render_items()

Sources: drivers/gles3/rasterizer_scene_gles3.cpp78-84 drivers/gles3/rasterizer_canvas_gles3.cpp309-317

Post-Processing Effects

Effect helpers live in drivers/gles3/effects/:

File	Class	Purpose
`effects/copy_effects.cpp`	`CopyEffects`	Blit, copy, and downsample passes
`effects/cubemap_filter.cpp`	`CubemapFilter`	Specular convolution for radiance maps
`effects/feed_effects.cpp`	`FeedEffects`	Camera feed texture rendering
`effects/post_effects.cpp`	`PostEffects`	Tonemapping, glow, adjustments

These are invoked from RasterizerSceneGLES3 after the main geometry passes.

Sources: drivers/gles3/rasterizer_scene_gles3.cpp37-41

GL API vs. GLES API Paths

Several codepaths branch on RasterizerUtilGLES3::is_gles_over_gl() to accommodate differences between desktop OpenGL and GLES3:

Radiance texture allocation: desktop uses glTexImage2D + glGenerateMipmap; GLES uses glTexStorage2D.
Buffer mapping: desktop and mobile use glMapBufferRange with GL_MAP_UNSYNCHRONIZED_BIT; WebGL uses glBufferSubData (no explicit sync).

Sources: drivers/gles3/rasterizer_scene_gles3.cpp588-617 drivers/gles3/rasterizer_canvas_gles3.cpp293-302

GLES3 Backend

Relevant source files

Architecture Overview

The GLES3 backend is composed of two rasterizers and a set of storage singletons.

Top-level class diagram:

Sources: drivers/gles3/rasterizer_scene_gles3.h1-200 drivers/gles3/rasterizer_canvas_gles3.h1-100 drivers/gles3/storage/material_storage.h1-100

3D Scene Rendering: `RasterizerSceneGLES3`

Per-Frame Data: `RenderDataGLES3`

Every render call receives a RenderDataGLES3 struct (drivers/gles3/rasterizer_scene_gles3.h98-146) that carries:

Field	Type	Purpose
`render_buffers`	`Ref<RenderSceneBuffersGLES3>`	Render targets and intermediate textures
`cam_transform`	`Transform3D`	Camera world transform
`cam_projection`	`Projection`	Camera projection matrix
`view_count`	`uint32_t`	Number of views (1 for mono, 2 for XR)
`instances`	`PagedArray<RenderGeometryInstance>`	Visible geometry
`lights`	`PagedArray<RID>*`	Active lights
`environment`	`RID`	Current environment resource
`directional_light_count`	`uint32_t`	How many directional lights
`luminance_multiplier`	`float`	For physical light unit normalization

Render Lists

Geometry is sorted into three render lists, typed by RenderListType:

Constant	Value	Usage
`RENDER_LIST_OPAQUE`	0	Opaque geometry
`RENDER_LIST_ALPHA`	1	Transparent geometry
`RENDER_LIST_SECONDARY`	2	Shadows and other auxiliary passes

Passes are identified by PassMode:

PASS_MODE_COLOR / PASS_MODE_COLOR_TRANSPARENT
PASS_MODE_SHADOW
PASS_MODE_DEPTH
PASS_MODE_MATERIAL
PASS_MODE_MOTION_VECTORS

Geometry Instance Lifecycle

Each visible 3D object is represented as a GeometryInstanceGLES3, which caches resolved surface/material data as a linked list of GeometryInstanceSurface entries.

Geometry instance lifecycle:

Sources: drivers/gles3/rasterizer_scene_gles3.cpp56-511

`GeometryInstanceSurface` Pass Flags

When _geometry_instance_add_surface_with_material() creates a GeometryInstanceSurface, it computes flags that determine which render passes this surface participates in:

Flag	Meaning
`FLAG_PASS_OPAQUE`	Rendered in the opaque pass
`FLAG_PASS_ALPHA`	Rendered in the alpha-transparent pass
`FLAG_PASS_DEPTH`	Included in depth prepass
`FLAG_PASS_SHADOW`	Contributes to shadow maps
`FLAG_USES_SCREEN_TEXTURE`	Requires screen texture read
`FLAG_USES_DEPTH_TEXTURE`	Requires depth texture read
`FLAG_USES_SHARED_SHADOW_MATERIAL`	Shadow pass uses the default material instead of the object's material (optimization)
`FLAG_USES_STENCIL`	Uses stencil buffer operations

Sources: drivers/gles3/rasterizer_scene_gles3.cpp216-329

Sky Rendering

Sky resources are tracked via RasterizerSceneGLES3::Sky and managed with a dirty-list pattern identical to materials. The key steps are:

_setup_sky() — uploads directional light data to sky_globals.directional_light_buffer (UBO at SKY_DIRECTIONAL_LIGHT_UNIFORM_LOCATION).
_update_dirty_skys() — allocates GL_TEXTURE_CUBE_MAP radiance and raw radiance textures when a sky becomes dirty.
_draw_sky() — binds the sky shader version, sets uniforms (orientation, projection, time, fog parameters), and issues a full-screen draw.

The sky shader is managed through material_storage->shaders.sky_shader, a SkyShaderGLES3 instance with modes MODE_BACKGROUND and MODE_CUBEMAP.

Sources: drivers/gles3/rasterizer_scene_gles3.cpp513-891

2D Canvas Rendering: `RasterizerCanvasGLES3`

RasterizerCanvasGLES3 in drivers/gles3/rasterizer_canvas_gles3.cpp implements 2D rendering for all CanvasItem-based nodes (sprites, polygons, text, particles in 2D).

Main Entry Point

canvas_render_items(p_to_render_target, p_item_list, p_modulate,
                    p_light_list, p_directional_light_list,
                    p_canvas_transform, ...)

The function executes the following steps each frame:

Reset canvas state — clears residual 3D pipeline state via reset_canvas().
Fence synchronization — checks whether the current instance data buffer is still in use by the GPU. If so, either waits (desktop) or allocates a fresh buffer via _allocate_instance_data_buffer().
Directional light setup — fills state.light_uniforms[0..N] for directional lights, uploads to state.canvas_instance_data_buffers[...].light_ubo.
Point/spot light setup — fills remaining state.light_uniforms slots.
State UBO update — uploads StateBuffer (screen transform, canvas transform, modulate, time, SDF params).
Item iteration — calls _render_items() which batches draws and issues glDrawArraysInstanced or glDrawElements.

Instance Data Triple-Buffering

Sources: drivers/gles3/rasterizer_canvas_gles3.cpp107-390

Canvas Light Uniforms

The LightUniform struct is packed into a UBO at LIGHT_UNIFORM_LOCATION. Each entry holds:

position[2] — canvas-space position
matrix[8] — 2x4 light transform
shadow_matrix[8] — 2x4 shadow transform
color[4], shadow_color[4]
flags — blend mode and shadow filter
atlas_rect[4] — texture atlas coordinates

Sources: drivers/gles3/rasterizer_canvas_gles3.cpp144-318

Material and Shader System: `GLES3::MaterialStorage`

GLES3::MaterialStorage in drivers/gles3/storage/material_storage.cpp manages the entire lifecycle from Godot's high-level shader source to compiled OpenGL programs and bound material data.

Material and shader data flow:

Sources: drivers/gles3/storage/material_storage.cpp1-200 drivers/gles3/storage/material_storage.h1-100

Shader Data Classes

Class	Shader Type	Backing GL shader
`SceneShaderData`	`shader_type spatial`	`SceneShaderGLES3`
`SkyShaderData`	`shader_type sky`	`SkyShaderGLES3`
`CanvasShaderData`	`shader_type canvas_item`	`CanvasShaderGLES3`

Each ShaderData subclass implements set_code(), which runs the source through ShaderCompiler to produce GLSL, then compiles it into an OpenGL shader version.

Material Data Classes

Each MaterialData subclass (e.g., SceneMaterialData) holds:

A reference to its parent ShaderData
The UBO containing material uniform values
A uniform_set_updated dirty flag
bind_uniforms() — uploads parameters to ubo:3
next_pass — pointer to the next material pass RID for multi-pass rendering

UBO Value Packing

GLSL Shader Structure

The GLES3 backend uses a custom .glsl format with two special header sections:

#[modes] — defines named compilation variants. Each mode becomes a separately linked GL program.
#[specializations] — defines boolean #define flags resolved at shader-bind time, creating shader variants without full recompilation.

Scene Shader (`drivers/gles3/shaders/scene.glsl`)

Modes:

Mode	Defines	Purpose
`mode_color`	(none)	Standard opaque color pass
`mode_color_instancing`	`USE_INSTANCING`	Instanced color pass
`mode_depth`	`MODE_RENDER_DEPTH`	Depth/shadow pass
`mode_depth_instancing`	`MODE_RENDER_DEPTH`, `USE_INSTANCING`	Instanced depth pass

Key specializations:

Specialization	Default	Purpose
`DISABLE_LIGHT_DIRECTIONAL`	false	Skip directional light computation
`DISABLE_LIGHT_OMNI`	false	Skip omni light computation
`DISABLE_LIGHT_SPOT`	false	Skip spot light computation
`USE_LIGHTMAP`	false	Sample baked lightmap
`USE_MULTIVIEW`	false	Stereo/XR rendering
`RENDER_SHADOWS`	false	Shadow depth encoding
`SHADOW_MODE_PCF_5`	false	5-tap PCF shadow filtering
`SHADOW_MODE_PCF_13`	false	13-tap PCF shadow filtering
`APPLY_TONEMAPPING`	true	Apply tonemapping in scene pass
`USE_ADDITIVE_LIGHTING`	false	Additive light accumulation pass
`ADDITIVE_OMNI`	false	Additive omni light sub-pass
`ADDITIVE_SPOT`	false	Additive spot light sub-pass
`BASE_PASS`	true	Base lighting pass (vs. additive)

Sources: drivers/gles3/shaders/scene.glsl1-42

Scene Shader UBO Layout

The scene vertex and fragment shaders use fixed binding points matching the SceneUniformLocation enum:

SceneData (at ubo:2) is a large struct that includes projection/view matrices, viewport size, ambient light color, fog parameters, z-near/far, shadow bias, and frame time.

Sources: drivers/gles3/shaders/scene.glsl179-237 drivers/gles3/rasterizer_scene_gles3.h64-96

Canvas Shader (`drivers/gles3/shaders/canvas.glsl`)

The canvas shader has a single mode (mode_default) and is specialized via flags at bind time:

Specialization	Purpose
`DISABLE_LIGHTING`	Skip all light computation (true by default)
`USE_RGBA_SHADOWS`	Use RGBA-encoded shadow depth (for mobile)
`USE_NINEPATCH`	Enable nine-patch rect rendering
`USE_PRIMITIVE`	Triangle/line primitive mode
`USE_ATTRIBUTES`	Per-vertex attribute arrays (polygon rendering)
`USE_INSTANCING`	Instanced 2D sprite rendering

Instance data is packed into vertex attributes attrib_A through attrib_H at locations 8–15, carrying world transform, color, UV rect, source rect, flags, and light indices.

Sources: drivers/gles3/shaders/canvas.glsl1-90

Sky Shader (`drivers/gles3/shaders/sky.glsl`)

Mode	Defines	Purpose
`mode_background`	(none)	Draw sky into screen framebuffer
`mode_cubemap`	`USE_CUBEMAP_PASS`	Render sky into cubemap face

Specializations include USE_MULTIVIEW, USE_INVERTED_Y, and APPLY_TONEMAPPING.

Sources: drivers/gles3/shaders/sky.glsl1-20

Storage Subsystems

Each storage class is a singleton in the GLES3 namespace and manages a specific resource type using RID_Owner allocators.

Class	File	Manages
`GLES3::MeshStorage`	`drivers/gles3/storage/mesh_storage.cpp`	Meshes, multimeshes, skeletons
`GLES3::TextureStorage`	`drivers/gles3/storage/texture_storage.cpp`	Textures, render targets, texture atlas
`GLES3::LightStorage`	`drivers/gles3/storage/light_storage.cpp`	Lights, shadow atlases, light instances
`GLES3::ParticlesStorage`	`drivers/gles3/storage/particles_storage.cpp`	GPU particles, particle trails
`GLES3::MaterialStorage`	`drivers/gles3/storage/material_storage.cpp`	Shaders, materials, global uniforms
`GLES3::Utilities`	`drivers/gles3/storage/utilities.cpp`	Texture memory tracking, base type queries
`GLES3::Config`	`drivers/gles3/storage/config.cpp`	Runtime GL capability flags and limits

`GLES3::Config`

Config is queried throughout the backend for hardware limits, e.g.:

max_renderable_lights — caps get_max_lights_total()
max_lights_per_object — caps GeometryInstanceGLES3::pair_light_instance()
max_texture_image_units — used when binding atlas and shadow textures in canvas_render_items()

Sources: drivers/gles3/rasterizer_scene_gles3.cpp78-84 drivers/gles3/rasterizer_canvas_gles3.cpp309-317

Post-Processing Effects

Effect helpers live in drivers/gles3/effects/:

File	Class	Purpose
`effects/copy_effects.cpp`	`CopyEffects`	Blit, copy, and downsample passes
`effects/cubemap_filter.cpp`	`CubemapFilter`	Specular convolution for radiance maps
`effects/feed_effects.cpp`	`FeedEffects`	Camera feed texture rendering
`effects/post_effects.cpp`	`PostEffects`	Tonemapping, glow, adjustments

These are invoked from RasterizerSceneGLES3 after the main geometry passes.

Sources: drivers/gles3/rasterizer_scene_gles3.cpp37-41

GL API vs. GLES API Paths

Several codepaths branch on RasterizerUtilGLES3::is_gles_over_gl() to accommodate differences between desktop OpenGL and GLES3:

Radiance texture allocation: desktop uses glTexImage2D + glGenerateMipmap; GLES uses glTexStorage2D.
Buffer mapping: desktop and mobile use glMapBufferRange with GL_MAP_UNSYNCHRONIZED_BIT; WebGL uses glBufferSubData (no explicit sync).

Sources: drivers/gles3/rasterizer_scene_gles3.cpp588-617 drivers/gles3/rasterizer_canvas_gles3.cpp293-302

GLES3 Backend

Architecture Overview

3D Scene Rendering: RasterizerSceneGLES3

Per-Frame Data: RenderDataGLES3

Render Lists

Geometry Instance Lifecycle

GeometryInstanceSurface Pass Flags

Sky Rendering

2D Canvas Rendering: RasterizerCanvasGLES3

Main Entry Point

Instance Data Triple-Buffering

Canvas Light Uniforms

Material and Shader System: GLES3::MaterialStorage

Shader Data Classes

Material Data Classes

UBO Value Packing

GLSL Shader Structure

Scene Shader (drivers/gles3/shaders/scene.glsl)

Scene Shader UBO Layout

Canvas Shader (drivers/gles3/shaders/canvas.glsl)

Sky Shader (drivers/gles3/shaders/sky.glsl)

Storage Subsystems

GLES3::Config

Post-Processing Effects

GL API vs. GLES API Paths

On this page

GLES3 Backend

Architecture Overview

3D Scene Rendering: RasterizerSceneGLES3

Per-Frame Data: RenderDataGLES3

Render Lists

Geometry Instance Lifecycle

GeometryInstanceSurface Pass Flags

Sky Rendering

2D Canvas Rendering: RasterizerCanvasGLES3

Main Entry Point

Instance Data Triple-Buffering

Canvas Light Uniforms

Material and Shader System: GLES3::MaterialStorage

Shader Data Classes

Material Data Classes

UBO Value Packing

GLSL Shader Structure

Scene Shader (drivers/gles3/shaders/scene.glsl)

Scene Shader UBO Layout

Canvas Shader (drivers/gles3/shaders/canvas.glsl)

Sky Shader (drivers/gles3/shaders/sky.glsl)

Storage Subsystems

GLES3::Config

Post-Processing Effects

GL API vs. GLES API Paths

On this page

3D Scene Rendering: `RasterizerSceneGLES3`

Per-Frame Data: `RenderDataGLES3`

`GeometryInstanceSurface` Pass Flags

2D Canvas Rendering: `RasterizerCanvasGLES3`

Material and Shader System: `GLES3::MaterialStorage`

Scene Shader (`drivers/gles3/shaders/scene.glsl`)

Canvas Shader (`drivers/gles3/shaders/canvas.glsl`)

Sky Shader (`drivers/gles3/shaders/sky.glsl`)

`GLES3::Config`

3D Scene Rendering: `RasterizerSceneGLES3`

Per-Frame Data: `RenderDataGLES3`

`GeometryInstanceSurface` Pass Flags

2D Canvas Rendering: `RasterizerCanvasGLES3`

Material and Shader System: `GLES3::MaterialStorage`

Scene Shader (`drivers/gles3/shaders/scene.glsl`)

Canvas Shader (`drivers/gles3/shaders/canvas.glsl`)

Sky Shader (`drivers/gles3/shaders/sky.glsl`)

`GLES3::Config`