From c7032066b8df092072f28776e3c92c9a8d64bfce Mon Sep 17 00:00:00 2001 From: Dragios Date: Sat, 16 Apr 2016 01:38:13 +0800 Subject: [PATCH] Implement w-buffer (#13) * Pica: Implement W-Buffer in SW rasterizer * OpenGL: Implement W-Buffers and fix depth-mapping --- src/video_core/clipper.cpp | 4 +-- src/video_core/pica.h | 20 +++++++++++--- src/video_core/rasterizer.cpp | 26 ++++++++++++++++--- .../renderer_opengl/gl_rasterizer.cpp | 11 +++++--- .../renderer_opengl/gl_rasterizer.h | 5 ++++ .../renderer_opengl/gl_shader_gen.cpp | 11 +++++++- 6 files changed, 64 insertions(+), 13 deletions(-) diff --git a/src/video_core/clipper.cpp b/src/video_core/clipper.cpp index 3d503486e..409b980ba 100644 --- a/src/video_core/clipper.cpp +++ b/src/video_core/clipper.cpp @@ -64,8 +64,6 @@ static void InitScreenCoordinates(OutputVertex& vtx) viewport.halfsize_y = float24::FromRaw(regs.viewport_size_y); viewport.offset_x = float24::FromFloat32(static_cast(regs.viewport_corner.x)); viewport.offset_y = float24::FromFloat32(static_cast(regs.viewport_corner.y)); - viewport.zscale = float24::FromRaw(regs.viewport_depth_range); - viewport.offset_z = float24::FromRaw(regs.viewport_depth_far_plane); float24 inv_w = float24::FromFloat32(1.f) / vtx.pos.w; vtx.color *= inv_w; @@ -78,7 +76,7 @@ static void InitScreenCoordinates(OutputVertex& vtx) vtx.screenpos[0] = (vtx.pos.x * inv_w + float24::FromFloat32(1.0)) * viewport.halfsize_x + viewport.offset_x; vtx.screenpos[1] = (vtx.pos.y * inv_w + float24::FromFloat32(1.0)) * viewport.halfsize_y + viewport.offset_y; - vtx.screenpos[2] = viewport.offset_z + vtx.pos.z * inv_w * viewport.zscale; + vtx.screenpos[2] = vtx.pos.z * inv_w; } void ProcessTriangle(const OutputVertex &v0, const OutputVertex &v1, const OutputVertex &v2) { diff --git a/src/video_core/pica.h b/src/video_core/pica.h index 4552ff81c..00c4fa79f 100644 --- a/src/video_core/pica.h +++ b/src/video_core/pica.h @@ -69,7 +69,7 @@ struct Regs { INSERT_PADDING_WORDS(0x9); BitField<0, 24, u32> viewport_depth_range; // float24 - BitField<0, 24, u32> viewport_depth_far_plane; // float24 + BitField<0, 24, u32> viewport_depth_near_plane; // float24 BitField<0, 3, u32> vs_output_total; @@ -121,7 +121,20 @@ struct Regs { BitField<16, 10, s32> y; } viewport_corner; - INSERT_PADDING_WORDS(0x17); + INSERT_PADDING_WORDS(0x1); + + //TODO: early depth + INSERT_PADDING_WORDS(0x1); + + INSERT_PADDING_WORDS(0x2); + + enum DepthBuffering : u32 { + WBuffering = 0, + ZBuffering = 1, + }; + BitField< 0, 1, DepthBuffering> depthmap_enable; + + INSERT_PADDING_WORDS(0x12); struct TextureConfig { enum WrapMode : u32 { @@ -1273,10 +1286,11 @@ ASSERT_REG_POSITION(cull_mode, 0x40); ASSERT_REG_POSITION(viewport_size_x, 0x41); ASSERT_REG_POSITION(viewport_size_y, 0x43); ASSERT_REG_POSITION(viewport_depth_range, 0x4d); -ASSERT_REG_POSITION(viewport_depth_far_plane, 0x4e); +ASSERT_REG_POSITION(viewport_depth_near_plane, 0x4e); ASSERT_REG_POSITION(vs_output_attributes[0], 0x50); ASSERT_REG_POSITION(vs_output_attributes[1], 0x51); ASSERT_REG_POSITION(viewport_corner, 0x68); +ASSERT_REG_POSITION(depthmap_enable, 0x6D); ASSERT_REG_POSITION(texture0_enable, 0x80); ASSERT_REG_POSITION(texture0, 0x81); ASSERT_REG_POSITION(texture0_format, 0x8e); diff --git a/src/video_core/rasterizer.cpp b/src/video_core/rasterizer.cpp index 5b9ed7c64..26ccfe70e 100644 --- a/src/video_core/rasterizer.cpp +++ b/src/video_core/rasterizer.cpp @@ -859,10 +859,30 @@ static void ProcessTriangleInternal(const Shader::OutputVertex& v0, } } + // interpolated_z = z / w + float interpolated_z_over_w = (v0.screenpos[2].ToFloat32() * w0 + + v1.screenpos[2].ToFloat32() * w1 + + v2.screenpos[2].ToFloat32() * w2) / wsum; + + // Not fully accurate. About 3 bits in precision are missing. + // Z-Buffer (z / w * scale + offset) + float depth_scale = float24::FromRaw(regs.viewport_depth_range).ToFloat32(); + float depth_offset = float24::FromRaw(regs.viewport_depth_near_plane).ToFloat32(); + float depth = interpolated_z_over_w * depth_scale + depth_offset; + + // Potentially switch to W-Buffer + if (regs.depthmap_enable == Pica::Regs::DepthBuffering::WBuffering) { + + // W-Buffer (z * scale + w * offset = (z / w * scale + offset) * w) + depth *= interpolated_w_inverse.ToFloat32() * wsum; + } + + // Clamp the result + depth = MathUtil::Clamp(depth, 0.0f, 1.0f); + + // Convert float to integer unsigned num_bits = Regs::DepthBitsPerPixel(regs.framebuffer.depth_format); - u32 z = (u32)((v0.screenpos[2].ToFloat32() * w0 + - v1.screenpos[2].ToFloat32() * w1 + - v2.screenpos[2].ToFloat32() * w2) * ((1 << num_bits) - 1) / wsum); + u32 z = (u32)(depth * ((1 << num_bits) - 1)); if (output_merger.depth_test_enable) { u32 ref_z = GetDepth(x >> 4, y >> 4); diff --git a/src/video_core/renderer_opengl/gl_rasterizer.cpp b/src/video_core/renderer_opengl/gl_rasterizer.cpp index 6ca9f45e2..19a160fdd 100644 --- a/src/video_core/renderer_opengl/gl_rasterizer.cpp +++ b/src/video_core/renderer_opengl/gl_rasterizer.cpp @@ -250,10 +250,15 @@ void RasterizerOpenGL::NotifyPicaRegisterChanged(u32 id) { // Depth modifiers case PICA_REG_INDEX(viewport_depth_range): - case PICA_REG_INDEX(viewport_depth_far_plane): + case PICA_REG_INDEX(viewport_depth_near_plane): SyncDepthModifiers(); break; + // Depth buffering + case PICA_REG_INDEX(depthmap_enable): + state.draw.shader_dirty = true; + break; + // Blending case PICA_REG_INDEX(output_merger.alphablend_enable): SyncBlendEnabled(); @@ -865,9 +870,9 @@ void RasterizerOpenGL::SyncCullMode() { void RasterizerOpenGL::SyncDepthModifiers() { float depth_scale = -Pica::float24::FromRaw(Pica::g_state.regs.viewport_depth_range).ToFloat32(); - float depth_offset = Pica::float24::FromRaw(Pica::g_state.regs.viewport_depth_far_plane).ToFloat32() / 2.0f; + float depth_offset = Pica::float24::FromRaw(Pica::g_state.regs.viewport_depth_near_plane).ToFloat32(); - // TODO: Implement scale modifier + uniform_block_data.data.depth_scale = depth_scale; uniform_block_data.data.depth_offset = depth_offset; uniform_block_data.dirty = true; } diff --git a/src/video_core/renderer_opengl/gl_rasterizer.h b/src/video_core/renderer_opengl/gl_rasterizer.h index 390349a0c..32f5b60c5 100644 --- a/src/video_core/renderer_opengl/gl_rasterizer.h +++ b/src/video_core/renderer_opengl/gl_rasterizer.h @@ -35,6 +35,8 @@ struct PicaShaderConfig { PicaShaderConfig res; const auto& regs = Pica::g_state.regs; + res.depthmap_enable = regs.depthmap_enable; + res.alpha_test_func = regs.output_merger.alpha_test.enable ? regs.output_merger.alpha_test.func.Value() : Pica::Regs::CompareFunc::Always; @@ -141,6 +143,8 @@ struct PicaShaderConfig { return std::memcmp(this, &o, sizeof(PicaShaderConfig)) == 0; }; + Pica::Regs::DepthBuffering depthmap_enable = Pica::Regs::DepthBuffering::WBuffering; + Pica::Regs::CompareFunc alpha_test_func = Pica::Regs::CompareFunc::Never; std::array tev_stages = {}; u8 combiner_buffer_input = 0; @@ -303,6 +307,7 @@ private: GLvec4 const_color[6]; GLvec4 tev_combiner_buffer_color; GLint alphatest_ref; + GLfloat depth_scale; GLfloat depth_offset; alignas(16) GLvec3 lighting_global_ambient; LightSrc light_src[8]; diff --git a/src/video_core/renderer_opengl/gl_shader_gen.cpp b/src/video_core/renderer_opengl/gl_shader_gen.cpp index ee4b54ab9..fbde93a4e 100644 --- a/src/video_core/renderer_opengl/gl_shader_gen.cpp +++ b/src/video_core/renderer_opengl/gl_shader_gen.cpp @@ -525,6 +525,7 @@ layout (std140) uniform shader_data { vec4 const_color[NUM_TEV_STAGES]; vec4 tev_combiner_buffer_color; int alphatest_ref; + float depth_scale; float depth_offset; vec3 lighting_global_ambient; LightSrc light_src[NUM_LIGHTS]; @@ -566,7 +567,15 @@ vec4 secondary_fragment_color = vec4(0.0); } out += "color = last_tex_env_out;\n"; - out += "gl_FragDepth = gl_FragCoord.z + depth_offset;\n}"; + + out += "float z_over_w = gl_FragCoord.z * 2.0 - 1.0;\n"; + out += "float depth = z_over_w * depth_scale + depth_offset;\n"; + if (config.depthmap_enable == Pica::Regs::DepthBuffering::WBuffering) { + out += "depth /= gl_FragCoord.w;\n"; + } + out += "gl_FragDepth = depth;\n"; + + out += "}"; return out; }