Implementing OpenXR driver

3 files changed, 83 insertions, 9 deletions

diff --git a/servers/rendering/renderer_rd/effects_rd.cpp b/servers/rendering/renderer_rd/effects_rd.cpp
index f16a4b1d19..7883a2d816 100644
--- a/servers/rendering/renderer_rd/effects_rd.cpp
+++ b/servers/rendering/renderer_rd/effects_rd.cpp
@@ -332,7 +332,7 @@ void EffectsRD::copy_to_atlas_fb(RID p_source_rd_texture, RID p_dest_framebuffer
 	RD::get_singleton()->draw_list_draw(draw_list, true);
 }
 
-void EffectsRD::copy_to_fb_rect(RID p_source_rd_texture, RID p_dest_framebuffer, const Rect2i &p_rect, bool p_flip_y, bool p_force_luminance, bool p_alpha_to_zero, bool p_srgb, RID p_secondary) {
+void EffectsRD::copy_to_fb_rect(RID p_source_rd_texture, RID p_dest_framebuffer, const Rect2i &p_rect, bool p_flip_y, bool p_force_luminance, bool p_alpha_to_zero, bool p_srgb, RID p_secondary, bool p_multiview) {
 	memset(&copy_to_fb.push_constant, 0, sizeof(CopyToFbPushConstant));
 
 	if (p_flip_y) {
@@ -348,10 +348,18 @@ void EffectsRD::copy_to_fb_rect(RID p_source_rd_texture, RID p_dest_framebuffer,
 		copy_to_fb.push_constant.srgb = true;
 	}
 
+	CopyToFBMode mode;
+	if (p_multiview) {
+		mode = p_secondary.is_valid() ? COPY_TO_FB_MULTIVIEW_WITH_DEPTH : COPY_TO_FB_MULTIVIEW;
+	} else {
+		mode = p_secondary.is_valid() ? COPY_TO_FB_COPY2 : COPY_TO_FB_COPY;
+	}
+
 	RD::DrawListID draw_list = RD::get_singleton()->draw_list_begin(p_dest_framebuffer, RD::INITIAL_ACTION_KEEP, RD::FINAL_ACTION_READ, RD::INITIAL_ACTION_KEEP, RD::FINAL_ACTION_DISCARD, Vector<Color>(), 1.0, 0, p_rect);
-	RD::get_singleton()->draw_list_bind_render_pipeline(draw_list, copy_to_fb.pipelines[p_secondary.is_valid() ? COPY_TO_FB_COPY2 : COPY_TO_FB_COPY].get_render_pipeline(RD::INVALID_ID, RD::get_singleton()->framebuffer_get_format(p_dest_framebuffer)));
+	RD::get_singleton()->draw_list_bind_render_pipeline(draw_list, copy_to_fb.pipelines[mode].get_render_pipeline(RD::INVALID_ID, RD::get_singleton()->framebuffer_get_format(p_dest_framebuffer)));
 	RD::get_singleton()->draw_list_bind_uniform_set(draw_list, _get_uniform_set_from_texture(p_source_rd_texture), 0);
 	if (p_secondary.is_valid()) {
+		// TODO may need to do this differently when reading from depth buffer for multiview
 		RD::get_singleton()->draw_list_bind_uniform_set(draw_list, _get_uniform_set_from_texture(p_secondary), 1);
 	}
 	RD::get_singleton()->draw_list_bind_index_array(draw_list, index_array);
@@ -2367,15 +2375,26 @@ EffectsRD::EffectsRD(bool p_prefer_raster_effects) {
 		copy_modes.push_back("\n");
 		copy_modes.push_back("\n#define MODE_PANORAMA_TO_DP\n");
 		copy_modes.push_back("\n#define MODE_TWO_SOURCES\n");
+		copy_modes.push_back("\n#define MULTIVIEW\n");
+		copy_modes.push_back("\n#define MULTIVIEW\n#define MODE_TWO_SOURCES\n");
 
 		copy_to_fb.shader.initialize(copy_modes);
 
+		if (!RendererCompositorRD::singleton->is_xr_enabled()) {
+			copy_to_fb.shader.set_variant_enabled(COPY_TO_FB_MULTIVIEW, false);
+			copy_to_fb.shader.set_variant_enabled(COPY_TO_FB_MULTIVIEW_WITH_DEPTH, false);
+		}
+
 		copy_to_fb.shader_version = copy_to_fb.shader.version_create();
 
 		//use additive
 
 		for (int i = 0; i < COPY_TO_FB_MAX; i++) {
-			copy_to_fb.pipelines[i].setup(copy_to_fb.shader.version_get_shader(copy_to_fb.shader_version, i), RD::RENDER_PRIMITIVE_TRIANGLES, RD::PipelineRasterizationState(), RD::PipelineMultisampleState(), RD::PipelineDepthStencilState(), RD::PipelineColorBlendState::create_disabled(), 0);
+			if (copy_to_fb.shader.is_variant_enabled(i)) {
+				copy_to_fb.pipelines[i].setup(copy_to_fb.shader.version_get_shader(copy_to_fb.shader_version, i), RD::RENDER_PRIMITIVE_TRIANGLES, RD::PipelineRasterizationState(), RD::PipelineMultisampleState(), RD::PipelineDepthStencilState(), RD::PipelineColorBlendState::create_disabled(), 0);
+			} else {
+				copy_to_fb.pipelines[i].clear();
+			}
 		}
 	}
 
diff --git a/servers/rendering/renderer_rd/effects_rd.h b/servers/rendering/renderer_rd/effects_rd.h
index f5e5b1ace7..eca5e09800 100644
--- a/servers/rendering/renderer_rd/effects_rd.h
+++ b/servers/rendering/renderer_rd/effects_rd.h
@@ -203,6 +203,9 @@ private:
 		COPY_TO_FB_COPY,
 		COPY_TO_FB_COPY_PANORAMA_TO_DP,
 		COPY_TO_FB_COPY2,
+
+		COPY_TO_FB_MULTIVIEW,
+		COPY_TO_FB_MULTIVIEW_WITH_DEPTH,
 		COPY_TO_FB_MAX,
 
 	};
@@ -893,7 +896,7 @@ public:
 	bool get_prefer_raster_effects();
 
 	void fsr_upscale(RID p_source_rd_texture, RID p_secondary_texture, RID p_destination_texture, const Size2i &p_internal_size, const Size2i &p_size, float p_fsr_upscale_sharpness);
-	void copy_to_fb_rect(RID p_source_rd_texture, RID p_dest_framebuffer, const Rect2i &p_rect, bool p_flip_y = false, bool p_force_luminance = false, bool p_alpha_to_zero = false, bool p_srgb = false, RID p_secondary = RID());
+	void copy_to_fb_rect(RID p_source_rd_texture, RID p_dest_framebuffer, const Rect2i &p_rect, bool p_flip_y = false, bool p_force_luminance = false, bool p_alpha_to_zero = false, bool p_srgb = false, RID p_secondary = RID(), bool p_multiview = false);
 	void copy_to_rect(RID p_source_rd_texture, RID p_dest_texture, const Rect2i &p_rect, bool p_flip_y = false, bool p_force_luminance = false, bool p_all_source = false, bool p_8_bit_dst = false, bool p_alpha_to_one = false);
 	void copy_cubemap_to_panorama(RID p_source_cube, RID p_dest_panorama, const Size2i &p_panorama_size, float p_lod, bool p_is_array);
 	void copy_depth_to_rect(RID p_source_rd_texture, RID p_dest_framebuffer, const Rect2i &p_rect, bool p_flip_y = false);
diff --git a/servers/rendering/renderer_rd/shaders/copy_to_fb.glsl b/servers/rendering/renderer_rd/shaders/copy_to_fb.glsl
index 2f1f9c4765..9787c9879d 100644
--- a/servers/rendering/renderer_rd/shaders/copy_to_fb.glsl
+++ b/servers/rendering/renderer_rd/shaders/copy_to_fb.glsl
@@ -4,7 +4,20 @@
 
 #VERSION_DEFINES
 
+#ifdef MULTIVIEW
+#ifdef has_VK_KHR_multiview
+#extension GL_EXT_multiview : enable
+#define ViewIndex gl_ViewIndex
+#else // has_VK_KHR_multiview
+#define ViewIndex 0
+#endif // has_VK_KHR_multiview
+#endif //MULTIVIEW
+
+#ifdef MULTIVIEW
+layout(location = 0) out vec3 uv_interp;
+#else
 layout(location = 0) out vec2 uv_interp;
+#endif
 
 layout(push_constant, std430) uniform Params {
 	vec4 section;
@@ -19,9 +32,11 @@ params;
 
 void main() {
 	vec2 base_arr[4] = vec2[](vec2(0.0, 0.0), vec2(0.0, 1.0), vec2(1.0, 1.0), vec2(1.0, 0.0));
-	uv_interp = base_arr[gl_VertexIndex];
-
-	vec2 vpos = uv_interp;
+	uv_interp.xy = base_arr[gl_VertexIndex];
+#ifdef MULTIVIEW
+	uv_interp.z = ViewIndex;
+#endif
+	vec2 vpos = uv_interp.xy;
 	if (params.use_section) {
 		vpos = params.section.xy + vpos * params.section.zw;
 	}
@@ -39,6 +54,15 @@ void main() {
 
 #VERSION_DEFINES
 
+#ifdef MULTIVIEW
+#ifdef has_VK_KHR_multiview
+#extension GL_EXT_multiview : enable
+#define ViewIndex gl_ViewIndex
+#else // has_VK_KHR_multiview
+#define ViewIndex 0
+#endif // has_VK_KHR_multiview
+#endif //MULTIVIEW
+
 layout(push_constant, std430) uniform Params {
 	vec4 section;
 	vec2 pixel_size;
@@ -52,12 +76,25 @@ layout(push_constant, std430) uniform Params {
 }
 params;
 
+#ifdef MULTIVIEW
+layout(location = 0) in vec3 uv_interp;
+#else
 layout(location = 0) in vec2 uv_interp;
+#endif
 
+#ifdef MULTIVIEW
+layout(set = 0, binding = 0) uniform sampler2DArray source_color;
+#ifdef MODE_TWO_SOURCES
+layout(set = 1, binding = 0) uniform sampler2DArray source_depth;
+layout(location = 1) out float depth;
+#endif /* MODE_TWO_SOURCES */
+#else
 layout(set = 0, binding = 0) uniform sampler2D source_color;
 #ifdef MODE_TWO_SOURCES
 layout(set = 1, binding = 0) uniform sampler2D source_color2;
-#endif
+#endif /* MODE_TWO_SOURCES */
+#endif /* MULTIVIEW */
+
 layout(location = 0) out vec4 frag_color;
 
 vec3 linear_to_srgb(vec3 color) {
@@ -68,9 +105,14 @@ vec3 linear_to_srgb(vec3 color) {
 }
 
 void main() {
+#ifdef MULTIVIEW
+	vec3 uv = uv_interp;
+#else
 	vec2 uv = uv_interp;
+#endif
 
 #ifdef MODE_PANORAMA_TO_DP
+	// Note, multiview and panorama should not be mixed at this time
 
 	//obtain normal from dual paraboloid uv
 #define M_PI 3.14159265359
@@ -98,10 +140,20 @@ void main() {
 		uv = 1.0 - uv;
 	}
 #endif
+
+#ifdef MULTIVIEW
+	vec4 color = textureLod(source_color, uv, 0.0);
+#ifdef MODE_TWO_SOURCES
+	// In multiview our 2nd input will be our depth map
+	depth = textureLod(source_depth, uv, 0.0).r;
+#endif /* MODE_TWO_SOURCES */
+
+#else
 	vec4 color = textureLod(source_color, uv, 0.0);
 #ifdef MODE_TWO_SOURCES
 	color += textureLod(source_color2, uv, 0.0);
-#endif
+#endif /* MODE_TWO_SOURCES */
+#endif /* MULTIVIEW */
 	if (params.force_luminance) {
 		color.rgb = vec3(max(max(color.r, color.g), color.b));
 	}