func New() (*Renderer, error) {
r := &Renderer{
RenderExec: make(chan func() bool, 1024),
LoaderExec: make(chan func(), 1024),
renderComplete: make(chan struct{}, 8),
wantFree: make(chan struct{}, 1),
clock: clock.New(),
}
// MSAA is enabled by default.
r.msaa.enabled = true
// Initialize r.render now.
r.render = gl.New()
r.render.SetBatching(false)
if !r.render.AtLeastVersion(2, 0) {
return nil, ErrInvalidVersion
}
// Initialize r.loader now.
r.loader = gl.New()
r.loader.SetBatching(false)
// Note: we don't need r.ctx.Lock() here because no other goroutines
// can be using r.ctx yet since we haven't returned from New().
// Find the renderer's precision.
var redBits, greenBits, blueBits, alphaBits, depthBits, stencilBits int32
r.render.GetIntegerv(gl.RED_BITS, &redBits)
r.render.GetIntegerv(gl.GREEN_BITS, &greenBits)
r.render.GetIntegerv(gl.BLUE_BITS, &blueBits)
r.render.GetIntegerv(gl.ALPHA_BITS, &alphaBits)
r.render.GetIntegerv(gl.DEPTH_BITS, &depthBits)
r.render.GetIntegerv(gl.STENCIL_BITS, &stencilBits)
r.render.Execute()
r.precision.RedBits = uint8(redBits)
r.precision.GreenBits = uint8(greenBits)
r.precision.BlueBits = uint8(blueBits)
r.precision.AlphaBits = uint8(alphaBits)
r.precision.DepthBits = uint8(depthBits)
r.precision.StencilBits = uint8(stencilBits)
// Query whether we have the GL_ARB_framebuffer_object.
r.glArbFramebufferObject = r.render.Extension("GL_ARB_framebuffer_object")
// Query whether we have the GL_ARB_occlusion_query.
r.glArbOcclusionQuery = r.render.Extension("GL_ARB_occlusion_query")
// Query whether we have the GL_ARB_multisample extension.
r.glArbMultisample = r.render.Extension("GL_ARB_multisample")
if r.glArbMultisample {
// Query the number of samples and sample buffers we have, if any.
r.render.GetIntegerv(gl.SAMPLES, &r.samples)
r.render.GetIntegerv(gl.SAMPLE_BUFFERS, &r.sampleBuffers)
r.render.Execute() // Needed because glGetIntegerv must execute now.
r.precision.Samples = int(r.samples)
}
// Store GPU info.
var maxTextureSize, maxVaryingFloats, maxVertexInputs, maxFragmentInputs, occlusionQueryBits int32
r.render.GetIntegerv(gl.MAX_TEXTURE_SIZE, &maxTextureSize)
r.render.GetIntegerv(gl.MAX_VARYING_FLOATS, &maxVaryingFloats)
r.render.GetIntegerv(gl.MAX_VERTEX_UNIFORM_COMPONENTS, &maxVertexInputs)
r.render.GetIntegerv(gl.MAX_FRAGMENT_UNIFORM_COMPONENTS, &maxFragmentInputs)
if r.glArbOcclusionQuery {
r.render.GetQueryiv(gl.SAMPLES_PASSED, gl.QUERY_COUNTER_BITS, &occlusionQueryBits)
}
r.render.Execute()
r.gpuInfo.MaxTextureSize = int(maxTextureSize)
r.gpuInfo.GLSLMaxVaryingFloats = int(maxVaryingFloats)
r.gpuInfo.GLSLMaxVertexInputs = int(maxVertexInputs)
r.gpuInfo.GLSLMaxFragmentInputs = int(maxFragmentInputs)
r.gpuInfo.GLExtensions = r.render.Extensions()
r.gpuInfo.AlphaToCoverage = r.glArbMultisample && r.samples > 0 && r.sampleBuffers > 0
r.gpuInfo.Name = gl.String(r.render.GetString(gl.RENDERER))
r.gpuInfo.Vendor = gl.String(r.render.GetString(gl.VENDOR))
r.gpuInfo.GLMajor, r.gpuInfo.GLMinor, _ = r.render.Version()
r.gpuInfo.GLSLMajor, r.gpuInfo.GLSLMinor, _ = r.render.ShaderVersion()
r.gpuInfo.OcclusionQuery = r.glArbOcclusionQuery && occlusionQueryBits > 0
r.gpuInfo.OcclusionQueryBits = int(occlusionQueryBits)
// Grab the current renderer bounds (opengl viewport).
var viewport [4]int32
r.render.GetIntegerv(gl.VIEWPORT, &viewport[0])
r.render.Execute()
r.bounds.rect = image.Rect(0, 0, int(viewport[2]), int(viewport[3]))
// Update scissor rectangle.
r.stateScissor(r.bounds.rect)
// Grab the number of texture compression formats.
var numFormats int32
r.render.GetIntegerv(gl.NUM_COMPRESSED_TEXTURE_FORMATS, &numFormats)
r.render.Execute() // Needed because glGetIntegerv must execute now.
// Store the slice of texture compression formats.
if numFormats > 0 {
r.compressedTextureFormats = make([]int32, numFormats)
r.render.GetIntegerv(gl.COMPRESSED_TEXTURE_FORMATS, &r.compressedTextureFormats[0])
r.render.Execute() // Needed because glGetIntegerv must execute now.
}
return r, nil
}
// Nil returns a renderer that does not actually render anything.
func Nil() Renderer {
r := new(nilRenderer)
r.msaa.enabled = true
r.clock = clock.New()
return r
}