Add multiview to the opengl3 driver

14 files changed, 265 insertions, 56 deletions

diff --git a/drivers/gles3/rasterizer_gles3.cpp b/drivers/gles3/rasterizer_gles3.cpp
index 0836a21254..ea97dff522 100644
--- a/drivers/gles3/rasterizer_gles3.cpp
+++ b/drivers/gles3/rasterizer_gles3.cpp
@@ -274,15 +274,32 @@ RasterizerGLES3::~RasterizerGLES3() {
 void RasterizerGLES3::prepare_for_blitting_render_targets() {
 }
 
-void RasterizerGLES3::_blit_render_target_to_screen(RID p_render_target, DisplayServer::WindowID p_screen, const Rect2 &p_screen_rect) {
+void RasterizerGLES3::_blit_render_target_to_screen(RID p_render_target, DisplayServer::WindowID p_screen, const Rect2 &p_screen_rect, uint32_t p_layer) {
 	GLES3::RenderTarget *rt = GLES3::TextureStorage::get_singleton()->get_render_target(p_render_target);
+
 	ERR_FAIL_COND(!rt);
 
-	glBindFramebuffer(GL_READ_FRAMEBUFFER, rt->fbo);
+	GLuint read_fbo = 0;
+	if (rt->view_count > 1) {
+		glGenFramebuffers(1, &read_fbo);
+		glBindFramebuffer(GL_READ_FRAMEBUFFER, read_fbo);
+		glFramebufferTextureLayer(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, rt->color, 0, p_layer);
+	} else {
+		glBindFramebuffer(GL_READ_FRAMEBUFFER, rt->fbo);
+	}
+
 	glReadBuffer(GL_COLOR_ATTACHMENT0);
 	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, GLES3::TextureStorage::system_fbo);
 	// Flip content upside down to correct for coordinates.
-	glBlitFramebuffer(0, 0, rt->size.x, rt->size.y, 0, p_screen_rect.size.y, p_screen_rect.size.x, 0, GL_COLOR_BUFFER_BIT, GL_NEAREST);
+	Vector2i screen_rect_end = p_screen_rect.get_end();
+	glBlitFramebuffer(0, 0, rt->size.x, rt->size.y,
+			p_screen_rect.position.x, screen_rect_end.y, screen_rect_end.x, p_screen_rect.position.y,
+			GL_COLOR_BUFFER_BIT, GL_NEAREST);
+
+	if (read_fbo != 0) {
+		glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
+		glDeleteFramebuffers(1, &read_fbo);
+	}
 }
 
 // is this p_screen useless in a multi window environment?
@@ -293,7 +310,7 @@ void RasterizerGLES3::blit_render_targets_to_screen(DisplayServer::WindowID p_sc
 		RID rid_rt = blit.render_target;
 
 		Rect2 dst_rect = blit.dst_rect;
-		_blit_render_target_to_screen(rid_rt, p_screen, dst_rect);
+		_blit_render_target_to_screen(rid_rt, p_screen, dst_rect, blit.multi_view.use_layer ? blit.multi_view.layer : 0);
 	}
 }
 
diff --git a/drivers/gles3/rasterizer_gles3.h b/drivers/gles3/rasterizer_gles3.h
index 431515fd0d..d7d26685b4 100644
--- a/drivers/gles3/rasterizer_gles3.h
+++ b/drivers/gles3/rasterizer_gles3.h
@@ -68,7 +68,7 @@ protected:
 	RasterizerCanvasGLES3 *canvas = nullptr;
 	RasterizerSceneGLES3 *scene = nullptr;
 
-	void _blit_render_target_to_screen(RID p_render_target, DisplayServer::WindowID p_screen, const Rect2 &p_screen_rect);
+	void _blit_render_target_to_screen(RID p_render_target, DisplayServer::WindowID p_screen, const Rect2 &p_screen_rect, uint32_t p_layer);
 
 public:
 	RendererUtilities *get_utilities() { return utilities; }
diff --git a/drivers/gles3/rasterizer_scene_gles3.cpp b/drivers/gles3/rasterizer_scene_gles3.cpp
index d6486801e7..da713a5259 100644
--- a/drivers/gles3/rasterizer_scene_gles3.cpp
+++ b/drivers/gles3/rasterizer_scene_gles3.cpp
@@ -1273,6 +1273,19 @@ void RasterizerSceneGLES3::_setup_environment(const RenderDataGLES3 *p_render_da
 	GLES3::MaterialStorage::store_transform(p_render_data->cam_transform, scene_state.ubo.inv_view_matrix);
 	GLES3::MaterialStorage::store_transform(p_render_data->inv_cam_transform, scene_state.ubo.view_matrix);
 
+	if (p_render_data->view_count > 1) {
+		for (uint32_t v = 0; v < p_render_data->view_count; v++) {
+			projection = correction * p_render_data->view_projection[v];
+			GLES3::MaterialStorage::store_camera(projection, scene_state.multiview_ubo.projection_matrix_view[v]);
+			GLES3::MaterialStorage::store_camera(projection.inverse(), scene_state.multiview_ubo.inv_projection_matrix_view[v]);
+
+			scene_state.multiview_ubo.eye_offset[v][0] = p_render_data->view_eye_offset[v].x;
+			scene_state.multiview_ubo.eye_offset[v][1] = p_render_data->view_eye_offset[v].y;
+			scene_state.multiview_ubo.eye_offset[v][2] = p_render_data->view_eye_offset[v].z;
+			scene_state.multiview_ubo.eye_offset[v][3] = 0.0;
+		}
+	}
+
 	scene_state.ubo.directional_light_count = p_render_data->directional_light_count;
 
 	scene_state.ubo.z_far = p_render_data->z_far;
@@ -1374,6 +1387,15 @@ void RasterizerSceneGLES3::_setup_environment(const RenderDataGLES3 *p_render_da
 	glBindBufferBase(GL_UNIFORM_BUFFER, SCENE_DATA_UNIFORM_LOCATION, scene_state.ubo_buffer);
 	glBufferData(GL_UNIFORM_BUFFER, sizeof(SceneState::UBO), &scene_state.ubo, GL_STREAM_DRAW);
 	glBindBuffer(GL_UNIFORM_BUFFER, 0);
+
+	if (p_render_data->view_count > 1) {
+		if (scene_state.multiview_buffer == 0) {
+			glGenBuffers(1, &scene_state.multiview_buffer);
+		}
+		glBindBufferBase(GL_UNIFORM_BUFFER, SCENE_MULTIVIEW_UNIFORM_LOCATION, scene_state.multiview_buffer);
+		glBufferData(GL_UNIFORM_BUFFER, sizeof(SceneState::MultiviewUBO), &scene_state.multiview_ubo, GL_STREAM_DRAW);
+		glBindBuffer(GL_UNIFORM_BUFFER, 0);
+	}
 }
 
 // Puts lights into Uniform Buffers. Needs to be called before _fill_list as this caches the index of each light in the Uniform Buffer
@@ -1916,8 +1938,14 @@ void RasterizerSceneGLES3::_render_list_template(RenderListParameters *p_params,
 	GLES3::SceneShaderData *prev_shader = nullptr;
 	GeometryInstanceGLES3 *prev_inst = nullptr;
 	SceneShaderGLES3::ShaderVariant prev_variant = SceneShaderGLES3::ShaderVariant::MODE_COLOR;
+	SceneShaderGLES3::ShaderVariant shader_variant = SceneShaderGLES3::MODE_COLOR; // Assigned to silence wrong -Wmaybe-initialized
 
-	SceneShaderGLES3::ShaderVariant shader_variant = SceneShaderGLES3::MODE_COLOR; // Assigned to silence wrong -Wmaybe-initialized.
+	// @todo Get this from p_params->spec_constant_base_flags instead of hardcoding it.
+	uint32_t base_spec_constants = 0;
+
+	if (p_render_data->view_count > 1) {
+		base_spec_constants |= 1 << SPEC_CONSTANT_USE_MULTIVIEW;
+	}
 
 	switch (p_pass_mode) {
 		case PASS_MODE_COLOR:
@@ -1957,8 +1985,6 @@ void RasterizerSceneGLES3::_render_list_template(RenderListParameters *p_params,
 			continue;
 		}
 
-		//uint32_t base_spec_constants = p_params->spec_constant_base_flags;
-
 		GLES3::SceneShaderData *shader;
 		GLES3::SceneMaterialData *material_data;
 		void *mesh_surface;
@@ -2128,7 +2154,7 @@ void RasterizerSceneGLES3::_render_list_template(RenderListParameters *p_params,
 		}
 
 		if (prev_shader != shader || prev_variant != instance_variant) {
-			material_storage->shaders.scene_shader.version_bind_shader(shader->version, instance_variant);
+			material_storage->shaders.scene_shader.version_bind_shader(shader->version, instance_variant, base_spec_constants);
 			float opaque_prepass_threshold = 0.0;
 			if constexpr (p_pass_mode == PASS_MODE_DEPTH) {
 				opaque_prepass_threshold = 0.99;
@@ -2136,7 +2162,7 @@ void RasterizerSceneGLES3::_render_list_template(RenderListParameters *p_params,
 				opaque_prepass_threshold = 0.1;
 			}
 
-			material_storage->shaders.scene_shader.version_set_uniform(SceneShaderGLES3::OPAQUE_PREPASS_THRESHOLD, opaque_prepass_threshold, shader->version, instance_variant);
+			material_storage->shaders.scene_shader.version_set_uniform(SceneShaderGLES3::OPAQUE_PREPASS_THRESHOLD, opaque_prepass_threshold, shader->version, instance_variant, base_spec_constants);
 
 			prev_shader = shader;
 			prev_variant = instance_variant;
@@ -2144,21 +2170,21 @@ void RasterizerSceneGLES3::_render_list_template(RenderListParameters *p_params,
 
 		if (prev_inst != inst || prev_shader != shader || prev_variant != instance_variant) {
 			// Rebind the light indices.
-			material_storage->shaders.scene_shader.version_set_uniform(SceneShaderGLES3::OMNI_LIGHT_COUNT, inst->omni_light_count, shader->version, instance_variant);
-			material_storage->shaders.scene_shader.version_set_uniform(SceneShaderGLES3::SPOT_LIGHT_COUNT, inst->spot_light_count, shader->version, instance_variant);
+			material_storage->shaders.scene_shader.version_set_uniform(SceneShaderGLES3::OMNI_LIGHT_COUNT, inst->omni_light_count, shader->version, instance_variant, base_spec_constants);
+			material_storage->shaders.scene_shader.version_set_uniform(SceneShaderGLES3::SPOT_LIGHT_COUNT, inst->spot_light_count, shader->version, instance_variant, base_spec_constants);
 
 			if (inst->omni_light_count) {
-				glUniform1uiv(material_storage->shaders.scene_shader.version_get_uniform(SceneShaderGLES3::OMNI_LIGHT_INDICES, shader->version, instance_variant), inst->omni_light_count, inst->omni_light_gl_cache.ptr());
+				glUniform1uiv(material_storage->shaders.scene_shader.version_get_uniform(SceneShaderGLES3::OMNI_LIGHT_INDICES, shader->version, instance_variant, base_spec_constants), inst->omni_light_count, inst->omni_light_gl_cache.ptr());
 			}
 
 			if (inst->spot_light_count) {
-				glUniform1uiv(material_storage->shaders.scene_shader.version_get_uniform(SceneShaderGLES3::SPOT_LIGHT_INDICES, shader->version, instance_variant), inst->spot_light_count, inst->spot_light_gl_cache.ptr());
+				glUniform1uiv(material_storage->shaders.scene_shader.version_get_uniform(SceneShaderGLES3::SPOT_LIGHT_INDICES, shader->version, instance_variant, base_spec_constants), inst->spot_light_count, inst->spot_light_gl_cache.ptr());
 			}
 
 			prev_inst = inst;
 		}
 
-		material_storage->shaders.scene_shader.version_set_uniform(SceneShaderGLES3::WORLD_TRANSFORM, world_transform, shader->version, instance_variant);
+		material_storage->shaders.scene_shader.version_set_uniform(SceneShaderGLES3::WORLD_TRANSFORM, world_transform, shader->version, instance_variant, base_spec_constants);
 		if (inst->instance_count > 0) {
 			// Using MultiMesh.
 			// Bind instance buffers.
diff --git a/drivers/gles3/rasterizer_scene_gles3.h b/drivers/gles3/rasterizer_scene_gles3.h
index 3895620228..3a759425e2 100644
--- a/drivers/gles3/rasterizer_scene_gles3.h
+++ b/drivers/gles3/rasterizer_scene_gles3.h
@@ -74,6 +74,7 @@ enum SceneUniformLocation {
 	SCENE_OMNILIGHT_UNIFORM_LOCATION,
 	SCENE_SPOTLIGHT_UNIFORM_LOCATION,
 	SCENE_DIRECTIONAL_LIGHT_UNIFORM_LOCATION,
+	SCENE_MULTIVIEW_UNIFORM_LOCATION,
 };
 
 enum SkyUniformLocation {
@@ -90,6 +91,8 @@ enum {
 	SPEC_CONSTANT_DISABLE_OMNI_LIGHTS = 2,
 	SPEC_CONSTANT_DISABLE_SPOT_LIGHTS = 3,
 	SPEC_CONSTANT_DISABLE_FOG = 4,
+	SPEC_CONSTANT_USE_RADIANCE_MAP = 5,
+	SPEC_CONSTANT_USE_MULTIVIEW = 6,
 };
 
 struct RenderDataGLES3 {
@@ -343,6 +346,13 @@ private:
 		};
 		static_assert(sizeof(UBO) % 16 == 0, "Scene UBO size must be a multiple of 16 bytes");
 
+		struct MultiviewUBO {
+			float projection_matrix_view[RendererSceneRender::MAX_RENDER_VIEWS][16];
+			float inv_projection_matrix_view[RendererSceneRender::MAX_RENDER_VIEWS][16];
+			float eye_offset[RendererSceneRender::MAX_RENDER_VIEWS][4];
+		};
+		static_assert(sizeof(MultiviewUBO) % 16 == 0, "Multiview UBO size must be a multiple of 16 bytes");
+
 		struct TonemapUBO {
 			float exposure = 1.0;
 			float white = 1.0;
@@ -353,6 +363,8 @@ private:
 
 		UBO ubo;
 		GLuint ubo_buffer = 0;
+		MultiviewUBO multiview_ubo;
+		GLuint multiview_buffer = 0;
 		GLuint tonemap_buffer = 0;
 
 		bool used_depth_prepass = false;
diff --git a/drivers/gles3/shader_gles3.cpp b/drivers/gles3/shader_gles3.cpp
index 033f10dbc5..2ff7f72180 100644
--- a/drivers/gles3/shader_gles3.cpp
+++ b/drivers/gles3/shader_gles3.cpp
@@ -142,7 +142,7 @@ RID ShaderGLES3::version_create() {
 	return version_owner.make_rid(version);
 }
 
-void ShaderGLES3::_build_variant_code(StringBuilder &builder, uint32_t p_variant, const Version *p_version, const StageTemplate &p_template, uint64_t p_specialization) {
+void ShaderGLES3::_build_variant_code(StringBuilder &builder, uint32_t p_variant, const Version *p_version, StageType p_stage_type, uint64_t p_specialization) {
 #ifdef GLES_OVER_GL
 	builder.append("#version 330\n");
 	builder.append("#define USE_GLES_OVER_GL\n");
@@ -171,6 +171,24 @@ void ShaderGLES3::_build_variant_code(StringBuilder &builder, uint32_t p_variant
 	}
 	builder.append("\n"); //make sure defines begin at newline
 
+	// Insert multiview extension loading, because it needs to appear before
+	// any non-preprocessor code (like the "precision highp..." lines below).
+	builder.append("#ifdef USE_MULTIVIEW\n");
+	builder.append("#if defined(GL_OVR_multiview2)\n");
+	builder.append("#extension GL_OVR_multiview2 : require\n");
+	builder.append("#elif defined(GL_OVR_multiview)\n");
+	builder.append("#extension GL_OVR_multiview : require\n");
+	builder.append("#endif\n");
+	if (p_stage_type == StageType::STAGE_TYPE_VERTEX) {
+		builder.append("layout(num_views=2) in;\n");
+	}
+	builder.append("#define ViewIndex gl_ViewID_OVR\n");
+	builder.append("#define MAX_VIEWS 2\n");
+	builder.append("#else\n");
+	builder.append("#define ViewIndex 0\n");
+	builder.append("#define MAX_VIEWS 1\n");
+	builder.append("#endif\n");
+
 	// Default to highp precision unless specified otherwise.
 	builder.append("precision highp float;\n");
 	builder.append("precision highp int;\n");
@@ -180,8 +198,9 @@ void ShaderGLES3::_build_variant_code(StringBuilder &builder, uint32_t p_variant
 	builder.append("precision highp sampler2DArray;\n");
 #endif
 
-	for (uint32_t i = 0; i < p_template.chunks.size(); i++) {
-		const StageTemplate::Chunk &chunk = p_template.chunks[i];
+	const StageTemplate &stage_template = stage_templates[p_stage_type];
+	for (uint32_t i = 0; i < stage_template.chunks.size(); i++) {
+		const StageTemplate::Chunk &chunk = stage_template.chunks[i];
 		switch (chunk.type) {
 			case StageTemplate::Chunk::TYPE_MATERIAL_UNIFORMS: {
 				builder.append(p_version->uniforms.get_data()); //uniforms (same for vertex and fragment)
@@ -224,7 +243,7 @@ void ShaderGLES3::_compile_specialization(Version::Specialization &spec, uint32_
 	//vertex stage
 	{
 		StringBuilder builder;
-		_build_variant_code(builder, p_variant, p_version, stage_templates[STAGE_TYPE_VERTEX], p_specialization);
+		_build_variant_code(builder, p_variant, p_version, STAGE_TYPE_VERTEX, p_specialization);
 
 		spec.vert_id = glCreateShader(GL_VERTEX_SHADER);
 		String builder_string = builder.as_string();
@@ -272,7 +291,7 @@ void ShaderGLES3::_compile_specialization(Version::Specialization &spec, uint32_
 	//fragment stage
 	{
 		StringBuilder builder;
-		_build_variant_code(builder, p_variant, p_version, stage_templates[STAGE_TYPE_FRAGMENT], p_specialization);
+		_build_variant_code(builder, p_variant, p_version, STAGE_TYPE_FRAGMENT, p_specialization);
 
 		spec.frag_id = glCreateShader(GL_FRAGMENT_SHADER);
 		String builder_string = builder.as_string();
@@ -413,7 +432,7 @@ RS::ShaderNativeSourceCode ShaderGLES3::version_get_native_source_code(RID p_ver
 
 		{
 			StringBuilder builder;
-			_build_variant_code(builder, i, version, stage_templates[STAGE_TYPE_VERTEX], specialization_default_mask);
+			_build_variant_code(builder, i, version, STAGE_TYPE_VERTEX, specialization_default_mask);
 
 			RS::ShaderNativeSourceCode::Version::Stage stage;
 			stage.name = "vertex";
@@ -425,7 +444,7 @@ RS::ShaderNativeSourceCode ShaderGLES3::version_get_native_source_code(RID p_ver
 		//fragment stage
 		{
 			StringBuilder builder;
-			_build_variant_code(builder, i, version, stage_templates[STAGE_TYPE_FRAGMENT], specialization_default_mask);
+			_build_variant_code(builder, i, version, STAGE_TYPE_FRAGMENT, specialization_default_mask);
 
 			RS::ShaderNativeSourceCode::Version::Stage stage;
 			stage.name = "fragment";
diff --git a/drivers/gles3/shader_gles3.h b/drivers/gles3/shader_gles3.h
index 2b72549b5b..760b5e5ddb 100644
--- a/drivers/gles3/shader_gles3.h
+++ b/drivers/gles3/shader_gles3.h
@@ -153,7 +153,7 @@ private:
 
 	StageTemplate stage_templates[STAGE_TYPE_MAX];
 
-	void _build_variant_code(StringBuilder &p_builder, uint32_t p_variant, const Version *p_version, const StageTemplate &p_template, uint64_t p_specialization);
+	void _build_variant_code(StringBuilder &p_builder, uint32_t p_variant, const Version *p_version, StageType p_stage_type, uint64_t p_specialization);
 
 	void _add_stage(const char *p_code, StageType p_stage_type);
 
diff --git a/drivers/gles3/shaders/scene.glsl b/drivers/gles3/shaders/scene.glsl
index efd6036ba9..2bd93796bd 100644
--- a/drivers/gles3/shaders/scene.glsl
+++ b/drivers/gles3/shaders/scene.glsl
@@ -16,6 +16,7 @@ DISABLE_LIGHT_OMNI = false
 DISABLE_LIGHT_SPOT = false
 DISABLE_FOG = false
 USE_RADIANCE_MAP = true
+USE_MULTIVIEW = false
 
 
 #[vertex]
@@ -153,6 +154,15 @@ layout(std140) uniform SceneData { // ubo:2
 }
 scene_data;
 
+#ifdef USE_MULTIVIEW
+layout(std140) uniform MultiviewData { // ubo:8
+	highp mat4 projection_matrix_view[MAX_VIEWS];
+	highp mat4 inv_projection_matrix_view[MAX_VIEWS];
+	highp vec4 eye_offset[MAX_VIEWS];
+}
+multiview_data;
+#endif
+
 uniform highp mat4 world_transform;
 
 #ifdef USE_LIGHTMAP
@@ -250,8 +260,14 @@ void main() {
 #if defined(OVERRIDE_POSITION)
 	highp vec4 position;
 #endif
-	highp mat4 projection_matrix = scene_data.projection_matrix;
-	highp mat4 inv_projection_matrix = scene_data.inv_projection_matrix;
+
+#ifdef USE_MULTIVIEW
+	mat4 projection_matrix = multiview_data.projection_matrix_view[ViewIndex];
+	mat4 inv_projection_matrix = multiview_data.inv_projection_matrix_view[ViewIndex];
+#else
+	mat4 projection_matrix = scene_data.projection_matrix;
+	mat4 inv_projection_matrix = scene_data.inv_projection_matrix;
+#endif //USE_MULTIVIEW
 
 #ifdef USE_INSTANCING
 	vec4 instance_custom = vec4(unpackHalf2x16(instance_color_custom_data.z), unpackHalf2x16(instance_color_custom_data.w));
@@ -339,7 +355,6 @@ void main() {
 /* clang-format off */
 #[fragment]
 
-
 // Default to SPECULAR_SCHLICK_GGX.
 #if !defined(SPECULAR_DISABLED) && !defined(SPECULAR_SCHLICK_GGX) && !defined(SPECULAR_TOON)
 #define SPECULAR_SCHLICK_GGX
@@ -463,6 +478,15 @@ layout(std140) uniform SceneData { // ubo:2
 }
 scene_data;
 
+#ifdef USE_MULTIVIEW
+layout(std140) uniform MultiviewData { // ubo:8
+	highp mat4 projection_matrix_view[MAX_VIEWS];
+	highp mat4 inv_projection_matrix_view[MAX_VIEWS];
+	highp vec4 eye_offset[MAX_VIEWS];
+}
+multiview_data;
+#endif
+
 /* clang-format off */
 
 #GLOBALS
@@ -530,8 +554,13 @@ uniform highp samplerCubeShadow positional_shadow; // texunit:-4
 
 #endif // !defined(DISABLE_LIGHT_OMNI) && !defined(DISABLE_LIGHT_SPOT)
 
-uniform highp sampler2D screen_texture; // texunit:-5
+#ifdef USE_MULTIVIEW
+uniform highp sampler2DArray depth_buffer; // texunit:-6
+uniform highp sampler2DArray screen_texture; // texunit:-5
+#else
 uniform highp sampler2D depth_buffer; // texunit:-6
+uniform highp sampler2D screen_texture; // texunit:-5
+#endif
 
 uniform highp mat4 world_transform;
 uniform mediump float opaque_prepass_threshold;
@@ -884,7 +913,11 @@ vec4 fog_process(vec3 vertex) {
 void main() {
 	//lay out everything, whatever is unused is optimized away anyway
 	vec3 vertex = vertex_interp;
+#ifdef USE_MULTIVIEW
+	vec3 view = -normalize(vertex_interp - multiview_data.eye_offset[ViewIndex].xyz);
+#else
 	vec3 view = -normalize(vertex_interp);
+#endif
 	vec3 albedo = vec3(1.0);
 	vec3 backlight = vec3(0.0);
 	vec4 transmittance_color = vec4(0.0, 0.0, 0.0, 1.0);
diff --git a/drivers/gles3/shaders/tonemap.glsl b/drivers/gles3/shaders/tonemap.glsl
index a478cf9170..0b769e77f2 100644
--- a/drivers/gles3/shaders/tonemap.glsl
+++ b/drivers/gles3/shaders/tonemap.glsl
@@ -44,7 +44,11 @@ in vec2 uv_interp;
 
 layout(location = 0) out vec4 frag_color;
 
+#ifdef USE_MULTIVIEW
+uniform highp sampler2DArray source; //texunit:0
+#else
 uniform highp sampler2D source; //texunit:0
+#endif
 
 #if defined(USE_GLOW_LEVEL1) || defined(USE_GLOW_LEVEL2) || defined(USE_GLOW_LEVEL3) || defined(USE_GLOW_LEVEL4) || defined(USE_GLOW_LEVEL5) || defined(USE_GLOW_LEVEL6) || defined(USE_GLOW_LEVEL7)
 #define USING_GLOW // only use glow when at least one glow level is selected
@@ -191,10 +195,17 @@ vec3 apply_fxaa(vec3 color, vec2 uv_interp, vec2 pixel_size) {
 	const float FXAA_REDUCE_MUL = (1.0 / 8.0);
 	const float FXAA_SPAN_MAX = 8.0;
 
+#ifdef USE_MULTIVIEW
+	vec3 rgbNW = textureLod(source, vec3(uv_interp + vec2(-1.0, -1.0) * pixel_size, ViewIndex), 0.0).xyz;
+	vec3 rgbNE = textureLod(source, vec3(uv_interp + vec2(1.0, -1.0) * pixel_size, ViewIndex), 0.0).xyz;
+	vec3 rgbSW = textureLod(source, vec3(uv_interp + vec2(-1.0, 1.0) * pixel_size, ViewIndex), 0.0).xyz;
+	vec3 rgbSE = textureLod(source, vec3(uv_interp + vec2(1.0, 1.0) * pixel_size, ViewIndex), 0.0).xyz;
+#else
 	vec3 rgbNW = textureLod(source, uv_interp + vec2(-1.0, -1.0) * pixel_size, 0.0).xyz;
 	vec3 rgbNE = textureLod(source, uv_interp + vec2(1.0, -1.0) * pixel_size, 0.0).xyz;
 	vec3 rgbSW = textureLod(source, uv_interp + vec2(-1.0, 1.0) * pixel_size, 0.0).xyz;
 	vec3 rgbSE = textureLod(source, uv_interp + vec2(1.0, 1.0) * pixel_size, 0.0).xyz;
+#endif
 	vec3 rgbM = color;
 	vec3 luma = vec3(0.299, 0.587, 0.114);
 	float lumaNW = dot(rgbNW, luma);
@@ -219,8 +230,13 @@ vec3 apply_fxaa(vec3 color, vec2 uv_interp, vec2 pixel_size) {
 						  dir * rcpDirMin)) *
 			pixel_size;
 
+#ifdef USE_MULTIVIEW
+	vec3 rgbA = 0.5 * (textureLod(source, vec3(uv_interp + dir * (1.0 / 3.0 - 0.5), ViewIndex), 0.0).xyz + textureLod(source, vec3(uv_interp + dir * (2.0 / 3.0 - 0.5), ViewIndex), 0.0).xyz);
+	vec3 rgbB = rgbA * 0.5 + 0.25 * (textureLod(source, vec3(uv_interp + dir * -0.5, ViewIndex), 0.0).xyz + textureLod(source, vec3(uv_interp + dir * 0.5, ViewIndex), 0.0).xyz);
+#else
 	vec3 rgbA = 0.5 * (textureLod(source, uv_interp + dir * (1.0 / 3.0 - 0.5), 0.0).xyz + textureLod(source, uv_interp + dir * (2.0 / 3.0 - 0.5), 0.0).xyz);
 	vec3 rgbB = rgbA * 0.5 + 0.25 * (textureLod(source, uv_interp + dir * -0.5, 0.0).xyz + textureLod(source, uv_interp + dir * 0.5, 0.0).xyz);
+#endif
 
 	float lumaB = dot(rgbB, luma);
 	if ((lumaB < lumaMin) || (lumaB > lumaMax)) {
@@ -231,7 +247,11 @@ vec3 apply_fxaa(vec3 color, vec2 uv_interp, vec2 pixel_size) {
 }
 
 void main() {
+#ifdef USE_MULTIVIEW
+	vec4 color = textureLod(source, vec3(uv_interp, ViewIndex), 0.0);
+#else
 	vec4 color = textureLod(source, uv_interp, 0.0);
+#endif
 
 #ifdef USE_FXAA
 	color.rgb = apply_fxaa(color.rgb, uv_interp, pixel_size);
diff --git a/drivers/gles3/storage/config.cpp b/drivers/gles3/storage/config.cpp
index 242c1ce0a9..609ecacded 100644
--- a/drivers/gles3/storage/config.cpp
+++ b/drivers/gles3/storage/config.cpp
@@ -34,6 +34,15 @@
 #include "core/config/project_settings.h"
 #include "core/templates/vector.h"
 
+#ifdef ANDROID_ENABLED
+#include <GLES3/gl3.h>
+#include <GLES3/gl3ext.h>
+#include <GLES3/gl3platform.h>
+
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+#endif
+
 using namespace GLES3;
 
 #define _GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT 0x84FF
@@ -98,6 +107,16 @@ Config::Config() {
 		anisotropic_level = MIN(float(1 << int(ProjectSettings::get_singleton()->get("rendering/textures/default_filters/anisotropic_filtering_level"))), anisotropic_level);
 	}
 
+	multiview_supported = extensions.has("GL_OVR_multiview2") || extensions.has("GL_OVR_multiview");
+#ifdef ANDROID_ENABLED
+	if (multiview_supported) {
+		eglFramebufferTextureMultiviewOVR = (PFNGLFRAMEBUFFERTEXTUREMULTIVIEWOVRPROC)eglGetProcAddress("glFramebufferTextureMultiviewOVR");
+		if (eglFramebufferTextureMultiviewOVR == nullptr) {
+			multiview_supported = false;
+		}
+	}
+#endif
+
 	force_vertex_shading = false; //GLOBAL_GET("rendering/quality/shading/force_vertex_shading");
 	use_nearest_mip_filter = GLOBAL_GET("rendering/textures/default_filters/use_nearest_mipmap_filter");
 
diff --git a/drivers/gles3/storage/config.h b/drivers/gles3/storage/config.h
index fe18345775..de08385e04 100644
--- a/drivers/gles3/storage/config.h
+++ b/drivers/gles3/storage/config.h
@@ -44,6 +44,10 @@
 #include OPENGL_INCLUDE_H
 #endif
 
+#ifdef ANDROID_ENABLED
+typedef void (*PFNGLFRAMEBUFFERTEXTUREMULTIVIEWOVRPROC)(GLenum, GLenum, GLuint, GLint, GLint, GLsizei);
+#endif
+
 namespace GLES3 {
 
 class Config {
@@ -82,6 +86,11 @@ public:
 	bool support_anisotropic_filter = false;
 	float anisotropic_level = 0.0f;
 
+	bool multiview_supported = false;
+#ifdef ANDROID_ENABLED
+	PFNGLFRAMEBUFFERTEXTUREMULTIVIEWOVRPROC eglFramebufferTextureMultiviewOVR = nullptr;
+#endif
+
 	static Config *get_singleton() { return singleton; };
 
 	Config();
diff --git a/drivers/gles3/storage/render_scene_buffers_gles3.cpp b/drivers/gles3/storage/render_scene_buffers_gles3.cpp
index 9123984dc7..b8e4530f56 100644
--- a/drivers/gles3/storage/render_scene_buffers_gles3.cpp
+++ b/drivers/gles3/storage/render_scene_buffers_gles3.cpp
@@ -33,12 +33,17 @@
 #include "render_scene_buffers_gles3.h"
 #include "texture_storage.h"
 
+#ifdef ANDROID_ENABLED
+#define glFramebufferTextureMultiviewOVR GLES3::Config::get_singleton()->eglFramebufferTextureMultiviewOVR
+#endif
+
 RenderSceneBuffersGLES3::~RenderSceneBuffersGLES3() {
 	free_render_buffer_data();
 }
 
 void RenderSceneBuffersGLES3::configure(RID p_render_target, const Size2i p_internal_size, const Size2i p_target_size, float p_fsr_sharpness, float p_texture_mipmap_bias, RS::ViewportMSAA p_msaa, RenderingServer::ViewportScreenSpaceAA p_screen_space_aa, bool p_use_taa, bool p_use_debanding, uint32_t p_view_count) {
 	GLES3::TextureStorage *texture_storage = GLES3::TextureStorage::get_singleton();
+	GLES3::Config *config = GLES3::Config::get_singleton();
 
 	//internal_size.x = p_internal_size.x; // ignore for now
 	//internal_size.y = p_internal_size.y;
@@ -50,7 +55,7 @@ void RenderSceneBuffersGLES3::configure(RID p_render_target, const Size2i p_inte
 	//msaa = p_msaa;
 	//screen_space_aa = p_screen_space_aa;
 	//use_debanding = p_use_debanding;
-	//view_count = p_view_count;
+	view_count = p_view_count;
 
 	free_render_buffer_data();
 
@@ -62,24 +67,43 @@ void RenderSceneBuffersGLES3::configure(RID p_render_target, const Size2i p_inte
 	glGenFramebuffers(1, &framebuffer);
 	glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
 
-	glBindTexture(GL_TEXTURE_2D, rt->color);
-	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, rt->color, 0);
+	if (view_count > 1 && config->multiview_supported) {
+		glBindTexture(GL_TEXTURE_2D_ARRAY, rt->color);
+		glFramebufferTextureMultiviewOVR(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, rt->color, 0, 0, view_count);
+	} else {
+		glBindTexture(GL_TEXTURE_2D, rt->color);
+		glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, rt->color, 0);
+	}
 
 	glGenTextures(1, &depth_texture);
-	glBindTexture(GL_TEXTURE_2D, depth_texture);
-
-	glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT24, rt->size.x, rt->size.y, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, nullptr);
-
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+	if (view_count > 1 && config->multiview_supported) {
+		glBindTexture(GL_TEXTURE_2D_ARRAY, depth_texture);
+		glTexImage3D(GL_TEXTURE_2D_ARRAY, 0, GL_DEPTH_COMPONENT24, rt->size.x, rt->size.y, view_count, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, nullptr);
+
+		glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+		glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+		glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+		glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+	} else {
+		glBindTexture(GL_TEXTURE_2D, depth_texture);
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT24, rt->size.x, rt->size.y, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, nullptr);
+
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+	}
 
-	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depth_texture, 0);
+	if (view_count > 1 && config->multiview_supported) {
+		glFramebufferTextureMultiviewOVR(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, depth_texture, 0, 0, view_count);
+	} else {
+		glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depth_texture, 0);
+	}
 
 	GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
 
 	glBindTexture(GL_TEXTURE_2D, 0);
+	glBindTexture(GL_TEXTURE_2D_ARRAY, 0);
 	glBindFramebuffer(GL_FRAMEBUFFER, texture_storage->system_fbo);
 
 	if (status != GL_FRAMEBUFFER_COMPLETE) {
diff --git a/drivers/gles3/storage/render_scene_buffers_gles3.h b/drivers/gles3/storage/render_scene_buffers_gles3.h
index ad0d2032b0..dbedbd22c3 100644
--- a/drivers/gles3/storage/render_scene_buffers_gles3.h
+++ b/drivers/gles3/storage/render_scene_buffers_gles3.h
@@ -56,7 +56,7 @@ public:
 	RS::ViewportMSAA msaa = RS::VIEWPORT_MSAA_DISABLED;
 	//RS::ViewportScreenSpaceAA screen_space_aa = RS::VIEWPORT_SCREEN_SPACE_AA_DISABLED;
 	//bool use_debanding = false;
-	//uint32_t view_count = 1;
+	uint32_t view_count = 1;
 
 	bool is_transparent = false;
 
diff --git a/drivers/gles3/storage/texture_storage.cpp b/drivers/gles3/storage/texture_storage.cpp
index 554b4165fa..524ff14cc9 100644
--- a/drivers/gles3/storage/texture_storage.cpp
+++ b/drivers/gles3/storage/texture_storage.cpp
@@ -34,6 +34,10 @@
 #include "config.h"
 #include "drivers/gles3/effects/copy_effects.h"
 
+#ifdef ANDROID_ENABLED
+#define glFramebufferTextureMultiviewOVR GLES3::Config::get_singleton()->eglFramebufferTextureMultiviewOVR
+#endif
+
 using namespace GLES3;
 
 TextureStorage *TextureStorage::singleton = nullptr;
@@ -720,8 +724,7 @@ void TextureStorage::texture_proxy_initialize(RID p_texture, RID p_base) {
 }
 
 void TextureStorage::texture_2d_update(RID p_texture, const Ref<Image> &p_image, int p_layer) {
-	// only 1 layer so far
-	texture_set_data(p_texture, p_image);
+	texture_set_data(p_texture, p_image, p_layer);
 #ifdef TOOLS_ENABLED
 	Texture *tex = texture_owner.get_or_null(p_texture);
 
@@ -1012,7 +1015,7 @@ void TextureStorage::texture_set_data(RID p_texture, const Ref<Image> &p_image,
 		img->resize_to_po2(false);
 	}
 
-	GLenum blit_target = (texture->target == GL_TEXTURE_CUBE_MAP) ? _cube_side_enum[p_layer] : GL_TEXTURE_2D;
+	GLenum blit_target = (texture->target == GL_TEXTURE_CUBE_MAP) ? _cube_side_enum[p_layer] : texture->target;
 
 	Vector<uint8_t> read = img->get_data();
 
@@ -1069,7 +1072,11 @@ void TextureStorage::texture_set_data(RID p_texture, const Ref<Image> &p_image,
 			glCompressedTexImage2D(blit_target, i, internal_format, bw, bh, 0, size, &read[ofs]);
 		} else {
 			glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
-			glTexImage2D(blit_target, i, internal_format, w, h, 0, format, type, &read[ofs]);
+			if (texture->target == GL_TEXTURE_2D_ARRAY) {
+				glTexSubImage3D(GL_TEXTURE_2D_ARRAY, i, 0, 0, p_layer, w, h, 0, format, type, &read[ofs]);
+			} else {
+				glTexImage2D(blit_target, i, internal_format, w, h, 0, format, type, &read[ofs]);
+			}
 		}
 
 		tsize += size;
@@ -1425,6 +1432,8 @@ void TextureStorage::_update_render_target(RenderTarget *rt) {
 		return;
 	}
 
+	Config *config = Config::get_singleton();
+
 	rt->color_internal_format = rt->is_transparent ? GL_RGBA8 : GL_RGB10_A2;
 	rt->color_format = GL_RGBA;
 	rt->color_type = rt->is_transparent ? GL_UNSIGNED_BYTE : GL_UNSIGNED_INT_2_10_10_10_REV;
@@ -1446,17 +1455,29 @@ void TextureStorage::_update_render_target(RenderTarget *rt) {
 
 		// color
 		glGenTextures(1, &rt->color);
-		glBindTexture(GL_TEXTURE_2D, rt->color);
-
-		glTexImage2D(GL_TEXTURE_2D, 0, rt->color_internal_format, rt->size.x, rt->size.y, 0, rt->color_format, rt->color_type, nullptr);
-
-		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+		if (rt->view_count > 1 && config->multiview_supported) {
+			glBindTexture(GL_TEXTURE_2D_ARRAY, rt->color);
+			glTexImage3D(GL_TEXTURE_2D_ARRAY, 0, rt->color_internal_format, rt->size.x, rt->size.y, rt->view_count, 0, rt->color_format, rt->color_type, nullptr);
+
+			glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+			glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+			glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+			glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+		} else {
+			glBindTexture(GL_TEXTURE_2D, rt->color);
+			glTexImage2D(GL_TEXTURE_2D, 0, rt->color_internal_format, rt->size.x, rt->size.y, 0, rt->color_format, rt->color_type, nullptr);
 
-		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
-		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+		}
 
-		glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, rt->color, 0);
+		if (rt->view_count > 1 && config->multiview_supported) {
+			glFramebufferTextureMultiviewOVR(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, rt->color, 0, 0, rt->view_count);
+		} else {
+			glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, rt->color, 0);
+		}
 
 		GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
 
@@ -1475,8 +1496,15 @@ void TextureStorage::_update_render_target(RenderTarget *rt) {
 
 		texture->format = rt->image_format;
 		texture->real_format = rt->image_format;
-		texture->type = Texture::TYPE_2D;
-		texture->target = GL_TEXTURE_2D;
+		if (rt->view_count > 1 && config->multiview_supported) {
+			texture->type = Texture::TYPE_LAYERED;
+			texture->target = GL_TEXTURE_2D_ARRAY;
+			texture->layers = rt->view_count;
+		} else {
+			texture->type = Texture::TYPE_2D;
+			texture->target = GL_TEXTURE_2D;
+			texture->layers = 1;
+		}
 		texture->gl_format_cache = rt->color_format;
 		texture->gl_type_cache = GL_UNSIGNED_BYTE;
 		texture->gl_internal_format_cache = rt->color_internal_format;
@@ -1619,13 +1647,14 @@ void TextureStorage::render_target_set_size(RID p_render_target, int p_width, in
 	RenderTarget *rt = render_target_owner.get_or_null(p_render_target);
 	ERR_FAIL_COND(!rt);
 
-	if (p_width == rt->size.x && p_height == rt->size.y) {
+	if (p_width == rt->size.x && p_height == rt->size.y && p_view_count == rt->view_count) {
 		return;
 	}
 
 	_clear_render_target(rt);
 
 	rt->size = Size2i(p_width, p_height);
+	rt->view_count = p_view_count;
 
 	_update_render_target(rt);
 }
diff --git a/drivers/gles3/storage/texture_storage.h b/drivers/gles3/storage/texture_storage.h
index 39a74236e5..dbe39428ac 100644
--- a/drivers/gles3/storage/texture_storage.h
+++ b/drivers/gles3/storage/texture_storage.h
@@ -324,6 +324,7 @@ private:
 struct RenderTarget {
 	Point2i position = Point2i(0, 0);
 	Size2i size = Size2i(0, 0);
+	uint32_t view_count = 1;
 	int mipmap_count = 1;
 	RID self;
 	GLuint fbo = 0;