diff options
| -rw-r--r-- | assets/shaders/Geodesic.slang | 363 | ||||
| -rw-r--r-- | src/platform/vulkan/vulkan_renderer.cpp | 162 |
2 files changed, 245 insertions, 280 deletions
diff --git a/assets/shaders/Geodesic.slang b/assets/shaders/Geodesic.slang index 9490f21..a0d030e 100644 --- a/assets/shaders/Geodesic.slang +++ b/assets/shaders/Geodesic.slang @@ -25,11 +25,11 @@ ConstantBuffer<Camera> cam; struct Disk { - float disk_r1; - float disk_r2; - float disk_num; - float thickness; - float disk_density; + float disk_r1; // inner edge (clamped to the ISCO, 3 r_s, below) + float disk_r2; // outer edge + float disk_num; // turbulence strength (0 = smooth physical disk) + float thickness; // unused by the thin-disk model; kept for UBO layout + float disk_density; // overall disk brightness / exposure }; ConstantBuffer<Disk> disk; @@ -53,16 +53,28 @@ ConstantBuffer<Simulation> sim; SamplerCube u_HDRIEnvironment; +// Schwarzschild radius of Sgr A* (metres). Geometric units with c = G = 1 are +// used throughout the geodesic integration; the black-hole mass is M = r_s / 2. static const float SagA_rs = 1.269e10; static const float D_LAMBDA = 1e7; static const float ESCAPE_R = 1e30; +static const float R_ISCO = 3.0 * SagA_rs; // innermost stable circular orbit (6M) +static const float R_PHOTON = 1.5 * SagA_rs; // photon sphere (3M) +static const float FLUX_PEAK = 0.0569; // peak of the r^-3(1-sqrt(r_in/r)) profile (at r/r_in ~ 1.36) + static const int DEFAULT_MAX_STEPS_MOVING = 12000; static const int DEFAULT_MAX_STEPS_STATIC = 8000; static const float DEFAULT_EARLY_EXIT_DISTANCE = 2e12; static const float MIN_STEP_SIZE = 1e6; -static const float MAX_STEP_SIZE = 5e7; +static const float MAX_STEP_SIZE = 2e10; + +// Display mapping for the (relative) Novikov-Thorne flux -> visible colour. +// The RADIAL PROFILE is physical; the absolute temperature scale is a display +// choice (a real Sgr A* disk is far cooler / redder than this). +static const float T_PEAK = 4800.0; // Kelvin at the flux peak (display scale) +static const float DISK_EXPOSURE = 0.9; // overall brightness of the disk struct Hit { @@ -76,21 +88,6 @@ float3 SampleHDRI(float3 direction) return u_HDRIEnvironment.Sample(direction).rgb; } -float hash(float p) -{ - p = frac(p * 0.1031); - p *= p + 33.33; - p *= p + p; - return frac(p); -} - -float hash(float2 p) -{ - float3 p3 = frac(float3(p.xyx) * float3(0.1031, 0.1030, 0.0973)); - p3 += dot(p3, p3.yzx + 33.33); - return frac((p3.x + p3.y) * p3.z); -} - float hash(float3 p) { p = frac(p * float3(0.1031, 0.1030, 0.0973)); @@ -102,7 +99,6 @@ float noise(float3 x) { float3 i = floor(x); float3 fr = frac(x); - float3 u = fr * fr * (3.0 - 2.0 * fr); float a = hash(i); @@ -122,62 +118,92 @@ float fbm(float3 x, int octaves) { float v = 0.0; float a = 0.5; - float f = 1.0; float3 shift = float3(100, 200, 300); - for (int i = 0; i < octaves; ++i) { - v += a * noise(x * f); + v += a * noise(x); x = x * 2.0 + shift; a *= 0.5; - f *= 2.0; } return v; } -float GetCloudDensity(float3 pos) +// Planckian-locus blackbody colour (Tanner Helland approximation), T in Kelvin. +// Returns an sRGB-ish chromaticity normalised so the brightest channel ~ 1. +float3 Blackbody(float T) { - float r_cyl = length(float2(pos.x, pos.z)); - float r_norm = (r_cyl - disk.disk_r1) / (disk.disk_r2 - disk.disk_r1); + T = clamp(T, 1000.0, 40000.0); + float t = T / 100.0; + float3 c; - if (r_norm < 0.0 || r_norm > 1.0) - return 0.0; + c.r = (t <= 66.0) ? 1.0 + : clamp(1.292936186 * pow(t - 60.0, -0.1332047592), 0.0, 1.0); - float h_norm = abs(pos.y) / disk.thickness; - float vertical_falloff = exp(-h_norm * h_norm * 3.0); - float radial_density = 1.0 - r_norm * 0.5; + c.g = (t <= 66.0) ? clamp(0.3900815788 * log(t) - 0.6318414438, 0.0, 1.0) + : clamp(1.1298908609 * pow(t - 60.0, -0.0755148492), 0.0, 1.0); - float keplerian_speed = 1.0 / sqrt(r_norm + 0.1); + c.b = (t >= 66.0) ? 1.0 + : (t <= 19.0) ? 0.0 + : clamp(0.5432067891 * log(t - 10.0) - 1.1962540891, 0.0, 1.0); + return c; +} - float rotation_angle = sim.time * keplerian_speed * 0.5; - float3 rotated_pos = float3( - pos.x * cos(rotation_angle) - pos.z * sin(rotation_angle), - pos.y, - pos.x * sin(rotation_angle) + pos.z * cos(rotation_angle) - ) * 1e-10; +// Emission from the thin accretion disk at an equatorial crossing point P, seen +// along the (backward-traced) ray direction rayDir. Combines a Novikov-Thorne +// temperature profile with the full gravitational + Doppler redshift. +// g = sqrt(1 - 3M/r) / (1 - beta . nhat) (verified: g -> sqrt(1/2) at ISCO) +// Brightness follows relativistic beaming (I_obs = g^4 I_emit); colour follows +// the redshifted blackbody at T_obs = g * T_emit. +float3 DiskEmission(float3 P, float3 rayDir) +{ + float rc = length(float2(P.x, P.z)); // cylindrical radius (disk axis = +Y) + float rin = max(disk.disk_r1, R_ISCO); + float rout = disk.disk_r2; + if (rc < rin || rc > rout) + return float3(0.0); - float large_turbulence = fbm(rotated_pos * 1.2, 5); - float medium_wisps = fbm(rotated_pos * 2.5, 4); - float small_detail = fbm(rotated_pos * 6.0, 3); - float fine_detail = fbm(rotated_pos * 10.0, 2); + // Novikov-Thorne-style radial flux: F(r) ~ r^-3 (1 - sqrt(r_in/r)), zero at + // the inner edge, peaking just outside it, then declining. T ~ F^(1/4). + float xr = rc / rin; + float flux = max((1.0 - sqrt(1.0 / xr)) / (xr * xr * xr), 0.0); + float Tn = pow(flux / FLUX_PEAK, 0.25); // normalised temperature, peak ~ 1 + float Temit = T_PEAK * Tn; - float noise_mask = large_turbulence * 0.4 + - medium_wisps * 0.3 + - small_detail * 0.2 + - fine_detail * 0.1; + // Keplerian orbit (prograde about +Y). Locally-measured orbital speed for a + // Schwarzschild circular geodesic: v = sqrt( M / (r - 2M) ) = 0.5 c at ISCO. + float3 rhat = normalize(float3(P.x, 0.0, P.z)); + float3 phiHat = normalize(cross(float3(0.0, 1.0, 0.0), rhat)); + float v = sqrt((SagA_rs * 0.5) / max(rc - SagA_rs, 1.0)); + float3 beta = v * phiHat; + float3 nhat = -normalize(rayDir); // photon direction toward the observer - noise_mask = smoothstep(0.25, 0.75, noise_mask); + float g = sqrt(max(1.0 - 1.5 * SagA_rs / rc, 0.0)) / max(1.0 - dot(beta, nhat), 1e-3); - float angle = atan2(pos.z, pos.x); - float rotated_angle = angle + sim.time * 0.5; + float Tobs = g * Temit; + float3 colour = Blackbody(Tobs); + // Physical bolometric intensity is ~ T_emit^4 * g^4, an enormous dynamic + // range. The g^4 relativistic beaming (the physical asymmetry) is kept; the + // radial falloff is display-compressed (Tn^2) so the colour gradient across + // the disk stays visible instead of collapsing to a thin saturated ring. + float bright = pow(Tn, 2.0) * pow(g, 4.0); - float spiral_arms = sin(rotated_angle * 3.0 + r_norm * 15.0) * 0.15 + 0.85; + // Soft inner/outer edges (disks have no hard rim); also tames rim aliasing. + float edge = smoothstep(rin, rin * 1.12, rc) * (1.0 - smoothstep(rout * 0.88, rout, rc)); + bright *= edge; - float orbital_angle = angle + sim.time * keplerian_speed * 0.8; - float orbital_pattern = sin(orbital_angle * 2.0 + r_norm * 8.0) * 0.2 + 0.8; + // Optional turbulence overlay (disk.disk_num = strength; 0 = smooth). + if (disk.disk_num > 0.0) + { + float ang = sim.time * 0.3 / sqrt(xr); + float3 rp = float3(P.x * cos(ang) - P.z * sin(ang), + 0.0, + P.x * sin(ang) + P.z * cos(ang)) * 1e-10; + float turb = 1.0 + disk.disk_num * (fbm(rp * 3.0, 3) - 0.5); + bright *= max(turb, 0.0); + } - float density = vertical_falloff * radial_density * noise_mask * spiral_arms * orbital_pattern; - return density * disk.disk_density; + float exposure = DISK_EXPOSURE * max(disk.disk_density, 0.0) * 10.0; + return colour * bright * exposure; } struct Ray @@ -198,18 +224,14 @@ Ray InitRay(float3 pos, float3 dir) ray.theta = acos(pos.z / ray.r); ray.phi = atan2(pos.y, pos.x); - float dx = dir.x; - float dy = dir.y; - float dz = dir.z; + float dx = dir.x, dy = dir.y, dz = dir.z; ray.dr = sin(ray.theta)*cos(ray.phi)*dx + sin(ray.theta)*sin(ray.phi)*dy + cos(ray.theta)*dz; - ray.dtheta = (cos(ray.theta)*cos(ray.phi)*dx + cos(ray.theta)*sin(ray.phi)*dy - sin(ray.theta)*dz) / ray.r; - ray.dphi = (-sin(ray.phi)*dx + cos(ray.phi)*dy) / (ray.r * sin(ray.theta)); @@ -217,31 +239,22 @@ Ray InitRay(float3 pos, float3 dir) float f = 1.0 - SagA_rs / ray.r; float dt_dL = sqrt((ray.dr*ray.dr)/f + ray.r*ray.r*(ray.dtheta*ray.dtheta + - sin(ray.theta)*sin(ray.theta)* - ray.dphi*ray.dphi)); + sin(ray.theta)*sin(ray.theta)*ray.dphi*ray.dphi)); ray.E = f * dt_dL; - return ray; } -bool Intercept(Ray ray, float rs) -{ - return ray.r <= rs; -} +bool Intercept(Ray ray, float rs) { return ray.r <= rs; } bool InterceptObject(Ray ray, inout Hit hit) { float3 P = float3(ray.x, ray.y, ray.z); - for (int i = 0; i < obj.numObjects; ++i) { float3 center = obj.objPosRadius[i].xyz; float radius = obj.objPosRadius[i].w; - float distSq = dot(P - center, P - center); - if (distSq > radius * radius * 4.0) - continue; - + if (distSq > radius * radius * 4.0) continue; if (distSq <= radius * radius) { hit.objectColor = obj.objColor[i]; @@ -250,7 +263,6 @@ bool InterceptObject(Ray ray, inout Hit hit) return true; } } - return false; } @@ -276,7 +288,6 @@ void RK4Step(inout Ray ray, float dL) { float3 k1a, k1b; GeodesicRHS(ray, k1a, k1b); - ray.r += dL * k1a.x; ray.theta += dL * k1a.y; ray.phi += dL * k1a.z; @@ -289,71 +300,19 @@ void RK4Step(inout Ray ray, float dL) ray.z = ray.r * cos(ray.theta); } -bool IsInDiskVolume(float3 pos) -{ - float r_cyl = length(float2(pos.x, pos.z)); - return (r_cyl >= disk.disk_r1 && r_cyl <= disk.disk_r2 && abs(pos.y) <= disk.thickness); -} - -float4 SampleDiskColor(float3 pos) +float CalculateAdaptiveStepSize(Ray ray, float baseStepSize) { - float r_cyl = length(float2(pos.x, pos.z)); - float r_norm = (r_cyl - disk.disk_r1) / (disk.disk_r2 - disk.disk_r1); - - float3 innerColor = float3(1.0, 0.9, 0.5); - float3 midColor = float3(1.0, 0.6, 0.2); - float3 outerColor = float3(0.9, 0.3, 0.1); - - float3 baseColor; - if (r_norm < 0.5) - baseColor = lerp(innerColor, midColor, r_norm * 2.0); - else - baseColor = lerp(midColor, outerColor, (r_norm - 0.5) * 2.0); - - float r_norm_rot = (r_cyl - disk.disk_r1) / (disk.disk_r2 - disk.disk_r1); - float keplerian_speed = 1.0 / sqrt(r_norm_rot + 0.1); - - float color_rotation_angle = sim.time * keplerian_speed * 0.3; - float3 rotated_color_pos = float3( - pos.x * cos(color_rotation_angle) - pos.z * sin(color_rotation_angle), - pos.y, - pos.x * sin(color_rotation_angle) + pos.z * cos(color_rotation_angle) - ) * 1e-10; - - float large_color = fbm(rotated_color_pos * 1.8, 4); - float medium_color = fbm(rotated_color_pos * 4.0, 3); - float small_color = fbm(rotated_color_pos * 8.0, 2); - float colorVariation = (large_color * 0.5 + medium_color * 0.3 + small_color * 0.2) * 0.6; - baseColor = baseColor * (1.0 + colorVariation); - - float density = GetCloudDensity(pos); - - float brightness_rotation_angle = sim.time * keplerian_speed * 0.7; - float3 rotated_brightness_pos = float3( - pos.x * cos(brightness_rotation_angle) - pos.z * sin(brightness_rotation_angle), - pos.y, - pos.x * sin(brightness_rotation_angle) + pos.z * cos(brightness_rotation_angle) - ) * 1e-10; - - float brightness_large = fbm(rotated_brightness_pos * 3.0, 3); - float brightness_medium = fbm(rotated_brightness_pos * 5.0, 2); - float brightness_small = fbm(rotated_brightness_pos * 7.0, 2); - float brightness_noise = (brightness_large * 0.6 + brightness_medium * 0.3 + brightness_small * 0.1); - - float baseBrightness = 1.0 + density * 1.5; - float glowBrightness = brightness_noise * 0.8; - float brightness = baseBrightness + glowBrightness; - - return float4(baseColor * brightness, density); + // Step proportional to the distance from the photon sphere: near-flat space + // far from the hole is crossed in a few huge steps, while the sharply curved + // region near the photon sphere is resolved with tiny ones. This keeps the + // integration accurate near the hole regardless of how far the camera is. + float step = 0.02 * max(ray.r - R_PHOTON, 0.0); + return clamp(step, MIN_STEP_SIZE, MAX_STEP_SIZE); } -float CalculateAdaptiveStepSize(Ray ray, float baseStepSize) +float3 ACESFilm(float3 x) { - float r_factor = clamp(ray.r / (SagA_rs * 10.0), 0.1, 1.0); - float curvature = length(float3(ray.dr, ray.dtheta * ray.r, ray.dphi * ray.r * sin(ray.theta))); - float curvature_factor = clamp(1e12 / (curvature + 1e6), 0.1, 2.0); - - return clamp(baseStepSize * r_factor * curvature_factor, MIN_STEP_SIZE, MAX_STEP_SIZE); + return clamp((x * (2.51 * x + 0.03)) / (x * (2.43 * x + 0.59) + 0.14), 0.0, 1.0); } [shader("fragment")] @@ -364,127 +323,79 @@ float4 fragmentMain(VSOutput input) : SV_Target float3 dir = normalize(u * cam.camRight - v * cam.camUp + cam.camForward); Ray ray = InitRay(cam.camPos, dir); - float4 color = float4(0.0, 0.0, 0.0, 0.0); - - bool hitBlackHole = false; - bool hitObject = false; - - Hit hit; - hit.objectColor = float4(0.0, 0.0, 0.0, 0.0); - hit.hitCenter = float3(0.0, 0.0, 0.0); + bool hitBlackHole = false; + bool hitObject = false; + Hit hit; + hit.objectColor = float4(0.0); + hit.hitCenter = float3(0.0); hit.hitRadius = 0.0; - float4 accumulatedColor = float4(0.0, 0.0, 0.0, 0.0); - float transmittance = 1.0; + bool hitDisk = false; + float3 diskColor = float3(0.0); // emission of the first (opaque) disk surface hit int maxSteps = cam.moving ? sim.maxStepsMoving : sim.maxStepsStatic; - if (maxSteps <= 0) maxSteps = cam.moving ? DEFAULT_MAX_STEPS_MOVING : DEFAULT_MAX_STEPS_STATIC; - float cameraDistance = length(cam.camPos); - if (cameraDistance > 2e12) - maxSteps = maxSteps / 2; - else if (cameraDistance > 1e12) - maxSteps = int(maxSteps * 0.75); - - float initialEscapeVelocity = sqrt(2.0 * SagA_rs / ray.r); - if (ray.dr > initialEscapeVelocity * 0.95 && - ray.r > SagA_rs * 200.0) - maxSteps = maxSteps / 2; - - float lambda = 0.0; - int objectCheckInterval = 5; + float exitDistance = sim.earlyExitDistance > 0.0 ? sim.earlyExitDistance : DEFAULT_EARLY_EXIT_DISTANCE; + int objectCheckInterval = 5; for (int i = 0; i < maxSteps; ++i) { - float exitDistance = sim.earlyExitDistance > 0.0 ? sim.earlyExitDistance : DEFAULT_EARLY_EXIT_DISTANCE; - if (ray.r > exitDistance) - break; - if (ray.r > ESCAPE_R) - break; - - if (Intercept(ray, SagA_rs)) - { - hitBlackHole = true; - break; - } - - float currentStepSize = CalculateAdaptiveStepSize(ray, D_LAMBDA); - - RK4Step(ray, currentStepSize); - lambda += currentStepSize; + if (Intercept(ray, SagA_rs)) { hitBlackHole = true; break; } + if (ray.r > exitDistance || ray.r > ESCAPE_R) break; + float3 prevPos = float3(ray.x, ray.y, ray.z); + float stepSize = CalculateAdaptiveStepSize(ray, D_LAMBDA); + RK4Step(ray, stepSize); float3 newPos = float3(ray.x, ray.y, ray.z); - if (IsInDiskVolume(newPos)) + // Opaque thin disk: a sign change in y means the ray pierced the disk + // plane (y = 0). The first crossing inside the annulus is a solid, + // self-luminous surface -- it emits and blocks everything behind it, so + // the ray stops here (near side occludes far side / background). + if (prevPos.y * newPos.y < 0.0) { - float4 diskSample = SampleDiskColor(newPos); - float density = diskSample.a; - float3 diskColor = diskSample.rgb; - - float stepLength = currentStepSize * 1e-8; - - float absorption = density * stepLength * 0.8; - float scattering = density * stepLength * 1.5; - float extinction = absorption + scattering; - - float stepTransmittance = exp(-extinction); - - float3 emission = diskColor * density * stepLength * 4.0 * sqrt(disk.disk_density); - - float3 glowColor = lerp(diskColor, float3(1.0, 0.8, 0.6), 0.3); - float glowIntensity = density * stepLength * 2.0; - float3 atmosphericGlow = glowColor * glowIntensity * 0.8; - - float3 totalEmission = emission + atmosphericGlow; - accumulatedColor.rgb += totalEmission * transmittance; - - transmittance *= stepTransmittance; - - if (transmittance < 0.01) + float t = prevPos.y / (prevPos.y - newPos.y); + float3 cross = lerp(prevPos, newPos, t); + float rc = length(float2(cross.x, cross.z)); + if (rc >= max(disk.disk_r1, R_ISCO) && rc <= disk.disk_r2) { - accumulatedColor.a = 1.0 - transmittance; + diskColor = DiskEmission(cross, newPos - prevPos); + hitDisk = true; break; } } - if (i % objectCheckInterval == 0 && InterceptObject(ray, hit)) - { - hitObject = true; - break; - } + if (i % objectCheckInterval == 0 && InterceptObject(ray, hit)) { hitObject = true; break; } - if (ray.dr > 0.0 && ray.r > SagA_rs * 100.0 && lambda > 2e8) - break; + // Principled escape: once outbound in near-flat spacetime (r >> r_s) the + // ray direction no longer changes, so stop and read the background. + if (ray.dr > 0.0 && ray.r > 50.0 * SagA_rs) break; } - accumulatedColor.a = 1.0 - transmittance; - - if (hitBlackHole) + float3 shade; + if (hitDisk) { - color = float4(0.0, 0.0, 0.0, 1.0); + shade = diskColor; // opaque, self-luminous disk surface + } + else if (hitBlackHole) + { + shade = float3(0.0); // event-horizon shadow } else if (hitObject) { float3 P = float3(ray.x, ray.y, ray.z); float3 N = normalize(P - hit.hitCenter); float3 V = normalize(cam.camPos - P); - - float ambient = 0.1; - float diff = max(dot(N, V), 0.0); - float intensity = ambient + (1.0 - ambient) * diff; - float3 shaded = hit.objectColor.rgb * intensity; - - color = float4(shaded, hit.objectColor.a); - color = lerp(accumulatedColor, color, color.a); + float intensity = 0.1 + 0.9 * max(dot(N, V), 0.0); + shade = hit.objectColor.rgb * intensity; } else { - float3 rayDirection = normalize(float3(ray.x, ray.y, ray.z) - cam.camPos); - float3 hdriColor = SampleHDRI(rayDirection); - color = float4(lerp(accumulatedColor.rgb, hdriColor, 1.0 - accumulatedColor.a), 1.0); + float3 rayDir = normalize(float3(ray.x, ray.y, ray.z) - cam.camPos); + shade = SampleHDRI(rayDir); } - return color; + return float4(ACESFilm(shade), 1.0); } diff --git a/src/platform/vulkan/vulkan_renderer.cpp b/src/platform/vulkan/vulkan_renderer.cpp index f2037dc..e19bee4 100644 --- a/src/platform/vulkan/vulkan_renderer.cpp +++ b/src/platform/vulkan/vulkan_renderer.cpp @@ -1,6 +1,7 @@ #include "vulkan_renderer.h" #include "core/log.h" #include "core/camera.h" +#include "core/settings_manager.h" #define GLFW_INCLUDE_VULKAN #include <GLFW/glfw3.h> @@ -82,20 +83,29 @@ namespace Donut VkPhysicalDeviceMemoryProperties mem_props{}; - // Geodesic scene, rendered every frame into a fixed low-resolution - // offscreen image (keeps each draw well under the Metal GPU watchdog), - // then upscaled onto the swapchain by the present pass below. - static constexpr uint32_t GEO_W = 480, GEO_H = 270; - VkImage geo_image = VK_NULL_HANDLE; - VkDeviceMemory geo_image_mem = VK_NULL_HANDLE; - VkImageView geo_image_view = VK_NULL_HANDLE; - VkRenderPass geo_render_pass = VK_NULL_HANDLE; - VkFramebuffer geo_framebuffer = VK_NULL_HANDLE; + // The geodesic is rendered every frame into an offscreen image, then + // upscaled onto the swapchain by the present pass. Progressive resolution: + // low-res while the camera moves (keeps dragging responsive and each draw + // well under the Metal GPU watchdog) and high-res once it settles (resolves + // the photon ring cleanly). Both are 16:9 so the camera aspect is shared. + static constexpr uint32_t GEO_LO_W = 480, GEO_LO_H = 270; + static constexpr uint32_t GEO_HI_W = 960, GEO_HI_H = 540; + struct GeoTarget + { + uint32_t w = 0, h = 0; + VkImage image = VK_NULL_HANDLE; + VkDeviceMemory mem = VK_NULL_HANDLE; + VkImageView view = VK_NULL_HANDLE; + VkFramebuffer fb = VK_NULL_HANDLE; + VkDescriptorSet present_set = VK_NULL_HANDLE; // present pass samples this target + }; + GeoTarget geo_lo, geo_hi; + VkRenderPass geo_render_pass = VK_NULL_HANDLE; // shared (resolution-independent) VkBuffer cam_buf = VK_NULL_HANDLE, disk_buf = VK_NULL_HANDLE, obj_buf = VK_NULL_HANDLE, sim_buf = VK_NULL_HANDLE; VkDeviceMemory cam_mem = VK_NULL_HANDLE, disk_mem = VK_NULL_HANDLE, obj_mem = VK_NULL_HANDLE, sim_mem = VK_NULL_HANDLE; void* cam_mapped = nullptr; void* sim_mapped = nullptr; - Camera camera{ 60.0f, (float)GEO_W / (float)GEO_H, 0.1f, 100.0f }; + Camera camera{ 60.0f, (float)GEO_HI_W / (float)GEO_HI_H, 0.1f, 100.0f }; bool left_was_down = false; double last_frame_time = 0.0; // for free-fly dt double fps_last_x = 0.0, fps_last_y = 0.0; // cursor tracking for free-fly look @@ -117,14 +127,13 @@ namespace Donut VkSampler present_sampler = VK_NULL_HANDLE; VkDescriptorSetLayout present_set_layout = VK_NULL_HANDLE; VkDescriptorPool present_pool = VK_NULL_HANDLE; - VkDescriptorSet present_set = VK_NULL_HANDLE; VkPipelineLayout present_pipeline_layout = VK_NULL_HANDLE; VkPipeline present_pipeline = VK_NULL_HANDLE; // World-builder scene view (grid now; sphere/skybox next). Normal-scale // orbital camera; geometry drawn straight into the swapchain render pass. bool scene_mode = false; - Camera scene_camera{ 45.0f, (float)GEO_W / (float)GEO_H, 0.1f, 1000.0f }; + Camera scene_camera{ 45.0f, (float)GEO_HI_W / (float)GEO_HI_H, 0.1f, 1000.0f }; VkBuffer grid_vb = VK_NULL_HANDLE; VkDeviceMemory grid_vb_mem = VK_NULL_HANDLE; uint32_t grid_vertex_count = 0; VkBuffer grid_ubo = VK_NULL_HANDLE; VkDeviceMemory grid_ubo_mem = VK_NULL_HANDLE; @@ -184,6 +193,7 @@ namespace Donut auto create_command_buffers() -> bool; auto create_sync_objects() -> bool; auto create_geodesic_resources() -> bool; + auto create_geo_target(GeoTarget& target, uint32_t w, uint32_t h) -> bool; auto create_hdri_cubemap(const char* path) -> bool; auto rebuild_hdri_cubemap(const char* path) -> void; auto create_present_resources() -> bool; @@ -584,28 +594,42 @@ namespace Donut return vkCreateShaderModule(device, &ci, nullptr, &out) == VK_SUCCESS; } - auto VulkanRenderer::Impl::create_geodesic_resources() -> bool + // Creates one geodesic render target (image + memory + view + framebuffer) + // at w x h against the shared geo_render_pass. Used for the low- and high-res + // progressive targets. + auto VulkanRenderer::Impl::create_geo_target(GeoTarget& t, uint32_t w, uint32_t h) -> bool { const VkFormat fmt = VK_FORMAT_R8G8B8A8_UNORM; - const VkMemoryPropertyFlags host_vis = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT; - const float SagA_rs = 1.269e10f; + t.w = w; t.h = h; VkImageCreateInfo ici{ VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO }; - ici.imageType = VK_IMAGE_TYPE_2D; ici.format = fmt; ici.extent = { GEO_W, GEO_H, 1 }; + ici.imageType = VK_IMAGE_TYPE_2D; ici.format = fmt; ici.extent = { w, h, 1 }; ici.mipLevels = 1; ici.arrayLayers = 1; ici.samples = VK_SAMPLE_COUNT_1_BIT; ici.tiling = VK_IMAGE_TILING_OPTIMAL; ici.usage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | VK_IMAGE_USAGE_SAMPLED_BIT; - VK_CHECK(vkCreateImage(device, &ici, nullptr, &geo_image)); - VkMemoryRequirements im_req{}; vkGetImageMemoryRequirements(device, geo_image, &im_req); + VK_CHECK(vkCreateImage(device, &ici, nullptr, &t.image)); + VkMemoryRequirements im_req{}; vkGetImageMemoryRequirements(device, t.image, &im_req); VkMemoryAllocateInfo im_alloc{ VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO }; im_alloc.allocationSize = im_req.size; im_alloc.memoryTypeIndex = find_memory_type(im_req.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT); - VK_CHECK(vkAllocateMemory(device, &im_alloc, nullptr, &geo_image_mem)); - VK_CHECK(vkBindImageMemory(device, geo_image, geo_image_mem, 0)); + VK_CHECK(vkAllocateMemory(device, &im_alloc, nullptr, &t.mem)); + VK_CHECK(vkBindImageMemory(device, t.image, t.mem, 0)); VkImageViewCreateInfo vci{ VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO }; - vci.image = geo_image; vci.viewType = VK_IMAGE_VIEW_TYPE_2D; vci.format = fmt; + vci.image = t.image; vci.viewType = VK_IMAGE_VIEW_TYPE_2D; vci.format = fmt; vci.subresourceRange = { VK_IMAGE_ASPECT_COLOR_BIT, 0, 1, 0, 1 }; - VK_CHECK(vkCreateImageView(device, &vci, nullptr, &geo_image_view)); + VK_CHECK(vkCreateImageView(device, &vci, nullptr, &t.view)); + VkFramebufferCreateInfo fbci{ VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO }; + fbci.renderPass = geo_render_pass; fbci.attachmentCount = 1; fbci.pAttachments = &t.view; + fbci.width = w; fbci.height = h; fbci.layers = 1; + VK_CHECK(vkCreateFramebuffer(device, &fbci, nullptr, &t.fb)); + return true; + } + + auto VulkanRenderer::Impl::create_geodesic_resources() -> bool + { + const VkFormat fmt = VK_FORMAT_R8G8B8A8_UNORM; + const VkMemoryPropertyFlags host_vis = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT; + const float SagA_rs = 1.269e10f; VkAttachmentDescription color{}; color.format = fmt; color.samples = VK_SAMPLE_COUNT_1_BIT; @@ -627,10 +651,9 @@ namespace Donut rpci.subpassCount = 1; rpci.pSubpasses = &subpass; rpci.dependencyCount = 2; rpci.pDependencies = deps; VK_CHECK(vkCreateRenderPass(device, &rpci, nullptr, &geo_render_pass)); - VkFramebufferCreateInfo fbci{ VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO }; - fbci.renderPass = geo_render_pass; fbci.attachmentCount = 1; fbci.pAttachments = &geo_image_view; - fbci.width = GEO_W; fbci.height = GEO_H; fbci.layers = 1; - VK_CHECK(vkCreateFramebuffer(device, &fbci, nullptr, &geo_framebuffer)); + + if (!create_geo_target(geo_lo, GEO_LO_W, GEO_LO_H)) return false; + if (!create_geo_target(geo_hi, GEO_HI_W, GEO_HI_H)) return false; create_buffer(128, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, host_vis, cam_buf, cam_mem); create_buffer(32, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, host_vis, disk_buf, disk_mem); @@ -639,17 +662,19 @@ namespace Donut camera.set_camera_mode(CameraMode::Orbital); camera.set_orbital_target(glm::vec3(0.0f)); - camera.set_orbital_radius(1e11); - camera.set_orbital_limits(4e10, 3e11); + camera.set_orbital_radius(4e11); // ~31 r_s: outside the 12 r_s disk + camera.set_orbital_limits(2.2e11, 1.5e12); camera.set_orbital_speed(0.01f); - camera.set_zoom_speed(1e10); + camera.set_zoom_speed(3e10); camera.set_azimuth(0.0f); camera.set_elevation(1.25f); void* p = nullptr; vkMapMemory(device, cam_mem, 0, 128, 0, &cam_mapped); // camera UBO is refilled every frame - float disk_data[8] = { SagA_rs * 2.2f, SagA_rs * 5.2f, 2.0f, SagA_rs * 0.1f, 0.1f, 0, 0, 0 }; + // disk_r1=inner (ISCO 3 r_s), disk_r2=outer, disk_num=turbulence strength, + // thickness (unused by the thin-disk model), disk_density=exposure. + float disk_data[8] = { SagA_rs * 3.0f, SagA_rs * 12.0f, 0.4f, SagA_rs * 0.1f, 0.1f, 0, 0, 0 }; vkMapMemory(device, disk_mem, 0, 32, 0, &p); memcpy(p, disk_data, sizeof(disk_data)); vkUnmapMemory(device, disk_mem); std::vector<uint8_t> obj_data(800, 0); @@ -704,8 +729,11 @@ namespace Donut vin.vertexBindingDescriptionCount = 1; vin.pVertexBindingDescriptions = &vib; vin.vertexAttributeDescriptionCount = 2; vin.pVertexAttributeDescriptions = via; VkPipelineInputAssemblyStateCreateInfo ia{ VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO }; ia.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST; - VkViewport vp{ 0, 0, (float)GEO_W, (float)GEO_H, 0, 1 }; VkRect2D sc{ { 0, 0 }, { GEO_W, GEO_H } }; - VkPipelineViewportStateCreateInfo vps{ VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO }; vps.viewportCount = 1; vps.pViewports = &vp; vps.scissorCount = 1; vps.pScissors = ≻ + // Dynamic viewport/scissor: the same pipeline renders into either the + // low- or high-res target, sized per frame in record_command_buffer. + VkPipelineViewportStateCreateInfo vps{ VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO }; vps.viewportCount = 1; vps.scissorCount = 1; + VkDynamicState dyn_states[2] = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR }; + VkPipelineDynamicStateCreateInfo dyn{ VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO }; dyn.dynamicStateCount = 2; dyn.pDynamicStates = dyn_states; VkPipelineRasterizationStateCreateInfo rs{ VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO }; rs.polygonMode = VK_POLYGON_MODE_FILL; rs.cullMode = VK_CULL_MODE_NONE; rs.frontFace = VK_FRONT_FACE_COUNTER_CLOCKWISE; rs.lineWidth = 1.0f; VkPipelineMultisampleStateCreateInfo ms{ VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO }; ms.rasterizationSamples = VK_SAMPLE_COUNT_1_BIT; VkPipelineColorBlendAttachmentState cba{}; cba.colorWriteMask = VK_COLOR_COMPONENT_R_BIT | VK_COLOR_COMPONENT_G_BIT | VK_COLOR_COMPONENT_B_BIT | VK_COLOR_COMPONENT_A_BIT; @@ -714,6 +742,7 @@ namespace Donut gpci.stageCount = 2; gpci.pStages = stages; gpci.pVertexInputState = &vin; gpci.pInputAssemblyState = &ia; gpci.pViewportState = &vps; gpci.pRasterizationState = &rs; gpci.pMultisampleState = &ms; gpci.pColorBlendState = &cb; + gpci.pDynamicState = &dyn; gpci.layout = geo_pipeline_layout; gpci.renderPass = geo_render_pass; gpci.subpass = 0; VkResult pr = vkCreateGraphicsPipelines(device, VK_NULL_HANDLE, 1, &gpci, nullptr, &geo_pipeline); vkDestroyShaderModule(device, vmod, nullptr); vkDestroyShaderModule(device, fmod, nullptr); @@ -721,7 +750,8 @@ namespace Donut start_time = glfwGetTime(); update_geodesic_uniforms(); - DONUT_INFO("Vulkan: geodesic resources ready ({}x{} offscreen)", (int)GEO_W, (int)GEO_H); + DONUT_INFO("Vulkan: geodesic resources ready ({}x{} moving / {}x{} settled)", + (int)GEO_LO_W, (int)GEO_LO_H, (int)GEO_HI_W, (int)GEO_HI_H); return true; } @@ -1021,17 +1051,22 @@ namespace Donut VkDescriptorSetLayoutCreateInfo dslci{ VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO }; dslci.bindingCount = 1; dslci.pBindings = &bind; VK_CHECK(vkCreateDescriptorSetLayout(device, &dslci, nullptr, &present_set_layout)); - VkDescriptorPoolSize psize{ VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1 }; + // One present set per geodesic target (low-/high-res), each sampling its + // own image; record_command_buffer binds whichever was rendered this frame. + VkDescriptorPoolSize psize{ VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 2 }; VkDescriptorPoolCreateInfo dpci{ VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO }; - dpci.maxSets = 1; dpci.poolSizeCount = 1; dpci.pPoolSizes = &psize; + dpci.maxSets = 2; dpci.poolSizeCount = 1; dpci.pPoolSizes = &psize; VK_CHECK(vkCreateDescriptorPool(device, &dpci, nullptr, &present_pool)); - VkDescriptorSetAllocateInfo dsai{ VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO }; - dsai.descriptorPool = present_pool; dsai.descriptorSetCount = 1; dsai.pSetLayouts = &present_set_layout; - VK_CHECK(vkAllocateDescriptorSets(device, &dsai, &present_set)); - VkDescriptorImageInfo ii{ present_sampler, geo_image_view, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL }; - VkWriteDescriptorSet write{ VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET }; - write.dstSet = present_set; write.dstBinding = 0; write.descriptorCount = 1; write.descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER; write.pImageInfo = ⅈ - vkUpdateDescriptorSets(device, 1, &write, 0, nullptr); + for (GeoTarget* t : { &geo_lo, &geo_hi }) + { + VkDescriptorSetAllocateInfo dsai{ VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO }; + dsai.descriptorPool = present_pool; dsai.descriptorSetCount = 1; dsai.pSetLayouts = &present_set_layout; + VK_CHECK(vkAllocateDescriptorSets(device, &dsai, &t->present_set)); + VkDescriptorImageInfo ii{ present_sampler, t->view, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL }; + VkWriteDescriptorSet write{ VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET }; + write.dstSet = t->present_set; write.dstBinding = 0; write.descriptorCount = 1; write.descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER; write.pImageInfo = ⅈ + vkUpdateDescriptorSets(device, 1, &write, 0, nullptr); + } VkShaderModule vmod, fmod; if (!create_shader_module("assets/shaders/generated/TexturedQuad.vertexMain.spv", vmod)) return false; @@ -1399,14 +1434,24 @@ namespace Donut glm::vec3 right = glm::normalize(glm::cross(fwd, glm::vec3(0, 1, 0))); cam_data.pos = pos; cam_data.right = right; cam_data.up = glm::cross(right, fwd); cam_data.fwd = fwd; cam_data.tan_half_fov = (float)tan(glm::radians(60.0f * 0.5f)); - cam_data.aspect = (float)GEO_W / (float)GEO_H; + cam_data.aspect = (float)GEO_HI_W / (float)GEO_HI_H; // 16:9, same for both targets cam_data.moving = user_moving ? 1u : 0u; if (cam_mapped) memcpy(cam_mapped, &cam_data, sizeof(cam_data)); - // Fewer integration steps while the camera moves keeps dragging responsive; - // more steps once it settles renders the disk in full. + // Integration budget drives how deep the geodesics are traced: too few + // steps and grazing rays exhaust the loop mid-lensing, so the shader + // paints them with the HDRI (Geodesic.slang) and the hole looks sliced + // off "up to a certain depth" -- and near face-on it vanishes entirely. + // Measured: at ~8000 steps the disk disappears at steep poses, ~15000 is + // needed for it to resolve, INDEPENDENT of resolution. So we DON'T drop + // steps while moving (that would make the hole flicker out mid-drag); + // responsiveness comes from the lower-res target instead (see record). + // Sourced from settings.toml (max_steps_static), capped GPU-safe. + constexpr int kStepCeil = 15000; struct SimUBO { int steps_moving; int steps_static; float early_exit; float time; } sim; - sim.steps_moving = 3500; sim.steps_static = 5000; sim.early_exit = 5e12f; + sim.steps_static = std::clamp(SettingsManager::get_max_steps_static(), 1000, kStepCeil); + sim.steps_moving = sim.steps_static; // same budget both frames; resolution is the lever + sim.early_exit = SettingsManager::get_early_exit_distance(); sim.time = (float)(glfwGetTime() - start_time); if (sim_mapped) memcpy(sim_mapped, &sim, sizeof(sim)); } @@ -1529,11 +1574,14 @@ namespace Donut VkBuffer ubos[4] = { cam_buf, disk_buf, obj_buf, sim_buf }; VkDeviceMemory umem[4] = { cam_mem, disk_mem, obj_mem, sim_mem }; for (int i = 0; i < 4; ++i) { if (ubos[i]) vkDestroyBuffer(device, ubos[i], nullptr); if (umem[i]) vkFreeMemory(device, umem[i], nullptr); } - if (geo_framebuffer) vkDestroyFramebuffer(device, geo_framebuffer, nullptr); + for (GeoTarget* t : { &geo_lo, &geo_hi }) + { + if (t->fb) vkDestroyFramebuffer(device, t->fb, nullptr); + if (t->view) vkDestroyImageView(device, t->view, nullptr); + if (t->image) vkDestroyImage(device, t->image, nullptr); + if (t->mem) vkFreeMemory(device, t->mem, nullptr); + } if (geo_render_pass) vkDestroyRenderPass(device, geo_render_pass, nullptr); - if (geo_image_view) vkDestroyImageView(device, geo_image_view, nullptr); - if (geo_image) vkDestroyImage(device, geo_image, nullptr); - if (geo_image_mem) vkFreeMemory(device, geo_image_mem, nullptr); } auto VulkanRenderer::Impl::record_command_buffer(VkCommandBuffer cmd, uint32_t image_index, const glm::vec4& clear, ImDrawData* draw_data) -> bool @@ -1589,14 +1637,20 @@ namespace Donut return true; } - // Geodesic offscreen pass + // Geodesic offscreen pass. Progressive resolution: low-res while the + // camera moves (4x fewer pixels -> responsive), high-res once it settles + // (resolves the photon ring). Step count is the same for both (the disk + // vanishes below ~15000 steps at steep poses), so resolution is the lever. + GeoTarget& gt = user_moving ? geo_lo : geo_hi; VkClearValue geo_clear{}; geo_clear.color = { { 0, 0, 0, 1 } }; VkRenderPassBeginInfo grp{ VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO }; - grp.renderPass = geo_render_pass; grp.framebuffer = geo_framebuffer; - grp.renderArea = { { 0, 0 }, { GEO_W, GEO_H } }; + grp.renderPass = geo_render_pass; grp.framebuffer = gt.fb; + grp.renderArea = { { 0, 0 }, { gt.w, gt.h } }; grp.clearValueCount = 1; grp.pClearValues = &geo_clear; vkCmdBeginRenderPass(cmd, &grp, VK_SUBPASS_CONTENTS_INLINE); vkCmdBindPipeline(cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, geo_pipeline); + VkViewport gvp{ 0, 0, (float)gt.w, (float)gt.h, 0, 1 }; VkRect2D gsc{ { 0, 0 }, { gt.w, gt.h } }; + vkCmdSetViewport(cmd, 0, 1, &gvp); vkCmdSetScissor(cmd, 0, 1, &gsc); vkCmdBindDescriptorSets(cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, geo_pipeline_layout, 0, 1, &geo_set, 0, nullptr); VkDeviceSize off = 0; vkCmdBindVertexBuffers(cmd, 0, 1, &quad_vb, &off); vkCmdDraw(cmd, 6, 1, 0, 0); @@ -1618,7 +1672,7 @@ namespace Donut VkRect2D scissor{ { 0, 0 }, swapchain_extent }; vkCmdSetViewport(cmd, 0, 1, &vp); vkCmdSetScissor(cmd, 0, 1, &scissor); - vkCmdBindDescriptorSets(cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, present_pipeline_layout, 0, 1, &present_set, 0, nullptr); + vkCmdBindDescriptorSets(cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, present_pipeline_layout, 0, 1, >.present_set, 0, nullptr); vkCmdBindVertexBuffers(cmd, 0, 1, &quad_vb, &off); vkCmdDraw(cmd, 6, 1, 0, 0); if (draw_data) |