/* ** DrawTriangle code generation ** Copyright (c) 2016 Magnus Norddahl ** ** This software is provided 'as-is', without any express or implied ** warranty. In no event will the authors be held liable for any damages ** arising from the use of this software. ** ** Permission is granted to anyone to use this software for any purpose, ** including commercial applications, and to alter it and redistribute it ** freely, subject to the following restrictions: ** ** 1. The origin of this software must not be misrepresented; you must not ** claim that you wrote the original software. If you use this software ** in a product, an acknowledgment in the product documentation would be ** appreciated but is not required. ** 2. Altered source versions must be plainly marked as such, and must not be ** misrepresented as being the original software. ** 3. This notice may not be removed or altered from any source distribution. ** */ #include "i_system.h" #include "r_compiler/llvm_include.h" #include "r_compiler/fixedfunction/drawtrianglecodegen.h" #include "r_compiler/ssa/ssa_function.h" #include "r_compiler/ssa/ssa_scope.h" #include "r_compiler/ssa/ssa_for_block.h" #include "r_compiler/ssa/ssa_if_block.h" #include "r_compiler/ssa/ssa_stack.h" #include "r_compiler/ssa/ssa_function.h" #include "r_compiler/ssa/ssa_struct_type.h" #include "r_compiler/ssa/ssa_value.h" void DrawTriangleCodegen::Generate(TriDrawVariant variant, bool truecolor, SSAValue args, SSAValue thread_data) { LoadArgs(variant, truecolor, args, thread_data); Setup(variant, truecolor); LoopBlockY(variant, truecolor); } SSAInt DrawTriangleCodegen::FloatTo28_4(SSAFloat v) { // SSAInt(SSAFloat::round(16.0f * v), false); SSAInt a = SSAInt(v * 32.0f, false); return (a + (a.ashr(31) | SSAInt(1))).ashr(1); } void DrawTriangleCodegen::Setup(TriDrawVariant variant, bool truecolor) { int pixelsize = truecolor ? 4 : 1; // 28.4 fixed-point coordinates Y1 = FloatTo28_4(v1.y); Y2 = FloatTo28_4(v2.y); Y3 = FloatTo28_4(v3.y); X1 = FloatTo28_4(v1.x); X2 = FloatTo28_4(v2.x); X3 = FloatTo28_4(v3.x); // Deltas DX12 = X1 - X2; DX23 = X2 - X3; DX31 = X3 - X1; DY12 = Y1 - Y2; DY23 = Y2 - Y3; DY31 = Y3 - Y1; // Fixed-point deltas FDX12 = DX12 << 4; FDX23 = DX23 << 4; FDX31 = DX31 << 4; FDY12 = DY12 << 4; FDY23 = DY23 << 4; FDY31 = DY31 << 4; // Bounding rectangle minx = SSAInt::MAX((SSAInt::MIN(SSAInt::MIN(X1, X2), X3) + 0xF) >> 4, clipleft); maxx = SSAInt::MIN((SSAInt::MAX(SSAInt::MAX(X1, X2), X3) + 0xF) >> 4, clipright - 1); miny = SSAInt::MAX((SSAInt::MIN(SSAInt::MIN(Y1, Y2), Y3) + 0xF) >> 4, cliptop); maxy = SSAInt::MIN((SSAInt::MAX(SSAInt::MAX(Y1, Y2), Y3) + 0xF) >> 4, clipbottom - 1); SSAIfBlock if0; if0.if_block(minx >= maxx || miny >= maxy); if0.end_retvoid(); // Start in corner of 8x8 block minx = minx & ~(q - 1); miny = miny & ~(q - 1); dest = dest[miny * pitch * pixelsize]; subsectorGBuffer = subsectorGBuffer[miny * pitch]; // Half-edge constants C1 = DY12 * X1 - DX12 * Y1; C2 = DY23 * X2 - DX23 * Y2; C3 = DY31 * X3 - DX31 * Y3; // Correct for fill convention SSAIfBlock if1; if1.if_block(DY12 < SSAInt(0) || (DY12 == SSAInt(0) && DX12 > SSAInt(0))); stack_C1.store(C1 + 1); if1.else_block(); stack_C1.store(C1); if1.end_block(); C1 = stack_C1.load(); SSAIfBlock if2; if2.if_block(DY23 < SSAInt(0) || (DY23 == SSAInt(0) && DX23 > SSAInt(0))); stack_C2.store(C2 + 1); if2.else_block(); stack_C2.store(C2); if2.end_block(); C2 = stack_C2.load(); SSAIfBlock if3; if3.if_block(DY31 < SSAInt(0) || (DY31 == SSAInt(0) && DX31 > SSAInt(0))); stack_C3.store(C3 + 1); if3.else_block(); stack_C3.store(C3); if3.end_block(); C3 = stack_C3.load(); // Gradients gradWX = gradx(v1.x, v1.y, v2.x, v2.y, v3.x, v3.y, v1.w, v2.w, v3.w); gradWY = grady(v1.x, v1.y, v2.x, v2.y, v3.x, v3.y, v1.w, v2.w, v3.w); startW = v1.w + gradWX * (SSAFloat(minx) - v1.x) + gradWY * (SSAFloat(miny) - v1.y); for (int i = 0; i < TriVertex::NumVarying; i++) { gradVaryingX[i] = gradx(v1.x, v1.y, v2.x, v2.y, v3.x, v3.y, v1.varying[i] * v1.w, v2.varying[i] * v2.w, v3.varying[i] * v3.w); gradVaryingY[i] = grady(v1.x, v1.y, v2.x, v2.y, v3.x, v3.y, v1.varying[i] * v1.w, v2.varying[i] * v2.w, v3.varying[i] * v3.w); startVarying[i] = v1.varying[i] * v1.w + gradVaryingX[i] * (SSAFloat(minx) - v1.x) + gradVaryingY[i] * (SSAFloat(miny) - v1.y); } } SSAFloat DrawTriangleCodegen::gradx(SSAFloat x0, SSAFloat y0, SSAFloat x1, SSAFloat y1, SSAFloat x2, SSAFloat y2, SSAFloat c0, SSAFloat c1, SSAFloat c2) { SSAFloat top = (c1 - c2) * (y0 - y2) - (c0 - c2) * (y1 - y2); SSAFloat bottom = (x1 - x2) * (y0 - y2) - (x0 - x2) * (y1 - y2); return top / bottom; } SSAFloat DrawTriangleCodegen::grady(SSAFloat x0, SSAFloat y0, SSAFloat x1, SSAFloat y1, SSAFloat x2, SSAFloat y2, SSAFloat c0, SSAFloat c1, SSAFloat c2) { SSAFloat top = (c1 - c2) * (x0 - x2) - (c0 - c2) * (x1 - x2); SSAFloat bottom = (x0 - x2) * (y1 - y2) - (x1 - x2) * (y0 - y2); return top / bottom; } void DrawTriangleCodegen::LoopBlockY(TriDrawVariant variant, bool truecolor) { int pixelsize = truecolor ? 4 : 1; stack_y.store(miny); stack_dest.store(dest); stack_subsectorGBuffer.store(subsectorGBuffer); SSAForBlock loop; y = stack_y.load(); dest = stack_dest.load(); subsectorGBuffer = stack_subsectorGBuffer.load(); loop.loop_block(y < maxy, 0); { SSAIfBlock branch; branch.if_block((y / q) % thread.num_cores == thread.core); { LoopBlockX(variant, truecolor); } branch.end_block(); stack_dest.store(dest[q * pitch * pixelsize]); stack_subsectorGBuffer.store(subsectorGBuffer[q * pitch]); stack_y.store(y + q); } loop.end_block(); } void DrawTriangleCodegen::LoopBlockX(TriDrawVariant variant, bool truecolor) { stack_x.store(minx); SSAForBlock loop; x = stack_x.load(); loop.loop_block(x < maxx, 0); { // Corners of block x0 = x << 4; x1 = (x + q - 1) << 4; y0 = y << 4; y1 = (y + q - 1) << 4; // Evaluate half-space functions SSABool a00 = C1 + DX12 * y0 - DY12 * x0 > SSAInt(0); SSABool a10 = C1 + DX12 * y0 - DY12 * x1 > SSAInt(0); SSABool a01 = C1 + DX12 * y1 - DY12 * x0 > SSAInt(0); SSABool a11 = C1 + DX12 * y1 - DY12 * x1 > SSAInt(0); SSAInt a = (a00.zext_int() << 0) | (a10.zext_int() << 1) | (a01.zext_int() << 2) | (a11.zext_int() << 3); SSABool b00 = C2 + DX23 * y0 - DY23 * x0 > SSAInt(0); SSABool b10 = C2 + DX23 * y0 - DY23 * x1 > SSAInt(0); SSABool b01 = C2 + DX23 * y1 - DY23 * x0 > SSAInt(0); SSABool b11 = C2 + DX23 * y1 - DY23 * x1 > SSAInt(0); SSAInt b = (b00.zext_int() << 0) | (b10.zext_int() << 1) | (b01.zext_int() << 2) | (b11.zext_int() << 3); SSABool c00 = C3 + DX31 * y0 - DY31 * x0 > SSAInt(0); SSABool c10 = C3 + DX31 * y0 - DY31 * x1 > SSAInt(0); SSABool c01 = C3 + DX31 * y1 - DY31 * x0 > SSAInt(0); SSABool c11 = C3 + DX31 * y1 - DY31 * x1 > SSAInt(0); SSAInt c = (c00.zext_int() << 0) | (c10.zext_int() << 1) | (c01.zext_int() << 2) | (c11.zext_int() << 3); // Skip block when outside an edge SSAIfBlock branch; branch.if_block(!(a == SSAInt(0) || b == SSAInt(0) || c == SSAInt(0))); // Check if block needs clipping SSABool clipneeded = clipleft > x || clipright < (x + q) || cliptop > y || clipbottom < (y + q); // Calculate varying variables for affine block SSAFloat offx0 = SSAFloat(x - minx) + 0.5f; SSAFloat offy0 = SSAFloat(y - miny) + 0.5f; SSAFloat offx1 = offx0 + SSAFloat(q); SSAFloat offy1 = offy0 + SSAFloat(q); SSAFloat rcpWTL = 1.0f / (startW + offx0 * gradWX + offy0 * gradWY); SSAFloat rcpWTR = 1.0f / (startW + offx1 * gradWX + offy0 * gradWY); SSAFloat rcpWBL = 1.0f / (startW + offx0 * gradWX + offy1 * gradWY); SSAFloat rcpWBR = 1.0f / (startW + offx1 * gradWX + offy1 * gradWY); for (int i = 0; i < TriVertex::NumVarying; i++) { varyingTL[i] = (startVarying[i] + offx0 * gradVaryingX[i] + offy0 * gradVaryingY[i]) * rcpWTL; varyingTR[i] = (startVarying[i] + offx1 * gradVaryingX[i] + offy0 * gradVaryingY[i]) * rcpWTR; varyingBL[i] = ((startVarying[i] + offx0 * gradVaryingX[i] + offy1 * gradVaryingY[i]) * rcpWBL - varyingTL[i]) * (1.0f / q); varyingBR[i] = ((startVarying[i] + offx1 * gradVaryingX[i] + offy1 * gradVaryingY[i]) * rcpWBR - varyingTR[i]) * (1.0f / q); } SSAFloat globVis = SSAFloat(1706.0f); SSAFloat vis = globVis / rcpWTL; SSAFloat shade = 64.0f - (SSAFloat(light * 255 / 256) + 12.0f) * 32.0f / 128.0f; SSAFloat lightscale = SSAFloat::clamp((shade - SSAFloat::MIN(SSAFloat(24.0f), vis)) / 32.0f, SSAFloat(0.0f), SSAFloat(31.0f / 32.0f)); diminishedlight = SSAInt(SSAFloat::clamp((1.0f - lightscale) * 256.0f + 0.5f, SSAFloat(0.0f), SSAFloat(256.0f)), false); SetStencilBlock(x / 8 + y / 8 * stencilPitch); SSABool covered = a == SSAInt(0xF) && b == SSAInt(0xF) && c == SSAInt(0xF) && !clipneeded; if (variant != TriDrawVariant::DrawSubsector) { covered = covered && StencilIsSingleValue(); } // Accept whole block when totally covered SSAIfBlock branch_covered; branch_covered.if_block(covered); { LoopFullBlock(variant, truecolor); } branch_covered.else_block(); { LoopPartialBlock(variant, truecolor); } branch_covered.end_block(); branch.end_block(); stack_x.store(x + q); } loop.end_block(); } void DrawTriangleCodegen::LoopFullBlock(TriDrawVariant variant, bool truecolor) { SSAIfBlock branch_stenciltest; if (variant != TriDrawVariant::DrawSubsector) { branch_stenciltest.if_block(StencilGetSingle() == stencilTestValue); } if (variant == TriDrawVariant::Stencil) { StencilClear(stencilWriteValue); } else { int pixelsize = truecolor ? 4 : 1; stack_iy.store(SSAInt(0)); stack_buffer.store(dest); stack_subsectorbuffer.store(subsectorGBuffer); SSAForBlock loopy; SSAInt iy = stack_iy.load(); SSAUBytePtr buffer = stack_buffer.load(); SSAIntPtr subsectorbuffer = stack_subsectorbuffer.load(); loopy.loop_block(iy < SSAInt(q), q); { SSAInt varyingStep[TriVertex::NumVarying]; for (int i = 0; i < TriVertex::NumVarying; i++) { SSAFloat pos = varyingTL[i] + varyingBL[i] * SSAFloat(iy); SSAFloat step = (varyingTR[i] + varyingBR[i] * SSAFloat(iy) - pos) * (1.0f / q); stack_varying[i].store(SSAInt((pos - SSAFloat::floor(pos)) * SSAFloat((float)0x100000000LL), true)); varyingStep[i] = SSAInt(step * SSAFloat((float)0x100000000LL), true); } stack_ix.store(x); SSAForBlock loopx; SSAInt ix = stack_ix.load(); SSAInt varying[TriVertex::NumVarying]; for (int i = 0; i < TriVertex::NumVarying; i++) varying[i] = stack_varying[i].load(); loopx.loop_block(ix < x + q, q); { if (variant == TriDrawVariant::DrawSubsector) { SSAIfBlock branch; branch.if_block(subsectorbuffer[ix].load(true) >= subsectorDepth); { if (truecolor) ProcessPixel(buffer[ix * 4], subsectorbuffer[ix], varying, variant, truecolor); else ProcessPixel(buffer[ix], subsectorbuffer[ix], varying, variant, truecolor); } branch.end_block(); } else { if (truecolor) ProcessPixel(buffer[ix * 4], subsectorbuffer[ix], varying, variant, truecolor); else ProcessPixel(buffer[ix], subsectorbuffer[ix], varying, variant, truecolor); } for (int i = 0; i < TriVertex::NumVarying; i++) stack_varying[i].store(varying[i] + varyingStep[i]); stack_ix.store(ix + 1); } loopx.end_block(); stack_buffer.store(buffer[pitch * pixelsize]); stack_subsectorbuffer.store(subsectorbuffer[pitch]); stack_iy.store(iy + 1); } loopy.end_block(); } if (variant != TriDrawVariant::DrawSubsector) { branch_stenciltest.end_block(); } } void DrawTriangleCodegen::LoopPartialBlock(TriDrawVariant variant, bool truecolor) { int pixelsize = truecolor ? 4 : 1; stack_CY1.store(C1 + DX12 * y0 - DY12 * x0); stack_CY2.store(C2 + DX23 * y0 - DY23 * x0); stack_CY3.store(C3 + DX31 * y0 - DY31 * x0); stack_iy.store(SSAInt(0)); stack_buffer.store(dest); stack_subsectorbuffer.store(subsectorGBuffer); SSAForBlock loopy; SSAInt iy = stack_iy.load(); SSAUBytePtr buffer = stack_buffer.load(); SSAIntPtr subsectorbuffer = stack_subsectorbuffer.load(); SSAInt CY1 = stack_CY1.load(); SSAInt CY2 = stack_CY2.load(); SSAInt CY3 = stack_CY3.load(); loopy.loop_block(iy < SSAInt(q), q); { SSAInt varyingStep[TriVertex::NumVarying]; for (int i = 0; i < TriVertex::NumVarying; i++) { SSAFloat pos = varyingTL[i] + varyingBL[i] * SSAFloat(iy); SSAFloat step = (varyingTR[i] + varyingBR[i] * SSAFloat(iy) - pos) * (1.0f / q); stack_varying[i].store(SSAInt((pos - SSAFloat::floor(pos)) * SSAFloat((float)0x100000000LL), true)); varyingStep[i] = SSAInt(step * SSAFloat((float)0x100000000LL), true); } stack_CX1.store(CY1); stack_CX2.store(CY2); stack_CX3.store(CY3); stack_ix.store(SSAInt(0)); SSAForBlock loopx; SSAInt ix = stack_ix.load(); SSAInt CX1 = stack_CX1.load(); SSAInt CX2 = stack_CX2.load(); SSAInt CX3 = stack_CX3.load(); SSAInt varying[TriVertex::NumVarying]; for (int i = 0; i < TriVertex::NumVarying; i++) varying[i] = stack_varying[i].load(); loopx.loop_block(ix < SSAInt(q), q); { SSABool visible = (ix + x >= clipleft) && (ix + x < clipright) && (cliptop <= y + iy) && (clipbottom > y + iy); SSABool covered = CX1 > SSAInt(0) && CX2 > SSAInt(0) && CX3 > SSAInt(0) && visible; if (variant == TriDrawVariant::DrawSubsector) { covered = covered && subsectorbuffer[ix + x].load(true) >= subsectorDepth; } else { covered = covered && StencilGet(ix, iy) == stencilTestValue; } SSAIfBlock branch; branch.if_block(covered); { if (variant == TriDrawVariant::Stencil) { StencilSet(ix, iy, stencilWriteValue); } else { if (truecolor) ProcessPixel(buffer[(ix + x) * 4], subsectorbuffer[ix + x], varying, variant, truecolor); else ProcessPixel(buffer[ix + x], subsectorbuffer[ix + x], varying, variant, truecolor); } } branch.end_block(); for (int i = 0; i < TriVertex::NumVarying; i++) stack_varying[i].store(varying[i] + varyingStep[i]); stack_CX1.store(CX1 - FDY12); stack_CX2.store(CX2 - FDY23); stack_CX3.store(CX3 - FDY31); stack_ix.store(ix + 1); } loopx.end_block(); stack_CY1.store(CY1 + FDX12); stack_CY2.store(CY2 + FDX23); stack_CY3.store(CY3 + FDX31); stack_buffer.store(buffer[pitch * pixelsize]); stack_subsectorbuffer.store(subsectorbuffer[pitch]); stack_iy.store(iy + 1); } loopy.end_block(); } void DrawTriangleCodegen::ProcessPixel(SSAUBytePtr buffer, SSAIntPtr subsectorbuffer, SSAInt *varying, TriDrawVariant variant, bool truecolor) { if (variant == TriDrawVariant::Fill) { if (truecolor) { buffer.store_vec4ub(SSAVec4i::unpack(solidcolor)); } else { //buffer.store(solidcolor); } subsectorbuffer.store(subsectorDepth); } else { SSAInt ufrac = varying[0]; SSAInt vfrac = varying[1]; SSAInt upos = ((ufrac >> 16) * textureWidth) >> 16; SSAInt vpos = ((vfrac >> 16) * textureHeight) >> 16; SSAInt uvoffset = upos * textureHeight + vpos; if (truecolor) { SSAVec4i fg = texturePixels[uvoffset * 4].load_vec4ub(true); SSAInt fg_alpha = fg[3]; fg = (fg * diminishedlight) >> 8; fg.insert(3, fg_alpha); if (variant == TriDrawVariant::DrawMasked || variant == TriDrawVariant::DrawSubsector) { SSAIfBlock branch_transparency; branch_transparency.if_block(fg_alpha > SSAInt(127)); { buffer.store_vec4ub(fg); if (variant != TriDrawVariant::DrawSubsector) subsectorbuffer.store(subsectorDepth); } branch_transparency.end_block(); } else { buffer.store_vec4ub(fg); subsectorbuffer.store(subsectorDepth); } } else { SSAUByte palindex = texturePixels[uvoffset].load(true); if (variant == TriDrawVariant::DrawMasked || variant == TriDrawVariant::DrawSubsector) { SSAIfBlock branch_transparency; branch_transparency.if_block(!(palindex.zext_int() == SSAInt(0))); { buffer.store(palindex); if (variant != TriDrawVariant::DrawSubsector) subsectorbuffer.store(subsectorDepth); } branch_transparency.end_block(); } else { buffer.store(palindex); subsectorbuffer.store(subsectorDepth); } } } } void DrawTriangleCodegen::SetStencilBlock(SSAInt block) { StencilBlock = stencilValues[block * 64]; StencilBlockMask = stencilMasks[block]; } void DrawTriangleCodegen::StencilSet(SSAInt x, SSAInt y, SSAUByte value) { SSAInt mask = StencilBlockMask.load(false); SSAIfBlock branchNeedsUpdate; branchNeedsUpdate.if_block(!(mask == (SSAInt(0xffffff00) | value.zext_int()))); SSAIfBlock branchFirstSet; branchFirstSet.if_block((mask & SSAInt(0xffffff00)) == SSAInt(0xffffff00)); { SSAUByte val0 = mask.trunc_ubyte(); for (int i = 0; i < 8 * 8; i++) StencilBlock[i].store(val0); StencilBlockMask.store(SSAInt(0)); } branchFirstSet.end_block(); StencilBlock[x + y * 8].store(value); branchNeedsUpdate.end_block(); } SSAUByte DrawTriangleCodegen::StencilGet(SSAInt x, SSAInt y) { return StencilIsSingleValue().select(StencilBlockMask.load(false).trunc_ubyte(), StencilBlock[x + y * 8].load(false)); } SSAUByte DrawTriangleCodegen::StencilGetSingle() { return StencilBlockMask.load(false).trunc_ubyte(); } void DrawTriangleCodegen::StencilClear(SSAUByte value) { StencilBlockMask.store(SSAInt(0xffffff00) | value.zext_int()); } SSABool DrawTriangleCodegen::StencilIsSingleValue() { return (StencilBlockMask.load(false) & SSAInt(0xffffff00)) == SSAInt(0xffffff00); } void DrawTriangleCodegen::LoadArgs(TriDrawVariant variant, bool truecolor, SSAValue args, SSAValue thread_data) { dest = args[0][0].load(true); pitch = args[0][1].load(true); v1 = LoadTriVertex(args[0][2].load(true)); v2 = LoadTriVertex(args[0][3].load(true)); v3 = LoadTriVertex(args[0][4].load(true)); clipleft = args[0][5].load(true); clipright = args[0][6].load(true); cliptop = args[0][7].load(true); clipbottom = args[0][8].load(true); texturePixels = args[0][9].load(true); textureWidth = args[0][10].load(true); textureHeight = args[0][11].load(true); solidcolor = args[0][12].load(true); LoadUniforms(args[0][13].load(true)); stencilValues = args[0][14].load(true); stencilMasks = args[0][15].load(true); stencilPitch = args[0][16].load(true); stencilTestValue = args[0][17].load(true); stencilWriteValue = args[0][18].load(true); subsectorGBuffer = args[0][19].load(true); thread.core = thread_data[0][0].load(true); thread.num_cores = thread_data[0][1].load(true); } SSATriVertex DrawTriangleCodegen::LoadTriVertex(SSAValue ptr) { SSATriVertex v; v.x = ptr[0][0].load(true); v.y = ptr[0][1].load(true); v.z = ptr[0][2].load(true); v.w = ptr[0][3].load(true); for (int i = 0; i < TriVertex::NumVarying; i++) v.varying[i] = ptr[0][4 + i].load(true); return v; } void DrawTriangleCodegen::LoadUniforms(SSAValue uniforms) { light = uniforms[0][0].load(true); subsectorDepth = uniforms[0][1].load(true); SSAShort light_alpha = uniforms[0][2].load(true); SSAShort light_red = uniforms[0][3].load(true); SSAShort light_green = uniforms[0][4].load(true); SSAShort light_blue = uniforms[0][5].load(true); SSAShort fade_alpha = uniforms[0][6].load(true); SSAShort fade_red = uniforms[0][7].load(true); SSAShort fade_green = uniforms[0][8].load(true); SSAShort fade_blue = uniforms[0][9].load(true); SSAShort desaturate = uniforms[0][10].load(true); SSAInt flags = uniforms[0][11].load(true); shade_constants.light = SSAVec4i(light_blue.zext_int(), light_green.zext_int(), light_red.zext_int(), light_alpha.zext_int()); shade_constants.fade = SSAVec4i(fade_blue.zext_int(), fade_green.zext_int(), fade_red.zext_int(), fade_alpha.zext_int()); shade_constants.desaturate = desaturate.zext_int(); is_simple_shade = (flags & TriUniforms::simple_shade) == SSAInt(TriUniforms::simple_shade); is_nearest_filter = (flags & TriUniforms::nearest_filter) == SSAInt(TriUniforms::nearest_filter); }