gioui.org/ui@v0.0.0-20190926171558-ce74bc0cbaea/app/internal/gl/gl_windows.go (about) 1 // SPDX-License-Identifier: Unlicense OR MIT 2 3 package gl 4 5 import ( 6 "math" 7 "runtime" 8 "syscall" 9 "unsafe" 10 11 "golang.org/x/sys/windows" 12 ) 13 14 var ( 15 LibGLESv2 = windows.NewLazyDLL("libGLESv2.dll") 16 _glActiveTexture = LibGLESv2.NewProc("glActiveTexture") 17 _glAttachShader = LibGLESv2.NewProc("glAttachShader") 18 _glBeginQuery = LibGLESv2.NewProc("glBeginQuery") 19 _glBindAttribLocation = LibGLESv2.NewProc("glBindAttribLocation") 20 _glBindBuffer = LibGLESv2.NewProc("glBindBuffer") 21 _glBindFramebuffer = LibGLESv2.NewProc("glBindFramebuffer") 22 _glBindRenderbuffer = LibGLESv2.NewProc("glBindRenderbuffer") 23 _glBindTexture = LibGLESv2.NewProc("glBindTexture") 24 _glBlendEquation = LibGLESv2.NewProc("glBlendEquation") 25 _glBlendFunc = LibGLESv2.NewProc("glBlendFunc") 26 _glBufferData = LibGLESv2.NewProc("glBufferData") 27 _glCheckFramebufferStatus = LibGLESv2.NewProc("glCheckFramebufferStatus") 28 _glClear = LibGLESv2.NewProc("glClear") 29 _glClearColor = LibGLESv2.NewProc("glClearColor") 30 _glClearDepthf = LibGLESv2.NewProc("glClearDepthf") 31 _glDeleteQueries = LibGLESv2.NewProc("glDeleteQueries") 32 _glCompileShader = LibGLESv2.NewProc("glCompileShader") 33 _glGenBuffers = LibGLESv2.NewProc("glGenBuffers") 34 _glGenFramebuffers = LibGLESv2.NewProc("glGenFramebuffers") 35 _glCreateProgram = LibGLESv2.NewProc("glCreateProgram") 36 _glGenRenderbuffers = LibGLESv2.NewProc("glGenRenderbuffers") 37 _glCreateShader = LibGLESv2.NewProc("glCreateShader") 38 _glGenTextures = LibGLESv2.NewProc("glGenTextures") 39 _glDeleteBuffers = LibGLESv2.NewProc("glDeleteBuffers") 40 _glDeleteFramebuffers = LibGLESv2.NewProc("glDeleteFramebuffers") 41 _glDeleteProgram = LibGLESv2.NewProc("glDeleteProgram") 42 _glDeleteShader = LibGLESv2.NewProc("glDeleteShader") 43 _glDeleteRenderbuffers = LibGLESv2.NewProc("glDeleteRenderbuffers") 44 _glDeleteTextures = LibGLESv2.NewProc("glDeleteTextures") 45 _glDepthFunc = LibGLESv2.NewProc("glDepthFunc") 46 _glDepthMask = LibGLESv2.NewProc("glDepthMask") 47 _glDisableVertexAttribArray = LibGLESv2.NewProc("glDisableVertexAttribArray") 48 _glDisable = LibGLESv2.NewProc("glDisable") 49 _glDrawArrays = LibGLESv2.NewProc("glDrawArrays") 50 _glDrawElements = LibGLESv2.NewProc("glDrawElements") 51 _glEnable = LibGLESv2.NewProc("glEnable") 52 _glEnableVertexAttribArray = LibGLESv2.NewProc("glEnableVertexAttribArray") 53 _glEndQuery = LibGLESv2.NewProc("glEndQuery") 54 _glFinish = LibGLESv2.NewProc("glFinish") 55 _glFramebufferRenderbuffer = LibGLESv2.NewProc("glFramebufferRenderbuffer") 56 _glFramebufferTexture2D = LibGLESv2.NewProc("glFramebufferTexture2D") 57 _glGenQueries = LibGLESv2.NewProc("glGenQueries") 58 _glGetError = LibGLESv2.NewProc("glGetError") 59 _glGetRenderbufferParameteri = LibGLESv2.NewProc("glGetRenderbufferParameteri") 60 _glGetFramebufferAttachmentParameteri = LibGLESv2.NewProc("glGetFramebufferAttachmentParameteri") 61 _glGetIntegerv = LibGLESv2.NewProc("glGetIntegerv") 62 _glGetProgramiv = LibGLESv2.NewProc("glGetProgramiv") 63 _glGetProgramInfoLog = LibGLESv2.NewProc("glGetProgramInfoLog") 64 _glGetQueryObjectuiv = LibGLESv2.NewProc("glGetQueryObjectuiv") 65 _glGetShaderiv = LibGLESv2.NewProc("glGetShaderiv") 66 _glGetShaderInfoLog = LibGLESv2.NewProc("glGetShaderInfoLog") 67 _glGetString = LibGLESv2.NewProc("glGetString") 68 _glGetUniformLocation = LibGLESv2.NewProc("glGetUniformLocation") 69 _glInvalidateFramebuffer = LibGLESv2.NewProc("glInvalidateFramebuffer") 70 _glLinkProgram = LibGLESv2.NewProc("glLinkProgram") 71 _glPixelStorei = LibGLESv2.NewProc("glPixelStorei") 72 _glReadPixels = LibGLESv2.NewProc("glReadPixels") 73 _glRenderbufferStorage = LibGLESv2.NewProc("glRenderbufferStorage") 74 _glScissor = LibGLESv2.NewProc("glScissor") 75 _glShaderSource = LibGLESv2.NewProc("glShaderSource") 76 _glTexImage2D = LibGLESv2.NewProc("glTexImage2D") 77 _glTexSubImage2D = LibGLESv2.NewProc("glTexSubImage2D") 78 _glTexParameteri = LibGLESv2.NewProc("glTexParameteri") 79 _glUniform1f = LibGLESv2.NewProc("glUniform1f") 80 _glUniform1i = LibGLESv2.NewProc("glUniform1i") 81 _glUniform2f = LibGLESv2.NewProc("glUniform2f") 82 _glUniform3f = LibGLESv2.NewProc("glUniform3f") 83 _glUniform4f = LibGLESv2.NewProc("glUniform4f") 84 _glUseProgram = LibGLESv2.NewProc("glUseProgram") 85 _glVertexAttribPointer = LibGLESv2.NewProc("glVertexAttribPointer") 86 _glViewport = LibGLESv2.NewProc("glViewport") 87 ) 88 89 type Functions struct { 90 // Query caches. 91 int32s [100]int32 92 } 93 94 func (c *Functions) ActiveTexture(t Enum) { 95 syscall.Syscall(_glActiveTexture.Addr(), 1, uintptr(t), 0, 0) 96 } 97 func (c *Functions) AttachShader(p Program, s Shader) { 98 syscall.Syscall(_glAttachShader.Addr(), 2, uintptr(p.V), uintptr(s.V), 0) 99 } 100 func (f *Functions) BeginQuery(target Enum, query Query) { 101 syscall.Syscall(_glBeginQuery.Addr(), 2, uintptr(target), uintptr(query.V), 0) 102 } 103 func (c *Functions) BindAttribLocation(p Program, a Attrib, name string) { 104 cname := cString(name) 105 c0 := &cname[0] 106 syscall.Syscall(_glBindAttribLocation.Addr(), 3, uintptr(p.V), uintptr(a), uintptr(unsafe.Pointer(c0))) 107 issue34474KeepAlive(c) 108 } 109 func (c *Functions) BindBuffer(target Enum, b Buffer) { 110 syscall.Syscall(_glBindBuffer.Addr(), 2, uintptr(target), uintptr(b.V), 0) 111 } 112 func (c *Functions) BindFramebuffer(target Enum, fb Framebuffer) { 113 syscall.Syscall(_glBindFramebuffer.Addr(), 2, uintptr(target), uintptr(fb.V), 0) 114 } 115 func (c *Functions) BindRenderbuffer(target Enum, rb Renderbuffer) { 116 syscall.Syscall(_glBindRenderbuffer.Addr(), 2, uintptr(target), uintptr(rb.V), 0) 117 } 118 func (c *Functions) BindTexture(target Enum, t Texture) { 119 syscall.Syscall(_glBindTexture.Addr(), 2, uintptr(target), uintptr(t.V), 0) 120 } 121 func (c *Functions) BlendEquation(mode Enum) { 122 syscall.Syscall(_glBlendEquation.Addr(), 1, uintptr(mode), 0, 0) 123 } 124 func (c *Functions) BlendFunc(sfactor, dfactor Enum) { 125 syscall.Syscall(_glBlendFunc.Addr(), 2, uintptr(sfactor), uintptr(dfactor), 0) 126 } 127 func (c *Functions) BufferData(target Enum, src []byte, usage Enum) { 128 if n := len(src); n == 0 { 129 syscall.Syscall6(_glBufferData.Addr(), 4, uintptr(target), 0, 0, uintptr(usage), 0, 0) 130 } else { 131 s0 := &src[0] 132 syscall.Syscall6(_glBufferData.Addr(), 4, uintptr(target), uintptr(n), uintptr(unsafe.Pointer(s0)), uintptr(usage), 0, 0) 133 issue34474KeepAlive(s0) 134 } 135 } 136 func (c *Functions) CheckFramebufferStatus(target Enum) Enum { 137 s, _, _ := syscall.Syscall(_glCheckFramebufferStatus.Addr(), 1, uintptr(target), 0, 0) 138 return Enum(s) 139 } 140 func (c *Functions) Clear(mask Enum) { 141 syscall.Syscall(_glClear.Addr(), 1, uintptr(mask), 0, 0) 142 } 143 func (c *Functions) ClearColor(red, green, blue, alpha float32) { 144 syscall.Syscall6(_glClearColor.Addr(), 4, uintptr(math.Float32bits(red)), uintptr(math.Float32bits(green)), uintptr(math.Float32bits(blue)), uintptr(math.Float32bits(alpha)), 0, 0) 145 } 146 func (c *Functions) ClearDepthf(d float32) { 147 syscall.Syscall(_glClearDepthf.Addr(), 1, uintptr(math.Float32bits(d)), 0, 0) 148 } 149 func (c *Functions) CompileShader(s Shader) { 150 syscall.Syscall(_glCompileShader.Addr(), 1, uintptr(s.V), 0, 0) 151 } 152 func (c *Functions) CreateBuffer() Buffer { 153 var buf uintptr 154 syscall.Syscall(_glGenBuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&buf)), 0) 155 return Buffer{uint(buf)} 156 } 157 func (c *Functions) CreateFramebuffer() Framebuffer { 158 var fb uintptr 159 syscall.Syscall(_glGenFramebuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&fb)), 0) 160 return Framebuffer{uint(fb)} 161 } 162 func (c *Functions) CreateProgram() Program { 163 p, _, _ := syscall.Syscall(_glCreateProgram.Addr(), 0, 0, 0, 0) 164 return Program{uint(p)} 165 } 166 func (f *Functions) CreateQuery() Query { 167 var q uintptr 168 syscall.Syscall(_glGenQueries.Addr(), 2, 1, uintptr(unsafe.Pointer(&q)), 0) 169 return Query{uint(q)} 170 } 171 func (c *Functions) CreateRenderbuffer() Renderbuffer { 172 var rb uintptr 173 syscall.Syscall(_glGenRenderbuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&rb)), 0) 174 return Renderbuffer{uint(rb)} 175 } 176 func (c *Functions) CreateShader(ty Enum) Shader { 177 s, _, _ := syscall.Syscall(_glCreateShader.Addr(), 1, uintptr(ty), 0, 0) 178 return Shader{uint(s)} 179 } 180 func (c *Functions) CreateTexture() Texture { 181 var t uintptr 182 syscall.Syscall(_glGenTextures.Addr(), 2, 1, uintptr(unsafe.Pointer(&t)), 0) 183 return Texture{uint(t)} 184 } 185 func (c *Functions) DeleteBuffer(v Buffer) { 186 syscall.Syscall(_glDeleteBuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&v)), 0) 187 } 188 func (c *Functions) DeleteFramebuffer(v Framebuffer) { 189 syscall.Syscall(_glDeleteFramebuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&v.V)), 0) 190 } 191 func (c *Functions) DeleteProgram(p Program) { 192 syscall.Syscall(_glDeleteProgram.Addr(), 1, uintptr(p.V), 0, 0) 193 } 194 func (f *Functions) DeleteQuery(query Query) { 195 syscall.Syscall(_glDeleteQueries.Addr(), 2, 1, uintptr(unsafe.Pointer(&query.V)), 0) 196 } 197 func (c *Functions) DeleteShader(s Shader) { 198 syscall.Syscall(_glDeleteShader.Addr(), 1, uintptr(s.V), 0, 0) 199 } 200 func (c *Functions) DeleteRenderbuffer(v Renderbuffer) { 201 syscall.Syscall(_glDeleteRenderbuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&v.V)), 0) 202 } 203 func (c *Functions) DeleteTexture(v Texture) { 204 syscall.Syscall(_glDeleteTextures.Addr(), 2, 1, uintptr(unsafe.Pointer(&v.V)), 0) 205 } 206 func (c *Functions) DepthFunc(f Enum) { 207 syscall.Syscall(_glDepthFunc.Addr(), 1, uintptr(f), 0, 0) 208 } 209 func (c *Functions) DepthMask(mask bool) { 210 var m uintptr 211 if mask { 212 m = 1 213 } 214 syscall.Syscall(_glDepthMask.Addr(), 1, m, 0, 0) 215 } 216 func (c *Functions) DisableVertexAttribArray(a Attrib) { 217 syscall.Syscall(_glDisableVertexAttribArray.Addr(), 1, uintptr(a), 0, 0) 218 } 219 func (c *Functions) Disable(cap Enum) { 220 syscall.Syscall(_glDisable.Addr(), 1, uintptr(cap), 0, 0) 221 } 222 func (c *Functions) DrawArrays(mode Enum, first, count int) { 223 syscall.Syscall(_glDrawArrays.Addr(), 3, uintptr(mode), uintptr(first), uintptr(count)) 224 } 225 func (c *Functions) DrawElements(mode Enum, count int, ty Enum, offset int) { 226 syscall.Syscall6(_glDrawElements.Addr(), 4, uintptr(mode), uintptr(count), uintptr(ty), uintptr(offset), 0, 0) 227 } 228 func (c *Functions) Enable(cap Enum) { 229 syscall.Syscall(_glEnable.Addr(), 1, uintptr(cap), 0, 0) 230 } 231 func (c *Functions) EnableVertexAttribArray(a Attrib) { 232 syscall.Syscall(_glEnableVertexAttribArray.Addr(), 1, uintptr(a), 0, 0) 233 } 234 func (f *Functions) EndQuery(target Enum) { 235 syscall.Syscall(_glEndQuery.Addr(), 1, uintptr(target), 0, 0) 236 } 237 func (c *Functions) Finish() { 238 syscall.Syscall(_glFinish.Addr(), 0, 0, 0, 0) 239 } 240 func (c *Functions) FramebufferRenderbuffer(target, attachment, renderbuffertarget Enum, renderbuffer Renderbuffer) { 241 syscall.Syscall6(_glFramebufferRenderbuffer.Addr(), 4, uintptr(target), uintptr(attachment), uintptr(renderbuffertarget), uintptr(renderbuffer.V), 0, 0) 242 } 243 func (c *Functions) FramebufferTexture2D(target, attachment, texTarget Enum, t Texture, level int) { 244 syscall.Syscall6(_glFramebufferTexture2D.Addr(), 5, uintptr(target), uintptr(attachment), uintptr(texTarget), uintptr(t.V), uintptr(level), 0) 245 } 246 func (c *Functions) GetBinding(pname Enum) Object { 247 return Object{uint(c.GetInteger(pname))} 248 } 249 func (c *Functions) GetError() Enum { 250 e, _, _ := syscall.Syscall(_glGetError.Addr(), 0, 0, 0, 0) 251 return Enum(e) 252 } 253 func (c *Functions) GetRenderbufferParameteri(target, pname Enum) int { 254 p, _, _ := syscall.Syscall(_glGetRenderbufferParameteri.Addr(), 2, uintptr(target), uintptr(pname), 0) 255 return int(p) 256 } 257 func (c *Functions) GetFramebufferAttachmentParameteri(target, attachment, pname Enum) int { 258 p, _, _ := syscall.Syscall(_glGetFramebufferAttachmentParameteri.Addr(), 3, uintptr(target), uintptr(attachment), uintptr(pname)) 259 return int(p) 260 } 261 func (c *Functions) GetInteger(pname Enum) int { 262 syscall.Syscall(_glGetIntegerv.Addr(), 2, uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])), 0) 263 return int(c.int32s[0]) 264 } 265 func (c *Functions) GetProgrami(p Program, pname Enum) int { 266 syscall.Syscall(_glGetProgramiv.Addr(), 3, uintptr(p.V), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0]))) 267 return int(c.int32s[0]) 268 } 269 func (c *Functions) GetProgramInfoLog(p Program) string { 270 n := c.GetProgrami(p, INFO_LOG_LENGTH) 271 buf := make([]byte, n) 272 syscall.Syscall6(_glGetProgramInfoLog.Addr(), 4, uintptr(p.V), uintptr(len(buf)), 0, uintptr(unsafe.Pointer(&buf[0])), 0, 0) 273 return string(buf) 274 } 275 func (c *Functions) GetQueryObjectuiv(query Query, pname Enum) uint { 276 syscall.Syscall(_glGetQueryObjectuiv.Addr(), 3, uintptr(query.V), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0]))) 277 return uint(c.int32s[0]) 278 } 279 func (c *Functions) GetShaderi(s Shader, pname Enum) int { 280 syscall.Syscall(_glGetShaderiv.Addr(), 3, uintptr(s.V), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0]))) 281 return int(c.int32s[0]) 282 } 283 func (c *Functions) GetShaderInfoLog(s Shader) string { 284 n := c.GetShaderi(s, INFO_LOG_LENGTH) 285 buf := make([]byte, n) 286 syscall.Syscall6(_glGetShaderInfoLog.Addr(), 4, uintptr(s.V), uintptr(len(buf)), 0, uintptr(unsafe.Pointer(&buf[0])), 0, 0) 287 return string(buf) 288 } 289 func (c *Functions) GetString(pname Enum) string { 290 s, _, _ := syscall.Syscall(_glGetString.Addr(), 1, uintptr(pname), 0, 0) 291 return GoString(SliceOf(s)) 292 } 293 func (c *Functions) GetUniformLocation(p Program, name string) Uniform { 294 cname := cString(name) 295 c0 := &cname[0] 296 u, _, _ := syscall.Syscall(_glGetUniformLocation.Addr(), 2, uintptr(p.V), uintptr(unsafe.Pointer(c0)), 0) 297 issue34474KeepAlive(c) 298 return Uniform{int(u)} 299 } 300 func (c *Functions) InvalidateFramebuffer(target, attachment Enum) { 301 addr := _glInvalidateFramebuffer.Addr() 302 if addr == 0 { 303 // InvalidateFramebuffer is just a hint. Skip it if not supported. 304 return 305 } 306 syscall.Syscall(addr, 3, uintptr(target), 1, uintptr(unsafe.Pointer(&attachment))) 307 } 308 func (c *Functions) LinkProgram(p Program) { 309 syscall.Syscall(_glLinkProgram.Addr(), 1, uintptr(p.V), 0, 0) 310 } 311 func (c *Functions) PixelStorei(pname Enum, param int32) { 312 syscall.Syscall(_glPixelStorei.Addr(), 2, uintptr(pname), uintptr(param), 0) 313 } 314 func (f *Functions) ReadPixels(x, y, width, height int, format, ty Enum, data []byte) { 315 d0 := &data[0] 316 syscall.Syscall6(_glReadPixels.Addr(), uintptr(x), uintptr(y), uintptr(width), uintptr(height), uintptr(format), uintptr(ty), uintptr(unsafe.Pointer(d0))) 317 issue34474KeepAlive(d0) 318 } 319 func (c *Functions) RenderbufferStorage(target, internalformat Enum, width, height int) { 320 syscall.Syscall6(_glRenderbufferStorage.Addr(), 4, uintptr(target), uintptr(internalformat), uintptr(width), uintptr(height), 0, 0) 321 } 322 func (c *Functions) Scissor(x, y, width, height int32) { 323 syscall.Syscall6(_glScissor.Addr(), 4, uintptr(x), uintptr(y), uintptr(width), uintptr(height), 0, 0) 324 } 325 func (c *Functions) ShaderSource(s Shader, src string) { 326 var n uintptr = uintptr(len(src)) 327 psrc := &src 328 syscall.Syscall6(_glShaderSource.Addr(), 4, uintptr(s.V), 1, uintptr(unsafe.Pointer(psrc)), uintptr(unsafe.Pointer(&n)), 0, 0) 329 issue34474KeepAlive(psrc) 330 } 331 func (c *Functions) TexImage2D(target Enum, level int, internalFormat int, width, height int, format, ty Enum, data []byte) { 332 if len(data) == 0 { 333 syscall.Syscall9(_glTexImage2D.Addr(), 9, uintptr(target), uintptr(level), uintptr(internalFormat), uintptr(width), uintptr(height), 0, uintptr(format), uintptr(ty), 0) 334 } else { 335 d0 := &data[0] 336 syscall.Syscall9(_glTexImage2D.Addr(), 9, uintptr(target), uintptr(level), uintptr(internalFormat), uintptr(width), uintptr(height), 0, uintptr(format), uintptr(ty), uintptr(unsafe.Pointer(d0))) 337 issue34474KeepAlive(d0) 338 } 339 } 340 func (c *Functions) TexSubImage2D(target Enum, level int, x, y, width, height int, format, ty Enum, data []byte) { 341 d0 := &data[0] 342 syscall.Syscall9(_glTexSubImage2D.Addr(), 9, uintptr(target), uintptr(level), uintptr(x), uintptr(y), uintptr(width), uintptr(height), uintptr(format), uintptr(ty), uintptr(unsafe.Pointer(d0))) 343 issue34474KeepAlive(d0) 344 } 345 func (c *Functions) TexParameteri(target, pname Enum, param int) { 346 syscall.Syscall(_glTexParameteri.Addr(), 3, uintptr(target), uintptr(pname), uintptr(param)) 347 } 348 func (c *Functions) Uniform1f(dst Uniform, v float32) { 349 syscall.Syscall(_glUniform1f.Addr(), 2, uintptr(dst.V), uintptr(math.Float32bits(v)), 0) 350 } 351 func (c *Functions) Uniform1i(dst Uniform, v int) { 352 syscall.Syscall(_glUniform1i.Addr(), 2, uintptr(dst.V), uintptr(v), 0) 353 } 354 func (c *Functions) Uniform2f(dst Uniform, v0, v1 float32) { 355 syscall.Syscall(_glUniform2f.Addr(), 3, uintptr(dst.V), uintptr(math.Float32bits(v0)), uintptr(math.Float32bits(v1))) 356 } 357 func (c *Functions) Uniform3f(dst Uniform, v0, v1, v2 float32) { 358 syscall.Syscall6(_glUniform3f.Addr(), 4, uintptr(dst.V), uintptr(math.Float32bits(v0)), uintptr(math.Float32bits(v1)), uintptr(math.Float32bits(v2)), 0, 0) 359 } 360 func (c *Functions) Uniform4f(dst Uniform, v0, v1, v2, v3 float32) { 361 syscall.Syscall6(_glUniform4f.Addr(), 5, uintptr(dst.V), uintptr(math.Float32bits(v0)), uintptr(math.Float32bits(v1)), uintptr(math.Float32bits(v2)), uintptr(math.Float32bits(v3)), 0) 362 } 363 func (c *Functions) UseProgram(p Program) { 364 syscall.Syscall(_glUseProgram.Addr(), 1, uintptr(p.V), 0, 0) 365 } 366 func (c *Functions) VertexAttribPointer(dst Attrib, size int, ty Enum, normalized bool, stride, offset int) { 367 var norm uintptr 368 if normalized { 369 norm = 1 370 } 371 syscall.Syscall6(_glVertexAttribPointer.Addr(), 6, uintptr(dst), uintptr(size), uintptr(ty), norm, uintptr(stride), uintptr(offset)) 372 } 373 func (c *Functions) Viewport(x, y, width, height int) { 374 syscall.Syscall6(_glViewport.Addr(), 4, uintptr(x), uintptr(y), uintptr(width), uintptr(height), 0, 0) 375 } 376 377 func cString(s string) []byte { 378 b := make([]byte, len(s)+1) 379 copy(b, s) 380 return b 381 } 382 383 // issue34474KeepAlive calls runtime.KeepAlive as a 384 // workaround for golang.org/issue/34474. 385 func issue34474KeepAlive(v interface{}) { 386 runtime.KeepAlive(v) 387 }