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Diffstat (limited to '3rdparty/bgfx/examples/44-sss/screen_space_shadows.cpp')
-rw-r--r-- | 3rdparty/bgfx/examples/44-sss/screen_space_shadows.cpp | 849 |
1 files changed, 849 insertions, 0 deletions
diff --git a/3rdparty/bgfx/examples/44-sss/screen_space_shadows.cpp b/3rdparty/bgfx/examples/44-sss/screen_space_shadows.cpp new file mode 100644 index 00000000000..1bf85b0e973 --- /dev/null +++ b/3rdparty/bgfx/examples/44-sss/screen_space_shadows.cpp @@ -0,0 +1,849 @@ +/* +* Copyright 2021 elven cache. All rights reserved. +* License: https://github.com/bkaradzic/bgfx/blob/master/LICENSE +*/ + +/* +* Implement screen space shadows as bgfx example. Goal is to explore various +* options and parameters. +* +* radius +* ====== +* Use radius/shadow distance defined in screen space pixels or world units. +* +* In world uints, the screen distance will shrink as objects get farther away. +* This can provide more natural looking shadows and fade out the effect at a +* distance, leaving screen space shadows as an added detail effect near the +* camera. +* +* Screen space units mean that objects will cast the same length of shadow +* regardless of how far they are away from the camera. Pull back the camera +* and objects' shadows will appear to grow. On the other hand, this can be +* desired because it will allow objects at the horizon like hills and trees to +* cast a shadow. Depending on your scene, such far objects may be outside of +* the area affected by regular shadow maps. Even with multiple cascades, you +* may not be able to afford shadow maps across the entire scene. +* +* This sample does not put effort into avoiding the initial pixel or avoiding +* resampling the same value if the step size is relatively smaller than the +* sampled distance in screen space. May want to set a minimum distance so each +* sample covers a unique value or take care to select a neighboring pixel for +* the first sample. +* +* soft contact shadows +* ==================== +* If hard screen space shadows are added to a scene that already has soft +* shadows via shadow maps, the hard edge can look out of place. Additionally, +* it is common for screen space shadows to not quite line up with other +* shadows. This is because the depth buffer does not specify thickness, +* leaving some pixels incorrectly occluded. For example, you would not want +* some thin feature like a pipe to cast a shadow as if you were seeing the +* side of a metal wall. +* +* These soft contact shadows are an attempt to minimize the problems described +* above. By adding a smoother falloff, they may blend into the scene better. +* Inspired by screen space ambient occlusion, this sample takes into account +* distance from shadowed pixel to its occluders. +* +* - hard If there's any occluder found, mark the source pixel as shadowed. +* +* - soft Modulate shadow by distance to the first occluder. Assuming a +* nearby pixel is closer and more likely to represent an accurate +* shadow, it is darker. If the first pixel to be an occluder is far +* away, it should likely cast a softer shadow. +* +* - very In addition to the same modulation used by soft mode, also +* soft reduce the occlusion contribution from pixels that are farther +* away. This sample compares the depth difference to the shadow +* radius, a 1D distance, instead of comparing the actually +* distance in 3D space. +*/ + + +#include <common.h> +#include <camera.h> +#include <bgfx_utils.h> +#include <imgui/imgui.h> +#include <bx/rng.h> +#include <bx/os.h> + + +namespace { + +// Gbuffer has multiple render targets +#define GBUFFER_RT_COLOR 0 +#define GBUFFER_RT_NORMAL 1 +#define GBUFFER_RT_DEPTH 2 +#define GBUFFER_RENDER_TARGETS 3 + +#define MODEL_COUNT 100 + +static const char * s_meshPaths[] = +{ + "meshes/unit_sphere.bin", + "meshes/column.bin", + "meshes/tree.bin", + "meshes/hollowcube.bin", + "meshes/bunny.bin" +}; + +static const float s_meshScale[] = +{ + 0.25f, + 0.05f, + 0.15f, + 0.25f, + 0.25f +}; + +// Vertex decl for our screen space quad (used in deferred rendering) +struct PosTexCoord0Vertex +{ + float m_x; + float m_y; + float m_z; + float m_u; + float m_v; + + static void init() + { + ms_layout + .begin() + .add(bgfx::Attrib::Position, 3, bgfx::AttribType::Float) + .add(bgfx::Attrib::TexCoord0, 2, bgfx::AttribType::Float) + .end(); + } + + static bgfx::VertexLayout ms_layout; +}; + +bgfx::VertexLayout PosTexCoord0Vertex::ms_layout; + +struct Uniforms +{ + enum { NumVec4 = 12 }; + + void init() { + u_params = bgfx::createUniform("u_params", bgfx::UniformType::Vec4, NumVec4); + }; + + void submit() const { + bgfx::setUniform(u_params, m_params, NumVec4); + } + + void destroy() { + bgfx::destroy(u_params); + } + + union + { + struct + { + /* 0 */ struct { float m_frameIdx; float m_shadowRadius; float m_shadowSteps; float m_useNoiseOffset; }; + /* 1 */ struct { float m_depthUnpackConsts[2]; float m_contactShadowsMode; float m_useScreenSpaceRadius; }; + /* 2 */ struct { float m_ndcToViewMul[2]; float m_ndcToViewAdd[2]; }; + /* 3 */ struct { float m_lightPosition[3]; float m_displayShadows; }; + /* 4-7 */ struct { float m_worldToView[16]; }; // built-in u_view will be transform for quad during screen passes + /* 8-11 */ struct { float m_viewToProj[16]; }; // built-in u_proj will be transform for quad during screen passes + }; + + float m_params[NumVec4 * 4]; + }; + + bgfx::UniformHandle u_params; +}; + +struct RenderTarget +{ + void init(uint32_t _width, uint32_t _height, bgfx::TextureFormat::Enum _format, uint64_t _flags) + { + m_texture = bgfx::createTexture2D(uint16_t(_width), uint16_t(_height), false, 1, _format, _flags); + const bool destroyTextures = true; + m_buffer = bgfx::createFrameBuffer(1, &m_texture, destroyTextures); + } + + void destroy() + { + // also responsible for destroying texture + bgfx::destroy(m_buffer); + } + + bgfx::TextureHandle m_texture; + bgfx::FrameBufferHandle m_buffer; +}; + +void screenSpaceQuad(float _textureWidth, float _textureHeight, float _texelHalf, bool _originBottomLeft, float _width = 1.0f, float _height = 1.0f) +{ + if (3 == bgfx::getAvailTransientVertexBuffer(3, PosTexCoord0Vertex::ms_layout)) + { + bgfx::TransientVertexBuffer vb; + bgfx::allocTransientVertexBuffer(&vb, 3, PosTexCoord0Vertex::ms_layout); + PosTexCoord0Vertex* vertex = (PosTexCoord0Vertex*)vb.data; + + const float minx = -_width; + const float maxx = _width; + const float miny = 0.0f; + const float maxy = _height * 2.0f; + + const float texelHalfW = _texelHalf / _textureWidth; + const float texelHalfH = _texelHalf / _textureHeight; + const float minu = -1.0f + texelHalfW; + const float maxu = 1.0f + texelHalfW; + + const float zz = 0.0f; + + float minv = texelHalfH; + float maxv = 2.0f + texelHalfH; + + if (_originBottomLeft) + { + float temp = minv; + minv = maxv; + maxv = temp; + + minv -= 1.0f; + maxv -= 1.0f; + } + + vertex[0].m_x = minx; + vertex[0].m_y = miny; + vertex[0].m_z = zz; + vertex[0].m_u = minu; + vertex[0].m_v = minv; + + vertex[1].m_x = maxx; + vertex[1].m_y = miny; + vertex[1].m_z = zz; + vertex[1].m_u = maxu; + vertex[1].m_v = minv; + + vertex[2].m_x = maxx; + vertex[2].m_y = maxy; + vertex[2].m_z = zz; + vertex[2].m_u = maxu; + vertex[2].m_v = maxv; + + bgfx::setVertexBuffer(0, &vb); + } +} + +void vec2Set(float* _v, float _x, float _y) +{ + _v[0] = _x; + _v[1] = _y; +} + +void mat4Set(float * _m, const float * _src) +{ + const uint32_t MAT4_FLOATS = 16; + for (uint32_t ii = 0; ii < MAT4_FLOATS; ++ii) { + _m[ii] = _src[ii]; + } +} + +class ExampleScreenSpaceShadows : public entry::AppI +{ +public: + ExampleScreenSpaceShadows(const char* _name, const char* _description) + : entry::AppI(_name, _description) + , m_currFrame(UINT32_MAX) + , m_texelHalf(0.0f) + { + } + + void init(int32_t _argc, const char* const* _argv, uint32_t _width, uint32_t _height) override + { + Args args(_argc, _argv); + + m_width = _width; + m_height = _height; + m_debug = BGFX_DEBUG_NONE; + m_reset = BGFX_RESET_VSYNC; + + bgfx::Init init; + init.type = args.m_type; + init.vendorId = args.m_pciId; + init.platformData.nwh = entry::getNativeWindowHandle(entry::kDefaultWindowHandle); + init.platformData.ndt = entry::getNativeDisplayHandle(); + init.platformData.type = entry::getNativeWindowHandleType(entry::kDefaultWindowHandle); + init.resolution.width = m_width; + init.resolution.height = m_height; + init.resolution.reset = m_reset; + bgfx::init(init); + + // Enable debug text. + bgfx::setDebug(m_debug); + + // Create uniforms + m_uniforms.init(); + + // Create texture sampler uniforms (used when we bind textures) + s_albedo = bgfx::createUniform("s_albedo", bgfx::UniformType::Sampler); // Model's source albedo + s_color = bgfx::createUniform("s_color", bgfx::UniformType::Sampler); // Color (albedo) gbuffer, default color input + s_normal = bgfx::createUniform("s_normal", bgfx::UniformType::Sampler); // Normal gbuffer, Model's source normal + s_depth = bgfx::createUniform("s_depth", bgfx::UniformType::Sampler); // Depth gbuffer + s_shadows = bgfx::createUniform("s_shadows", bgfx::UniformType::Sampler); + + // Create program from shaders. + m_gbufferProgram = loadProgram("vs_sss_gbuffer", "fs_sss_gbuffer"); // Fill gbuffer + m_sphereProgram = loadProgram("vs_sss_gbuffer", "fs_sss_unlit"); + m_linearDepthProgram = loadProgram("vs_sss_screenquad", "fs_sss_linear_depth"); + m_shadowsProgram = loadProgram("vs_sss_screenquad", "fs_screen_space_shadows"); + m_combineProgram = loadProgram("vs_sss_screenquad", "fs_sss_deferred_combine"); // Compute lighting from gbuffer + + // Load some meshes + for (uint32_t ii = 0; ii < BX_COUNTOF(s_meshPaths); ++ii) + { + m_meshes[ii] = meshLoad(s_meshPaths[ii]); + } + + // sphere is first mesh + m_lightModel.mesh = 0; + + // Randomly create some models + bx::RngMwc mwc; + for (uint32_t ii = 0; ii < BX_COUNTOF(m_models); ++ii) + { + Model& model = m_models[ii]; + + model.mesh = mwc.gen() % BX_COUNTOF(s_meshPaths); + model.position[0] = (((mwc.gen() % 256)) - 128.0f) / 20.0f; + model.position[1] = 0; + model.position[2] = (((mwc.gen() % 256)) - 128.0f) / 20.0f; + } + + // Load ground, just use the cube + m_ground = meshLoad("meshes/cube.bin"); + + m_groundTexture = loadTexture("textures/fieldstone-rgba.dds"); + m_normalTexture = loadTexture("textures/fieldstone-n.dds"); + + m_recreateFrameBuffers = false; + createFramebuffers(); + + // Vertex decl + PosTexCoord0Vertex::init(); + + // Init camera + cameraCreate(); + cameraSetPosition({ 0.0f, 1.5f, -4.0f }); + cameraSetVerticalAngle(-0.3f); + m_fovY = 60.0f; + + cameraGetViewMtx(m_view); + bx::mtxProj(m_proj, m_fovY, float(m_size[0]) / float(m_size[1]), 0.01f, 100.0f, bgfx::getCaps()->homogeneousDepth); + + // Track whether previous results are valid + m_havePrevious = false; + + // Get renderer capabilities info. + const bgfx::RendererType::Enum renderer = bgfx::getRendererType(); + m_texelHalf = bgfx::RendererType::Direct3D9 == renderer ? 0.5f : 0.0f; + + imguiCreate(); + } + + int32_t shutdown() override + { + for (uint32_t ii = 0; ii < BX_COUNTOF(s_meshPaths); ++ii) + { + meshUnload(m_meshes[ii]); + } + meshUnload(m_ground); + + bgfx::destroy(m_normalTexture); + bgfx::destroy(m_groundTexture); + + bgfx::destroy(m_gbufferProgram); + bgfx::destroy(m_sphereProgram); + bgfx::destroy(m_linearDepthProgram); + bgfx::destroy(m_shadowsProgram); + bgfx::destroy(m_combineProgram); + + m_uniforms.destroy(); + + bgfx::destroy(s_albedo); + bgfx::destroy(s_color); + bgfx::destroy(s_normal); + bgfx::destroy(s_depth); + bgfx::destroy(s_shadows); + + destroyFramebuffers(); + + cameraDestroy(); + + imguiDestroy(); + + bgfx::shutdown(); + + return 0; + } + + bool update() override + { + if (!entry::processEvents(m_width, m_height, m_debug, m_reset, &m_mouseState)) + { + // skip processing when minimized, otherwise crashing + if (0 == m_width + || 0 == m_height) + { + return true; + } + + // Update frame timer + int64_t now = bx::getHPCounter(); + static int64_t last = now; + const int64_t frameTime = now - last; + last = now; + const double freq = double(bx::getHPFrequency()); + const float deltaTime = float(frameTime / freq); + const bgfx::Caps* caps = bgfx::getCaps(); + + if (m_size[0] != (int32_t)m_width + || m_size[1] != (int32_t)m_height + || m_recreateFrameBuffers) + { + destroyFramebuffers(); + createFramebuffers(); + m_recreateFrameBuffers = false; + } + + // rotate light + const float rotationSpeed = m_moveLight ? 0.75f : 0.0f; + m_lightRotation += deltaTime * rotationSpeed; + if (bx::kPi2 < m_lightRotation) + { + m_lightRotation -= bx::kPi2; + } + m_lightModel.position[0] = bx::cos(m_lightRotation) * 3.0f; + m_lightModel.position[1] = 1.5f; + m_lightModel.position[2] = bx::sin(m_lightRotation) * 3.0f; + + // Update camera + cameraUpdate(deltaTime*0.15f, m_mouseState, ImGui::MouseOverArea() ); + + // Set up matrices for gbuffer + cameraGetViewMtx(m_view); + + updateUniforms(); + + bx::mtxProj(m_proj, m_fovY, float(m_size[0]) / float(m_size[1]), 0.01f, 100.0f, caps->homogeneousDepth); + bx::mtxProj(m_proj2, m_fovY, float(m_size[0]) / float(m_size[1]), 0.01f, 100.0f, false); + + bgfx::ViewId view = 0; + + // Draw everything into gbuffer + { + bgfx::setViewName(view, "gbuffer"); + bgfx::setViewClear(view + , BGFX_CLEAR_COLOR | BGFX_CLEAR_DEPTH + , 0 + , 1.0f + , 0 + ); + + bgfx::setViewRect(view, 0, 0, uint16_t(m_size[0]), uint16_t(m_size[1])); + bgfx::setViewTransform(view, m_view, m_proj); + // Make sure when we draw it goes into gbuffer and not backbuffer + bgfx::setViewFrameBuffer(view, m_gbuffer); + + bgfx::setState(0 + | BGFX_STATE_WRITE_RGB + | BGFX_STATE_WRITE_A + | BGFX_STATE_WRITE_Z + | BGFX_STATE_DEPTH_TEST_LESS + ); + + drawAllModels(view, m_gbufferProgram, m_uniforms); + + // draw sphere to visualize light + { + const float scale = s_meshScale[m_lightModel.mesh]; + float mtx[16]; + bx::mtxSRT(mtx + , scale + , scale + , scale + , 0.0f + , 0.0f + , 0.0f + , m_lightModel.position[0] + , m_lightModel.position[1] + , m_lightModel.position[2] + ); + + m_uniforms.submit(); + meshSubmit(m_meshes[m_lightModel.mesh], view, m_sphereProgram, mtx); + } + + ++view; + } + + float orthoProj[16]; + bx::mtxOrtho(orthoProj, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, caps->homogeneousDepth); + { + // clear out transform stack + float identity[16]; + bx::mtxIdentity(identity); + bgfx::setTransform(identity); + } + + // Convert depth to linear depth for shadow depth compare + { + bgfx::setViewName(view, "linear depth"); + + bgfx::setViewRect(view, 0, 0, uint16_t(m_width), uint16_t(m_height)); + bgfx::setViewTransform(view, NULL, orthoProj); + bgfx::setViewFrameBuffer(view, m_linearDepth.m_buffer); + bgfx::setState(0 + | BGFX_STATE_WRITE_RGB + | BGFX_STATE_WRITE_A + | BGFX_STATE_DEPTH_TEST_ALWAYS + ); + bgfx::setTexture(0, s_depth, m_gbufferTex[GBUFFER_RT_DEPTH]); + m_uniforms.submit(); + screenSpaceQuad(float(m_width), float(m_height), m_texelHalf, caps->originBottomLeft); + bgfx::submit(view, m_linearDepthProgram); + ++view; + } + + // Do screen space shadows + { + bgfx::setViewName(view, "screen space shadows"); + + bgfx::setViewRect(view, 0, 0, uint16_t(m_width), uint16_t(m_height)); + bgfx::setViewTransform(view, NULL, orthoProj); + bgfx::setViewFrameBuffer(view, m_shadows.m_buffer); + bgfx::setState(0 + | BGFX_STATE_WRITE_RGB + | BGFX_STATE_WRITE_A + | BGFX_STATE_DEPTH_TEST_ALWAYS + ); + bgfx::setTexture(0, s_depth, m_linearDepth.m_texture); + m_uniforms.submit(); + screenSpaceQuad(float(m_width), float(m_height), m_texelHalf, caps->originBottomLeft); + bgfx::submit(view, m_shadowsProgram); + ++view; + } + + // Shade gbuffer + { + bgfx::setViewName(view, "combine"); + + bgfx::setViewRect(view, 0, 0, uint16_t(m_width), uint16_t(m_height)); + bgfx::setViewTransform(view, NULL, orthoProj); + bgfx::setViewFrameBuffer(view, BGFX_INVALID_HANDLE); + bgfx::setState(0 + | BGFX_STATE_WRITE_RGB + | BGFX_STATE_WRITE_A + | BGFX_STATE_DEPTH_TEST_ALWAYS + ); + bgfx::setTexture(0, s_color, m_gbufferTex[GBUFFER_RT_COLOR]); + bgfx::setTexture(1, s_normal, m_gbufferTex[GBUFFER_RT_NORMAL]); + bgfx::setTexture(2, s_depth, m_linearDepth.m_texture); + bgfx::setTexture(3, s_shadows, m_shadows.m_texture); + m_uniforms.submit(); + screenSpaceQuad(float(m_width), float(m_height), m_texelHalf, caps->originBottomLeft); + bgfx::submit(view, m_combineProgram); + ++view; + } + + // Draw UI + imguiBeginFrame(m_mouseState.m_mx + , m_mouseState.m_my + , (m_mouseState.m_buttons[entry::MouseButton::Left] ? IMGUI_MBUT_LEFT : 0) + | (m_mouseState.m_buttons[entry::MouseButton::Right] ? IMGUI_MBUT_RIGHT : 0) + | (m_mouseState.m_buttons[entry::MouseButton::Middle] ? IMGUI_MBUT_MIDDLE : 0) + , m_mouseState.m_mz + , uint16_t(m_width) + , uint16_t(m_height) + ); + + showExampleDialog(this); + + ImGui::SetNextWindowPos( + ImVec2(m_width - m_width / 4.0f - 10.0f, 10.0f) + , ImGuiCond_FirstUseEver + ); + ImGui::SetNextWindowSize( + ImVec2(m_width / 4.0f, m_height / 2.3f) + , ImGuiCond_FirstUseEver + ); + ImGui::Begin("Settings" + , NULL + , 0 + ); + + ImGui::PushItemWidth(ImGui::GetWindowWidth() * 0.5f); + + { + ImGui::Text("shadow controls:"); + ImGui::Checkbox("screen space radius", &m_useScreenSpaceRadius); + if (ImGui::IsItemHovered()) + ImGui::SetTooltip("define radius in pixels or world units"); + + if (m_useScreenSpaceRadius) + { + ImGui::SliderFloat("radius in pixels", &m_shadowRadiusPixels, 1.0f, 100.0f); + } + else + { + ImGui::SliderFloat("radius in world units", &m_shadowRadius, 1e-3f, 1.0f); + } + + ImGui::SliderInt("shadow steps", &m_shadowSteps, 1, 64); + if (ImGui::IsItemHovered()) + ImGui::SetTooltip("number of steps/samples to take between shaded pixel and radius"); + + ImGui::Combo("contact shadows mode", &m_contactShadowsMode, "hard\0soft\0very soft\0\0"); + if (ImGui::IsItemHovered()) + { + ImGui::BeginTooltip(); + ImGui::Text("hard"); + ImGui::BulletText("any occluder, fully shadowed"); + ImGui::Text("soft"); + ImGui::BulletText("modulate shadow by distance to first occluder"); + ImGui::Text("very soft"); + ImGui::BulletText("also reduce each shadow contribution by distance"); + ImGui::EndTooltip(); + } + + ImGui::Checkbox("add random offset to initial position", &m_useNoiseOffset); + if (ImGui::IsItemHovered()) + ImGui::SetTooltip("hide banding with noise"); + + ImGui::Checkbox("use different offset each frame", &m_dynamicNoise); + ImGui::Separator(); + + ImGui::Text("scene controls:"); + ImGui::Checkbox("display shadows only", &m_displayShadows); + ImGui::Checkbox("move light", &m_moveLight); + } + + ImGui::End(); + + imguiEndFrame(); + + // Advance to next frame. Rendering thread will be kicked to + // process submitted rendering primitives. + m_currFrame = bgfx::frame(); + + return true; + } + + return false; + } + + void drawAllModels(bgfx::ViewId _pass, bgfx::ProgramHandle _program, const Uniforms & _uniforms) + { + for (uint32_t ii = 0; ii < BX_COUNTOF(m_models); ++ii) + { + const Model& model = m_models[ii]; + + // Set up transform matrix for each model + const float scale = s_meshScale[model.mesh]; + float mtx[16]; + bx::mtxSRT(mtx + , scale + , scale + , scale + , 0.0f + , 0.0f + , 0.0f + , model.position[0] + , model.position[1] + , model.position[2] + ); + + // Submit mesh to gbuffer + bgfx::setTexture(0, s_albedo, m_groundTexture); + bgfx::setTexture(1, s_normal, m_normalTexture); + _uniforms.submit(); + + meshSubmit(m_meshes[model.mesh], _pass, _program, mtx); + } + + // Draw ground + float mtxScale[16]; + const float scale = 10.0f; + bx::mtxScale(mtxScale, scale, scale, scale); + + float mtxTranslate[16]; + bx::mtxTranslate(mtxTranslate + , 0.0f + , -10.0f + , 0.0f + ); + + float mtx[16]; + bx::mtxMul(mtx, mtxScale, mtxTranslate); + bgfx::setTexture(0, s_albedo, m_groundTexture); + bgfx::setTexture(1, s_normal, m_normalTexture); + _uniforms.submit(); + + meshSubmit(m_ground, _pass, _program, mtx); + } + + void createFramebuffers() + { + m_size[0] = m_width; + m_size[1] = m_height; + + const uint64_t pointSampleFlags = 0 + | BGFX_TEXTURE_RT + | BGFX_SAMPLER_U_CLAMP + | BGFX_SAMPLER_V_CLAMP + | BGFX_SAMPLER_MIN_POINT + | BGFX_SAMPLER_MAG_POINT + | BGFX_SAMPLER_MIP_POINT + ; + + m_gbufferTex[GBUFFER_RT_COLOR] = bgfx::createTexture2D(uint16_t(m_size[0]), uint16_t(m_size[1]), false, 1, bgfx::TextureFormat::BGRA8, pointSampleFlags); + m_gbufferTex[GBUFFER_RT_NORMAL] = bgfx::createTexture2D(uint16_t(m_size[0]), uint16_t(m_size[1]), false, 1, bgfx::TextureFormat::BGRA8, pointSampleFlags); + m_gbufferTex[GBUFFER_RT_DEPTH] = bgfx::createTexture2D(uint16_t(m_size[0]), uint16_t(m_size[1]), false, 1, bgfx::TextureFormat::D32F, pointSampleFlags); + m_gbuffer = bgfx::createFrameBuffer(BX_COUNTOF(m_gbufferTex), m_gbufferTex, true); + + m_linearDepth.init(m_size[0], m_size[1], bgfx::TextureFormat::R16F, pointSampleFlags); + m_shadows.init(m_size[0], m_size[1], bgfx::TextureFormat::R16F, pointSampleFlags); + } + + // all buffers set to destroy their textures + void destroyFramebuffers() + { + bgfx::destroy(m_gbuffer); + + m_linearDepth.destroy(); + m_shadows.destroy(); + } + + void updateUniforms() + { + m_uniforms.m_displayShadows = m_displayShadows ? 1.0f : 0.0f; + m_uniforms.m_frameIdx = m_dynamicNoise + ? float(m_currFrame % 8) + : 0.0f; + m_uniforms.m_shadowRadius = m_useScreenSpaceRadius ? m_shadowRadiusPixels : m_shadowRadius; + m_uniforms.m_shadowSteps = float(m_shadowSteps); + m_uniforms.m_useNoiseOffset = m_useNoiseOffset ? 1.0f : 0.0f; + m_uniforms.m_contactShadowsMode = float(m_contactShadowsMode); + m_uniforms.m_useScreenSpaceRadius = m_useScreenSpaceRadius ? 1.0f : 0.0f; + + mat4Set(m_uniforms.m_worldToView, m_view); + mat4Set(m_uniforms.m_viewToProj, m_proj); + + // from assao sample, cs_assao_prepare_depths.sc + { + // float depthLinearizeMul = ( clipFar * clipNear ) / ( clipFar - clipNear ); + // float depthLinearizeAdd = clipFar / ( clipFar - clipNear ); + // correct the handedness issue. need to make sure this below is correct, but I think it is. + + float depthLinearizeMul = -m_proj2[3*4+2]; + float depthLinearizeAdd = m_proj2[2*4+2]; + + if (depthLinearizeMul * depthLinearizeAdd < 0) + { + depthLinearizeAdd = -depthLinearizeAdd; + } + + vec2Set(m_uniforms.m_depthUnpackConsts, depthLinearizeMul, depthLinearizeAdd); + + float tanHalfFOVY = 1.0f / m_proj2[1*4+1]; // = tanf( drawContext.Camera.GetYFOV( ) * 0.5f ); + float tanHalfFOVX = 1.0F / m_proj2[0]; // = tanHalfFOVY * drawContext.Camera.GetAspect( ); + + if (bgfx::getRendererType() == bgfx::RendererType::OpenGL) + { + vec2Set(m_uniforms.m_ndcToViewMul, tanHalfFOVX * 2.0f, tanHalfFOVY * 2.0f); + vec2Set(m_uniforms.m_ndcToViewAdd, tanHalfFOVX * -1.0f, tanHalfFOVY * -1.0f); + } + else + { + vec2Set(m_uniforms.m_ndcToViewMul, tanHalfFOVX * 2.0f, tanHalfFOVY * -2.0f); + vec2Set(m_uniforms.m_ndcToViewAdd, tanHalfFOVX * -1.0f, tanHalfFOVY * 1.0f); + } + } + + { + float lightPosition[4]; + bx::memCopy(lightPosition, m_lightModel.position, 3*sizeof(float)); + lightPosition[3] = 1.0f; + float viewSpaceLightPosition[4]; + bx::vec4MulMtx(viewSpaceLightPosition, lightPosition, m_view); + bx::memCopy(m_uniforms.m_lightPosition, viewSpaceLightPosition, 3*sizeof(float)); + } + } + + + uint32_t m_width; + uint32_t m_height; + uint32_t m_debug; + uint32_t m_reset; + + entry::MouseState m_mouseState; + + // Resource handles + bgfx::ProgramHandle m_gbufferProgram; + bgfx::ProgramHandle m_sphereProgram; + bgfx::ProgramHandle m_linearDepthProgram; + bgfx::ProgramHandle m_shadowsProgram; + bgfx::ProgramHandle m_combineProgram; + + // Shader uniforms + Uniforms m_uniforms; + + // Uniforms to identify texture samplers + bgfx::UniformHandle s_albedo; + bgfx::UniformHandle s_color; + bgfx::UniformHandle s_normal; + bgfx::UniformHandle s_depth; + bgfx::UniformHandle s_shadows; + + bgfx::FrameBufferHandle m_gbuffer; + bgfx::TextureHandle m_gbufferTex[GBUFFER_RENDER_TARGETS]; + + RenderTarget m_linearDepth; + RenderTarget m_shadows; + + struct Model + { + uint32_t mesh; // Index of mesh in m_meshes + float position[3]; + }; + + Model m_lightModel; + Model m_models[MODEL_COUNT]; + Mesh* m_meshes[BX_COUNTOF(s_meshPaths)]; + Mesh* m_ground; + bgfx::TextureHandle m_groundTexture; + bgfx::TextureHandle m_normalTexture; + + uint32_t m_currFrame; + float m_lightRotation = 0.0f; + float m_texelHalf = 0.0f; + float m_fovY = 60.0f; + bool m_recreateFrameBuffers = false; + bool m_havePrevious = false; + + float m_view[16]; + float m_proj[16]; + float m_proj2[16]; + int32_t m_size[2]; + + // UI parameters + bool m_displayShadows = false; + bool m_useNoiseOffset = true; + bool m_dynamicNoise = true; + float m_shadowRadius = 0.25f; + float m_shadowRadiusPixels = 25.0f; + int32_t m_shadowSteps = 8; + bool m_moveLight = true; + int32_t m_contactShadowsMode = 0; + bool m_useScreenSpaceRadius = false; +}; + +} // namespace + +ENTRY_IMPLEMENT_MAIN( + ExampleScreenSpaceShadows + , "44-sss" + , "Screen Space Shadows." + ); |