Add stereoscopic rendering through multiview

4 files changed, 103 insertions, 7 deletions

diff --git a/servers/rendering/renderer_rd/shaders/scene_forward_mobile.glsl b/servers/rendering/renderer_rd/shaders/scene_forward_mobile.glsl
index 23edc47f88..aa8a0b96c5 100644
--- a/servers/rendering/renderer_rd/shaders/scene_forward_mobile.glsl
+++ b/servers/rendering/renderer_rd/shaders/scene_forward_mobile.glsl
@@ -96,6 +96,18 @@ layout(location = 8) out float dp_clip;
 
 #endif
 
+#ifdef USE_MULTIVIEW
+#ifdef has_VK_KHR_multiview
+#define ViewIndex gl_ViewIndex
+#else
+// !BAS! This needs to become an input once we implement our fallback!
+#define ViewIndex 0
+#endif
+#else
+// Set to zero, not supported in non stereo
+#define ViewIndex 0
+#endif //USE_MULTIVIEW
+
 invariant gl_Position;
 
 #GLOBALS
@@ -234,7 +246,13 @@ void main() {
 	vec4 position;
 #endif
 
+#ifdef USE_MULTIVIEW
+	mat4 projection_matrix = scene_data.projection_matrix_view[ViewIndex];
+	mat4 inv_projection_matrix = scene_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
 
 //using world coordinates
 #if !defined(SKIP_TRANSFORM_USED) && defined(VERTEX_WORLD_COORDS_USED)
@@ -386,10 +404,26 @@ layout(location = 8) in float dp_clip;
 
 #endif
 
+#ifdef USE_MULTIVIEW
+#ifdef has_VK_KHR_multiview
+#define ViewIndex gl_ViewIndex
+#else
+// !BAS! This needs to become an input once we implement our fallback!
+#define ViewIndex 0
+#endif
+#else
+// Set to zero, not supported in non stereo
+#define ViewIndex 0
+#endif //USE_MULTIVIEW
+
 //defines to keep compatibility with vertex
 
 #define world_matrix draw_call.transform
+#ifdef USE_MULTIVIEW
+#define projection_matrix scene_data.projection_matrix_view[ViewIndex]
+#else
 #define projection_matrix scene_data.projection_matrix
+#endif
 
 #if defined(ENABLE_SSS) && defined(ENABLE_TRANSMITTANCE)
 //both required for transmittance to be enabled
diff --git a/servers/rendering/renderer_rd/shaders/scene_forward_mobile_inc.glsl b/servers/rendering/renderer_rd/shaders/scene_forward_mobile_inc.glsl
index 656a764a89..7fcd84695d 100644
--- a/servers/rendering/renderer_rd/shaders/scene_forward_mobile_inc.glsl
+++ b/servers/rendering/renderer_rd/shaders/scene_forward_mobile_inc.glsl
@@ -1,4 +1,9 @@
 #define M_PI 3.14159265359
+#define MAX_VIEWS 2
+
+#if defined(USE_MULTIVIEW) && defined(has_VK_KHR_multiview)
+#extension GL_EXT_multiview : enable
+#endif
 
 #include "decal_data_inc.glsl"
 
@@ -121,10 +126,13 @@ global_variables;
 layout(set = 1, binding = 0, std140) uniform SceneData {
 	mat4 projection_matrix;
 	mat4 inv_projection_matrix;
-
 	mat4 camera_matrix;
 	mat4 inv_camera_matrix;
 
+	// only used for multiview
+	mat4 projection_matrix_view[MAX_VIEWS];
+	mat4 inv_projection_matrix_view[MAX_VIEWS];
+
 	vec2 viewport_size;
 	vec2 screen_pixel_size;
 
diff --git a/servers/rendering/renderer_rd/shaders/sky.glsl b/servers/rendering/renderer_rd/shaders/sky.glsl
index 9924da37d5..41c6325bc5 100644
--- a/servers/rendering/renderer_rd/shaders/sky.glsl
+++ b/servers/rendering/renderer_rd/shaders/sky.glsl
@@ -4,11 +4,17 @@
 
 #VERSION_DEFINES
 
+#define MAX_VIEWS 2
+
+#if defined(USE_MULTIVIEW) && defined(has_VK_KHR_multiview)
+#extension GL_EXT_multiview : enable
+#endif
+
 layout(location = 0) out vec2 uv_interp;
 
 layout(push_constant, binding = 1, std430) uniform Params {
 	mat3 orientation;
-	vec4 proj;
+	vec4 projections[MAX_VIEWS];
 	vec4 position_multiplier;
 	float time;
 }
@@ -26,15 +32,29 @@ void main() {
 
 #VERSION_DEFINES
 
+#ifdef USE_MULTIVIEW
+#ifdef has_VK_KHR_multiview
+#extension GL_EXT_multiview : enable
+#define ViewIndex gl_ViewIndex
+#else // has_VK_KHR_multiview
+// !BAS! This needs to become an input once we implement our fallback!
+#define ViewIndex 0
+#endif // has_VK_KHR_multiview
+#else // USE_MULTIVIEW
+// Set to zero, not supported in non stereo
+#define ViewIndex 0
+#endif //USE_MULTIVIEW
+
 #define M_PI 3.14159265359
+#define MAX_VIEWS 2
 
 layout(location = 0) in vec2 uv_interp;
 
 layout(push_constant, binding = 1, std430) uniform Params {
 	mat3 orientation;
-	vec4 proj;
+	vec4 projections[MAX_VIEWS];
 	vec4 position_multiplier;
-	float time; //TODO consider adding vec2 screen res, and float radiance size
+	float time;
 }
 params;
 
@@ -85,7 +105,6 @@ struct DirectionalLightData {
 layout(set = 0, binding = 3, std140) uniform DirectionalLights {
 	DirectionalLightData data[MAX_DIRECTIONAL_LIGHT_DATA_STRUCTS];
 }
-
 directional_lights;
 
 #ifdef MATERIAL_UNIFORMS_USED
@@ -154,8 +173,8 @@ vec4 fog_process(vec3 view, vec3 sky_color) {
 void main() {
 	vec3 cube_normal;
 	cube_normal.z = -1.0;
-	cube_normal.x = (cube_normal.z * (-uv_interp.x - params.proj.x)) / params.proj.y;
-	cube_normal.y = -(cube_normal.z * (-uv_interp.y - params.proj.z)) / params.proj.w;
+	cube_normal.x = (cube_normal.z * (-uv_interp.x - params.projections[ViewIndex].x)) / params.projections[ViewIndex].y;
+	cube_normal.y = -(cube_normal.z * (-uv_interp.y - params.projections[ViewIndex].z)) / params.projections[ViewIndex].w;
 	cube_normal = mat3(params.orientation) * cube_normal;
 	cube_normal.z = -cube_normal.z;
 	cube_normal = normalize(cube_normal);
diff --git a/servers/rendering/renderer_rd/shaders/tonemap.glsl b/servers/rendering/renderer_rd/shaders/tonemap.glsl
index 86b4da6b08..23f83b3b9c 100644
--- a/servers/rendering/renderer_rd/shaders/tonemap.glsl
+++ b/servers/rendering/renderer_rd/shaders/tonemap.glsl
@@ -4,6 +4,12 @@
 
 #VERSION_DEFINES
 
+#ifdef MULTIVIEW
+#ifdef has_VK_KHR_multiview
+#extension GL_EXT_multiview : enable
+#endif
+#endif
+
 layout(location = 0) out vec2 uv_interp;
 
 void main() {
@@ -18,9 +24,22 @@ 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(location = 0) in vec2 uv_interp;
 
+#ifdef MULTIVIEW
+layout(set = 0, binding = 0) uniform sampler2DArray source_color;
+#else
 layout(set = 0, binding = 0) uniform sampler2D source_color;
+#endif
 layout(set = 1, binding = 0) uniform sampler2D source_auto_exposure;
 layout(set = 2, binding = 0) uniform sampler2D source_glow;
 #ifdef USE_1D_LUT
@@ -277,10 +296,17 @@ vec3 do_fxaa(vec3 color, float exposure, vec2 uv_interp) {
 	const float FXAA_REDUCE_MUL = (1.0 / 8.0);
 	const float FXAA_SPAN_MAX = 8.0;
 
+#ifdef MULTIVIEW
+	vec3 rgbNW = textureLod(source_color, vec3(uv_interp + vec2(-1.0, -1.0) * params.pixel_size, ViewIndex), 0.0).xyz * exposure;
+	vec3 rgbNE = textureLod(source_color, vec3(uv_interp + vec2(1.0, -1.0) * params.pixel_size, ViewIndex), 0.0).xyz * exposure;
+	vec3 rgbSW = textureLod(source_color, vec3(uv_interp + vec2(-1.0, 1.0) * params.pixel_size, ViewIndex), 0.0).xyz * exposure;
+	vec3 rgbSE = textureLod(source_color, vec3(uv_interp + vec2(1.0, 1.0) * params.pixel_size, ViewIndex), 0.0).xyz * exposure;
+#else
 	vec3 rgbNW = textureLod(source_color, uv_interp + vec2(-1.0, -1.0) * params.pixel_size, 0.0).xyz * exposure;
 	vec3 rgbNE = textureLod(source_color, uv_interp + vec2(1.0, -1.0) * params.pixel_size, 0.0).xyz * exposure;
 	vec3 rgbSW = textureLod(source_color, uv_interp + vec2(-1.0, 1.0) * params.pixel_size, 0.0).xyz * exposure;
 	vec3 rgbSE = textureLod(source_color, uv_interp + vec2(1.0, 1.0) * params.pixel_size, 0.0).xyz * exposure;
+#endif
 	vec3 rgbM = color;
 	vec3 luma = vec3(0.299, 0.587, 0.114);
 	float lumaNW = dot(rgbNW, luma);
@@ -305,8 +331,13 @@ vec3 do_fxaa(vec3 color, float exposure, vec2 uv_interp) {
 						  dir * rcpDirMin)) *
 		  params.pixel_size;
 
+#ifdef MULTIVIEW
+	vec3 rgbA = 0.5 * exposure * (textureLod(source_color, vec3(uv_interp + dir * (1.0 / 3.0 - 0.5), ViewIndex), 0.0).xyz + textureLod(source_color, vec3(uv_interp + dir * (2.0 / 3.0 - 0.5), ViewIndex), 0.0).xyz);
+	vec3 rgbB = rgbA * 0.5 + 0.25 * exposure * (textureLod(source_color, vec3(uv_interp + dir * -0.5, ViewIndex), 0.0).xyz + textureLod(source_color, vec3(uv_interp + dir * 0.5, ViewIndex), 0.0).xyz);
+#else
 	vec3 rgbA = 0.5 * exposure * (textureLod(source_color, uv_interp + dir * (1.0 / 3.0 - 0.5), 0.0).xyz + textureLod(source_color, uv_interp + dir * (2.0 / 3.0 - 0.5), 0.0).xyz);
 	vec3 rgbB = rgbA * 0.5 + 0.25 * exposure * (textureLod(source_color, uv_interp + dir * -0.5, 0.0).xyz + textureLod(source_color, uv_interp + dir * 0.5, 0.0).xyz);
+#endif
 
 	float lumaB = dot(rgbB, luma);
 	if ((lumaB < lumaMin) || (lumaB > lumaMax)) {
@@ -329,7 +360,11 @@ vec3 screen_space_dither(vec2 frag_coord) {
 }
 
 void main() {
+#ifdef MULTIVIEW
+	vec3 color = textureLod(source_color, vec3(uv_interp, ViewIndex), 0.0f).rgb;
+#else
 	vec3 color = textureLod(source_color, uv_interp, 0.0f).rgb;
+#endif
 
 	// Exposure