Vulkan: parity with GL (P1–P7), shared GPU culling records (N6c), threaded command recording and render thread (M1, M4)

shaders/vk14/clouds_shadow.comp

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+#version 460 core
+#define STAGE_COMPUTE 1
+// the shadow the clouds cast on the ground: for points of the ground reference around the camera, what the clouds let through
+// towards the key light. the shading (light_common.glsl) and the fog (fog_inject.comp) look it up along the ray of the sun,
+// see cloud_shadow() in weather_common.glsl
+
+#define LAYOUT_COMPUTE 1
+#include "common.glsl"
+#include "clouds_common.glsl"
+
+layout(local_size_x = WEATHER_GROUP_SIZE, local_size_y = WEATHER_GROUP_SIZE, local_size_z = 1) in;
+
+layout(r16f, set = COMPUTE_SET, binding = 0) uniform writeonly image2D shadow;
+
+// the parameters of the kernel (push constants)
+layout(push_constant) uniform kernel_constants
+{
+	int size;
+	// world x and z of the centre of the map relative to the camera, size of the map (metres)
+	vec3 placement;
+	// samples through a layer
+	int steps;
+};
+
+void main()
+{
+	ivec2 texel = ivec2(gl_GlobalInvocationID.xy);
+	if (any(greaterThanEqual(texel, ivec2(size))))
+		return;
+	vec2 offset = placement.xy + ((vec2(texel) + 0.5) / float(size) - 0.5) * placement.z;
+	// the ground reference, the earth curving away
+	vec3 ground = vec3(offset.x, -weather_camera.x + dot(offset, offset) * (0.5 / CLOUD_EARTH_RADIUS), offset.y);
+	imageStore(shadow, texel, vec4(cloud_transmittance_to_sun(ground, steps)));
+}