gpu/internal/opengl,internal: move sRGB emulation to OpenGL driver

There is only one driver but several backends (EGL, WebGL).

Signed-off-by: Elias Naur <mail@eliasnaur.com>

internal/gl/gl.go

@@ -10,6 +10,7 @@ type (
 const (
 	ALL_BARRIER_BITS                      = 0xffffffff
 	ARRAY_BUFFER                          = 0x8892
+	BACK                                  = 0x0405
 	BLEND                                 = 0xbe2
 	CLAMP_TO_EDGE                         = 0x812f
 	COLOR_ATTACHMENT0                     = 0x8ce0

internal/gl/gl_unix.go

@@ -436,6 +436,15 @@ func (f *Functions) GetFramebufferAttachmentParameteri(target, attachment, pname
 	return int(f.ints[0])
 }
 
+func (f *Functions) GetInteger4(pname Enum) [4]int {
+	C.glGetIntegerv(C.GLenum(pname), &f.ints[0])
+	var r [4]int
+	for i := range r {
+		r[i] = int(f.ints[i])
+	}
+	return r
+}
+
 func (f *Functions) GetInteger(pname Enum) int {
 	C.glGetIntegerv(C.GLenum(pname), &f.ints[0])
 	return int(f.ints[0])

internal/gl/gl_windows.go

@@ -292,6 +292,14 @@ func (c *Functions) GetFramebufferAttachmentParameteri(target, attachment, pname
 	p, _, _ := syscall.Syscall(_glGetFramebufferAttachmentParameteri.Addr(), 3, uintptr(target), uintptr(attachment), uintptr(pname))
 	return int(p)
 }
+func (c *Functions) GetInteger4(pname Enum) [4]int {
+	syscall.Syscall(_glGetIntegerv.Addr(), 2, uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])), 0)
+	var r [4]int
+	for i := range r {
+		r[i] = int(c.int32s[i])
+	}
+	return r
+}
 func (c *Functions) GetInteger(pname Enum) int {
 	syscall.Syscall(_glGetIntegerv.Addr(), 2, uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])), 0)
 	return int(c.int32s[0])

internal/gl/types.go

@@ -14,6 +14,10 @@ type (
 	Object       struct{ V uint }
 )
 
+func (u Framebuffer) Valid() bool {
+	return u.V != 0
+}
+
 func (u Uniform) Valid() bool {
 	return u.V != -1
 }

internal/gl/types_js.go

@@ -16,6 +16,10 @@ type (
 	Object       js.Value
 )
 
+func (f Framebuffer) Valid() bool {
+	return !js.Value(f).IsUndefined() && !js.Value(f).IsNull()
+}
+
 func (p Program) Valid() bool {
 	return !js.Value(p).IsUndefined() && !js.Value(p).IsNull()
 }