Commit Graph

1590 Commits

Author SHA1 Message Date
bunnei 69c45ce71c gl_rasterizer: Implement texture border color. 2018-07-23 23:34:42 -04:00
bunnei 6b3e54621f maxwell_to_gl: Implement Texture::WrapMode::Border. 2018-07-23 23:34:41 -04:00
Subv ccc42702b5 GPU: Implement texture format R32F. 2018-07-23 22:21:31 -05:00
bunnei 1ff3bea6c7
Merge pull request #791 from bunnei/rg32f-rgba32f-bgra8
gl_rasterizer_cache: Implement formats BGRA8_UNORM/RGBA32_FLOAT/RG32_FLOAT
2018-07-23 20:13:19 -07:00
bunnei 2ff86f5765 maxwell_to_gl: Implement VertexAttribute::Type::UnsignedInt. 2018-07-23 23:12:14 -04:00
bunnei 92304181d5
Merge pull request #792 from lioncash/retval
gl_shader_decompiler: Correct return value of WriteTexsInstruction()
2018-07-23 20:06:48 -07:00
bunnei 47ac369180
Merge pull request #790 from bunnei/shader-print-instr
gl_shader_decompiler: Print instruction value in shader comments.
2018-07-23 19:48:47 -07:00
bunnei c2b4ff5d48
Merge pull request #788 from bunnei/shader-check-zero
gl_shader_decompiler: Check if SetRegister result is ZeroIndex.
2018-07-23 19:44:05 -07:00
Lioncash 33e2033af5 gl_shader_decompiler: Correct return value of WriteTexsInstruction()
This should be returning void, not a std::string
2018-07-23 22:31:58 -04:00
bunnei 9505283989 gl_shader_decompiler: Implement shader instruction TLDS. 2018-07-23 22:02:51 -04:00
bunnei a27c0099ed gl_rasterizer_cache: Implement RenderTargetFormat RG32_FLOAT. 2018-07-23 21:22:54 -04:00
bunnei 3a19c1098d gl_rasterizer_cache: Implement RenderTargetFormat RGBA32_FLOAT. 2018-07-23 21:22:53 -04:00
bunnei bcc184acfa gl_rasterizer_cache: Implement RenderTargetFormat BGRA8_UNORM. 2018-07-23 21:22:44 -04:00
bunnei 89db8c2171 gl_rasterizer_cache: Add missing log statements. 2018-07-23 21:20:09 -04:00
bunnei c4322ce87e gl_shader_decompiler: Print instruction value in shader comments. 2018-07-23 21:11:05 -04:00
bunnei 81aa02424b gl_shader_decompiler: Check if SetRegister result is ZeroIndex. 2018-07-23 21:08:40 -04:00
Lioncash 3b88ce3dcb gl_shader_decompiler: Simplify GetCommonDeclarations() 2018-07-23 17:11:18 -04:00
bunnei e85a528bb9
Merge pull request #769 from bunnei/shader-mask-fixes
shader_bytecode: Implement other TEXS masks.
2018-07-22 18:03:31 -07:00
Lioncash 0797657bc0 gl_shader_decompiler: Remove redundant Subroutine construction in AddSubroutine()
We don't need to toss away the Subroutine instance after the find() call
and reconstruct another instance with the same data right after it.
Particularly give Subroutine contains a std::set.
2018-07-22 03:30:35 -04:00
bunnei 148a5bef7e shader_bytecode: Implement other TEXS masks. 2018-07-22 03:23:15 -04:00
bunnei af4bde8cd1
Merge pull request #767 from bunnei/shader-cleanup
gl_shader_decompiler: Remove unused state tracking and minor cleanup.
2018-07-22 00:03:17 -07:00
bunnei f5a2944ab6 gl_shader_decompiler: Remove unused state tracking and minor cleanup. 2018-07-22 01:00:44 -04:00
bunnei c43eaa94f3 gl_shader_decompiler: Implement SEL instruction. 2018-07-22 00:37:12 -04:00
bunnei 63fbf9a7d3 gl_rasterizer_cache: Blit surfaces on recreation instead of flush and load. 2018-07-21 21:51:06 -04:00
bunnei 4301f0b539 gl_rasterizer_cache: Use GPUVAddr as cache key, not parameter set. 2018-07-21 21:51:06 -04:00
bunnei cd47391c2d gl_rasterizer_cache: Use zeta_width and zeta_height registers for depth buffer. 2018-07-21 21:51:06 -04:00
bunnei d8c60029d6 gl_rasterizer: Use zeta_enable register to enable depth buffer. 2018-07-21 21:51:06 -04:00
bunnei 5287991a36 maxwell_3d: Add depth buffer enable, width, and height registers. 2018-07-21 21:51:05 -04:00
bunnei 3ac736c003
Merge pull request #748 from lioncash/namespace
video_core: Use nested namespaces where applicable
2018-07-21 18:50:14 -07:00
bunnei ff8754f921
Merge pull request #747 from lioncash/unimplemented
gl_shader_manager: Remove unimplemented function prototype
2018-07-21 10:54:58 -07:00
Lioncash d5bc9aef4e gl_shader_manager: Replace unimplemented function prototype
This was just a linker error waiting to happen.
2018-07-20 18:39:54 -04:00
Lioncash 863579736c gpu: Rename Get3DEngine() to Maxwell3D()
This makes it match its const qualified equivalent.
2018-07-20 18:34:49 -04:00
Lioncash bb960c8cb4 video_core: Use nested namespaces where applicable
Compresses a few namespace specifiers to be more compact.
2018-07-20 18:23:54 -04:00
bunnei 29f49bd3c1
Merge pull request #738 from lioncash/sign
gl_state: Get rid of mismatched sign conversions in Apply()
2018-07-20 09:21:57 -07:00
bunnei fbc2bcd4a9
Merge pull request #735 from lioncash/video-unused
maxwell_3d: Remove unused variable within GetStageTextures()
2018-07-20 09:16:15 -07:00
bunnei 204d707ce7
Merge pull request #731 from lioncash/shadow
gl_shader_decompiler: Eliminate variable and declaration shadowing
2018-07-20 09:13:36 -07:00
Lioncash 0faa13baeb gl_state: Make references const where applicable in Apply() 2018-07-20 01:12:29 -04:00
Lioncash e6b3d3a9ea gl_state: Get rid of mismatched sign conversions
While we're at it, amend the loop variable type to be the same width as
that returned by the .size() call.
2018-07-20 01:11:20 -04:00
Lioncash 8b08f82dc7 maxwell_3d: Remove unused variable within GetStageTextures() 2018-07-19 22:38:28 -04:00
Lioncash f26866ff6a gl_shader_decompiler: Eliminate variable and declaration shadowing
Ensures that no identifiers are being hidden, which also reduces
compiler warnings.
2018-07-19 20:32:49 -04:00
Lioncash c2121cb059 gl_shader_decompiler: Remove unnecessary const from return values
This adds nothing from a behavioral point of view, and can inhibit the
move constructor/RVO
2018-07-19 20:11:04 -04:00
bunnei cf30c4be22 gl_state: Temporarily disable culling and depth test. 2018-07-18 23:21:43 -04:00
bunnei 49b0966003
Merge pull request #687 from lioncash/instance
core: Don't construct instance of Core::System, just to access its live instance
2018-07-18 18:55:58 -07:00
bunnei b496a9eefe decoders: Fix calc of swizzle image_width_in_gobs. 2018-07-18 21:42:52 -04:00
Lioncash 3a4841e403 core: Don't construct instance of Core::System, just to access its live instance
This would result in a lot of allocations and related object
construction, just to toss it all away immediately after the call.

These are definitely not intentional, and it was intended that all of
these should have been accessing the static function GetInstance()
through the name itself, not constructed instances.
2018-07-18 18:18:27 -04:00
bunnei b87a71b3fe
Merge pull request #678 from lioncash/astc
astc: Minor changes
2018-07-17 22:06:20 -07:00
Lioncash 6a03badcbc astc: Initialize vector size directly in Decompress
There's no need to perform a separate resize.
2018-07-17 23:58:14 -04:00
Lioncash 0f148548f3 astc: Mark functions as internally linked where applicable 2018-07-17 23:58:14 -04:00
Lioncash c5803e30d3 astc: const-correctness changes where applicable
A few member functions didn't actually modify class state, so these can
be amended as necessary.
2018-07-17 23:58:14 -04:00
Lioncash e3fadb9616 astc: Delete Bits' copy contstructor and assignment operator
This also potentially avoids warnings, considering the copy assignment
operator is supposed to have a return value.
2018-07-17 23:58:14 -04:00
Lioncash 4cd52a34b9 astc: In-class initialize member variables where appropriate 2018-07-17 23:58:10 -04:00
bunnei c3dd456d51 vi: Partially implement buffer crop parameters. 2018-07-17 20:13:17 -04:00
Subv 3d3b10adc7 GPU: Added register definitions for the stencil parameters. 2018-07-17 15:00:21 -05:00
bunnei 3a96670f2d gl_rasterizer_cache: Implement texture format G8R8. 2018-07-15 01:33:42 -04:00
bunnei aaec0b7e70
Merge pull request #665 from bunnei/fix-z24-s8
gl_rasterizer_cache: Fix incorrect offset in ConvertS8Z24ToZ24S8.
2018-07-14 22:18:55 -07:00
bunnei 3145114190 gl_rasterizer_cache: Fix incorrect offset in ConvertS8Z24ToZ24S8. 2018-07-15 00:02:05 -04:00
bunnei e21190f47f gl_rasterizer_cache: Implement depth format Z16_UNORM. 2018-07-14 23:43:28 -04:00
bunnei 2cb3fdca86
Merge pull request #598 from bunnei/makedonecurrent
OpenGL: Use MakeCurrent/DoneCurrent for multithreaded rendering.
2018-07-14 20:18:11 -07:00
bunnei 05cb10530f OpenGL: Use MakeCurrent/DoneCurrent for multithreaded rendering. 2018-07-14 02:50:35 -04:00
Subv b37354cca8 GPU: Always enable the depth write when clearing the depth buffer.
The GPU ignores that register when clearing, but OpenGL obeys the glDepthMask parameter, so we set the depth mask to GL_TRUE when clearing the depth buffer. It will be restored to the correct value automatically on the next draw call.
2018-07-14 00:52:23 -05:00
bunnei 8aeff9cf8e gl_rasterizer: Fix check for if a shader stage is enabled. 2018-07-12 22:57:57 -04:00
bunnei c4015cd93a gl_shader_gen: Implement dual vertex shader mode.
- When VertexA shader stage is enabled, we combine with VertexB program to make a single Vertex Shader stage.
2018-07-12 22:25:36 -04:00
bunnei 64b5e5d5d9
Merge pull request #655 from bunnei/pred-lt-nan
gl_shader_decompiler: Implement PredCondition::LessThanWithNan.
2018-07-12 18:59:15 -07:00
bunnei 49c0c081c4 gl_shader_decompiler: Implement PredCondition::LessThanWithNan. 2018-07-12 20:04:35 -04:00
bunnei 4757ffdcce gl_shader_decompiler: Use FlowCondition field in EXIT instruction. 2018-07-12 20:00:37 -04:00
Sebastian Valle 274d1fb0fc
Merge pull request #652 from Subv/fadd32i
GPU: Implement the FADD32I shader instruction.
2018-07-12 17:36:51 -05:00
bunnei 3ff21345b4
Merge pull request #651 from Subv/ffma_decode
GPU: Corrected the decoding of FFMA for immediate operands.
2018-07-12 12:42:58 -07:00
Subv c1ae841f47 GPU: Implement the FADD32I shader instruction. 2018-07-12 12:00:31 -05:00
Subv 0cad310e12 GPU: Corrected the decoding of FFMA for immediate operands. 2018-07-12 10:15:48 -05:00
bunnei 854f474f52 gl_rasterizer: Flip triangles when regs.viewport_transform[0].scale_y is negative.
- Fixes a regression with Binding of Isaac.
2018-07-08 16:16:24 -04:00
bunnei 639346bcfb
Merge pull request #625 from Subv/imnmx
GPU: Implemented the IMNMX shader instruction.
2018-07-07 19:33:50 -07:00
Subv 4633dd9505 GPU: Implemented the BC7U texture format.
Note: Our version of glad exports GL_COMPRESSED_RGBA_BPTC_UNORM as GL_COMPRESSED_RGBA_BPTC_UNORM_ARB, maybe it's time we update it.
2018-07-07 09:17:48 -05:00
bunnei 51bd76a5fd
Merge pull request #629 from Subv/depth_test
GPU: Allow using the old NV04 values for the depth test function.
2018-07-05 16:43:10 -04:00
Subv 9f6a5660e8 GPU: Allow using the old NV04 values for the depth test function.
These seem to be just a valid as the GL token values. Thanks @ReinUsesLisp

This restores graphical output to Disgaea 5
2018-07-05 13:01:31 -05:00
bunnei 762bf6a522
Merge pull request #626 from Subv/shader_sync
GPU: Stub the shader SYNC and DEPBAR instructions.
2018-07-05 12:54:19 -04:00
bunnei 637f9d780a
Merge pull request #624 from Subv/f2f_round
GPU: Implemented the F2F 'round' rounding mode.
2018-07-05 11:30:29 -04:00
bunnei 956b5db52e
Merge pull request #623 from Subv/vertex_types
GPU: Implement the Size_16_16 and Size_10_10_10_2 vertex attribute types
2018-07-05 11:30:01 -04:00
bunnei 8b815877a6
Merge pull request #622 from Subv/unused_tex
GPU: Ignore unused textures and corrected the TEX shader instruction decoding.
2018-07-05 11:29:17 -04:00
bunnei 1b0a74e23f
Merge pull request #621 from Subv/psetp_
GPU: Implemented the PSETP shader instruction.
2018-07-05 11:28:50 -04:00
bunnei 9a3c0b161e
Merge pull request #620 from Subv/depth_z32f
GPU: Implemented the 32 bit float depth buffer format.
2018-07-05 11:09:15 -04:00
Subv b0c92b80b1 GPU: Implemented the IMNMX shader instruction.
It's similar to the FMNMX instruction but it works on integers.
2018-07-04 15:44:37 -05:00
Subv d800a02b4b GPU: Implemented the F2F 'round' rounding mode.
It's implemented via the GLSL 'roundEven()' function.
2018-07-04 15:43:21 -05:00
Subv 77cfe4f027 GPU: Stub the shader SYNC and DEPBAR instructions.
It is unknown at this moment if we actually need to do something with these instructions or if the GLSL compiler takes care of that for us.
2018-07-04 15:29:51 -05:00
Subv ce39ae3e57 GPU: Implement the Size_16_16 and Size_10_10_10_2 vertex attribute types.
Both signed and unsigned variants.
2018-07-04 15:22:34 -05:00
Subv 4bda9693be GPU: Ignore textures that the GLSL compiler deemed unused when binding textures to the shaders. 2018-07-04 15:20:12 -05:00
Subv c42b818cf9 GPU: Corrected the decoding for the TEX shader instruction. 2018-07-04 15:19:20 -05:00
Subv 53a55bd751 GPU: Implemented the PSETP shader instruction.
It's similar to the isetp and fsetp instructions but it works on predicates instead.
2018-07-04 15:15:03 -05:00
Subv 016e357c75 GPU: Implemented the 32 bit float depth buffer format. 2018-07-04 10:42:33 -05:00
Subv c1bebdef5e GPU: Flip the triangle front face winding if the GPU is configured to not flip the triangles.
OpenGL's default behavior is already correct when the GPU is configured to flip the triangles.

This fixes 1-2 Switch's splash screen.
2018-07-04 10:26:46 -05:00
Subv 5a9df3c675 GPU: Only configure the used framebuffers during clear.
Don't try to configure the color buffer if it is not being cleared, it may not be completely valid at this point.
2018-07-03 22:32:59 -05:00
bunnei c996787d84
Merge pull request #609 from Subv/clear_buffers
GPU: Implemented the CLEAR_BUFFERS register.
2018-07-03 19:34:34 -04:00
Subv 78443a7f29 GPU: Factor out the framebuffer configuration code for both Clear and Draw commands. 2018-07-03 16:56:47 -05:00
Subv c1811ed3d1 GPU: Support clears that don't clear the color buffer. 2018-07-03 16:56:47 -05:00
Subv be51120d23 GPU: Bind and clear the render target when the CLEAR_BUFFERS register is written to. 2018-07-03 16:56:44 -05:00
Subv 827bb08c91 GPU: Added registers for the CLEAR_BUFFERS and CLEAR_COLOR methods. 2018-07-03 16:56:31 -05:00
bunnei 9da1552417 gl_rasterizer_cache: Implement PixelFormat S8Z24. 2018-07-03 14:58:13 -04:00
bunnei 15e68cdbaa
Merge pull request #607 from jroweboy/logging
Logging - Customizable backends
2018-07-03 00:26:45 -04:00
bunnei e3ca561ea0
Merge pull request #612 from bunnei/fix-cull
gl_rasterizer: Only set cull mode and front face if enabled.
2018-07-02 23:48:52 -04:00
bunnei ddb767f1b6
Merge pull request #611 from Subv/enabled_depth_test
GPU: Don't try to parse the depth test function if the depth test is disabled and use only the least significant 3 bits in the depth test func
2018-07-02 23:47:11 -04:00
bunnei 5410b4659d
Merge pull request #610 from Subv/mufu_8
GPU: Implemented MUFU suboperation 8, sqrt.
2018-07-02 22:26:42 -04:00
bunnei a9cacd03f6 gl_rasterizer: Only set cull mode and front face if enabled. 2018-07-02 22:22:25 -04:00
Subv 6e0eba9917 GPU: Use only the least significant 3 bits when reading the depth test func.
Some games set the full GL define value here (including nouveau), but others just seem to set those last 3 bits.
2018-07-02 21:06:36 -05:00
Subv 65c664560c GPU: Don't try to parse the depth test function if the depth test is disabled. 2018-07-02 21:02:46 -05:00
James Rowe 0d46f0df12 Update clang format 2018-07-02 21:45:47 -04:00
James Rowe 638956aa81 Rename logging macro back to LOG_* 2018-07-02 21:45:47 -04:00
bunnei 92c7135065
Merge pull request #608 from Subv/depth
GPU: Implemented the depth buffer and depth test + culling
2018-07-02 21:24:43 -04:00
Subv a6d4903aaf GPU: Set up the culling configuration on each draw. 2018-07-02 19:51:29 -05:00
Subv 6e4e0b2b41 GPU: Implemented MUFU suboperation 8, sqrt. 2018-07-02 19:48:15 -05:00
Sebastian Valle 055f1546d7
Merge pull request #606 from Subv/base_vertex
GPU: Fixed the index offset and implement BaseVertex when doing indexed rendering.
2018-07-02 14:07:38 -05:00
Sebastian Valle 9685dd5840
Merge pull request #605 from Subv/dma_copy
GPU: Directly copy the pixels when performing a same-layout DMA.
2018-07-02 14:06:56 -05:00
Subv 18c8ae7750 GPU: Set up the depth test state on every draw. 2018-07-02 13:33:06 -05:00
Subv d480b63e0d MaxwellToGL: Added conversion functions for depth test and cull mode. 2018-07-02 13:31:49 -05:00
Subv c1f55c32c8 GPU: Added registers for depth test and cull mode. 2018-07-02 13:31:20 -05:00
Subv 0f929762b3 GPU: Implemented the Z24S8 depth format and load the depth framebuffer. 2018-07-02 12:42:04 -05:00
Subv 4c59105adf GPU: Implement offsetted rendering when using non-indexed drawing. 2018-07-02 11:23:36 -05:00
Subv fca3d1cc65 GPU: Fixed the index offset rendering, and implemented the base vertex functionality.
This fixes Stardew Valley.
2018-07-02 11:22:17 -05:00
Subv cc73bad293 GPU: Added register definitions for the vertex buffer base element. 2018-07-02 11:21:23 -05:00
bunnei 3d41fdfbba
Merge pull request #604 from Subv/invalid_textures
GPU: Ignore invalid and disabled textures when drawing.
2018-07-02 11:48:18 -04:00
Subv ca633a5a3c GPU: Directly copy the pixels when performing a same-layout DMA. 2018-07-02 09:46:33 -05:00
Subv 80c5e8ae99 GPU: Ignore disabled textures and textures with an invalid address. 2018-07-02 09:43:38 -05:00
Subv e9d147349b GPU: Allow GpuToCpuAddress to return boost::none for unmapped addresses. 2018-07-02 09:42:48 -05:00
bunnei 066d6184d4
Merge pull request #602 from Subv/mufu_subop
GPU: Corrected the size of the MUFU subop field, and removed incorrect "min" operation.
2018-07-01 11:06:04 -04:00
bunnei b611d852db
Merge pull request #601 from Subv/rgba32_ui
GPU: Implement the RGBA32_UINT rendertarget format.
2018-07-01 03:22:38 -04:00
Subv f33e406ff2 GPU: Corrected the size of the MUFU subop field, and removed incorrect "min" operation. 2018-06-30 14:48:25 -05:00
Subv c0e2d52758 GPU: Implemented the RGBA32_UINT rendertarget format. 2018-06-30 14:23:13 -05:00
Subv b11072d54a GLCache: Specify the component type along the texture type in the format tuple. 2018-06-30 14:08:51 -05:00
bunnei c96da97630 gl_shader_decompiler: Implement predicate NotEqualWithNan. 2018-06-30 03:01:25 -04:00
bunnei 50ef2beb58
Merge pull request #595 from bunnei/raster-cache
Rewrite the OpenGL rasterizer cache
2018-06-29 14:07:28 -04:00
bunnei c18425ef98 gl_rasterizer_cache: Only dereference color_surface/depth_surface if valid. 2018-06-29 13:08:08 -04:00
bunnei 7fa9177830
gl_shader_decompiler: Add a return path for unknown instructions. 2018-06-27 01:14:34 -04:00
bunnei 1dd754590f gl_rasterizer_cache: Implement caching for texture and framebuffer surfaces.
gl_rasterizer_cache: Improved cache management based on Citra's implementation.

gl_surface_cache: Add some docstrings.
2018-06-27 00:15:44 -04:00
bunnei 8af1ae46aa gl_rasterizer_cache: Various fixes for ASTC handling. 2018-06-27 00:08:04 -04:00
bunnei c7c379bd19 gl_rasterizer_cache: Use SurfaceParams as a key for surface caching. 2018-06-27 00:08:04 -04:00
bunnei 6a28a66832 maxwell_3d: Add a struct for RenderTargetConfig. 2018-06-27 00:08:04 -04:00
bunnei 3f9f047375 gl_rasterizer: Implement AccelerateDisplay to forward textures to framebuffers. 2018-06-27 00:08:03 -04:00
bunnei ff6785f3e8 gl_rasterizer_cache: Cache size_in_bytes as a const per surface. 2018-06-27 00:08:03 -04:00
bunnei 9f2f819bb6 gl_rasterizer_cache: Refactor to make SurfaceParams members const. 2018-06-27 00:08:03 -04:00
bunnei 5f57ab1b2a gl_rasterizer_cache: Remove Citra's rasterizer cache, always load/flush surfaces. 2018-06-27 00:08:03 -04:00
bunnei 10422f3c18 gl_rasterizer: Workaround for when exceeding max UBO size. 2018-06-26 23:07:34 -04:00
bunnei dfac394e60
Merge pull request #593 from bunnei/fix-swizzle
gl_state: Fix state management for texture swizzle.
2018-06-26 22:05:49 -04:00
bunnei 73de9bab1a
Merge pull request #592 from bunnei/cleanup-gl-state
gl_state: Remove unused state management from 3DS.
2018-06-26 22:05:03 -04:00
bunnei 8447d20a11 gl_state: Fix state management for texture swizzle. 2018-06-26 17:15:58 -04:00
bunnei 20b58bab9c gl_state: Remove unused state management from 3DS. 2018-06-26 17:09:25 -04:00
bunnei 41b3725d28 gl_rasterizer_cache: Fix inverted B5G6R5 format. 2018-06-26 17:07:36 -04:00
bunnei 36dedae842
Merge pull request #554 from Subv/constbuffer_ubo
Rasterizer: Use UBOs instead of SSBOs for uploading const buffers.
2018-06-26 10:25:56 -04:00
mailwl ad39bab271 Fix crash at exit 2018-06-25 18:01:08 +03:00
Subv a3d82ef5d9 Build: Fixed some MSVC warnings in various parts of the code. 2018-06-20 11:39:10 -05:00
bunnei 7a0bb406d5
Merge pull request #574 from Subv/shader_abs_neg
GPU: Perform negation after absolute value in the float shader instructions.
2018-06-18 22:24:57 -04:00
Subv 38989bef43 GPU: Perform negation after absolute value in the float shader instructions. 2018-06-18 19:56:29 -05:00
Subv eab7457c00 GPU: Don't mark uniform buffers and registers as used for instructions which don't have them.
Like the MOV32I and FMUL32I instructions.
This fixes a potential crash when using these instructions.
2018-06-18 19:50:35 -05:00