// Arrays mode uses vertex arrays which involves gl*Pointer calls and
// directly passing in the vertex data on every render pass. This is slower
// than using VBO's, because the data has to be uploaded to the GPU on every
// render pass, but it is useful for older systems where glBufferData is
// not available.
func (mb *MeshBuffer) renderArrays(mode gl.GLenum, m Mesh, pa, ca, na, ta, ia *Attr) {
ps, pc := m[mbPositionKey][0], m[mbPositionKey][1]
is, ic := m[mbIndexKey][0], m[mbIndexKey][1]
cc := m[mbColorKey][1]
nc := m[mbNormalKey][1]
tc := m[mbTexCoordKey][1]
gl.PushClientAttrib(gl.CLIENT_VERTEX_ARRAY_BIT)
defer gl.PopClientAttrib()
if pc > 0 {
gl.EnableClientState(gl.VERTEX_ARRAY)
defer gl.DisableClientState(gl.VERTEX_ARRAY)
gl.VertexPointer(pa.size, pa.typ, 0, pa.ptr(0))
}
if cc > 0 {
gl.EnableClientState(gl.COLOR_ARRAY)
defer gl.DisableClientState(gl.COLOR_ARRAY)
gl.ColorPointer(ca.size, ca.typ, 0, ca.ptr(0))
}
if nc > 0 {
gl.EnableClientState(gl.NORMAL_ARRAY)
defer gl.DisableClientState(gl.NORMAL_ARRAY)
gl.NormalPointer(na.typ, 0, na.ptr(0))
}
if tc > 0 {
gl.EnableClientState(gl.TEXTURE_COORD_ARRAY)
defer gl.DisableClientState(gl.TEXTURE_COORD_ARRAY)
gl.TexCoordPointer(ta.size, ta.typ, 0, ta.ptr(0))
}
if ic > 0 {
gl.EnableClientState(gl.INDEX_ARRAY)
defer gl.DisableClientState(gl.INDEX_ARRAY)
gl.IndexPointer(ia.typ, 0, ia.ptr(0))
gl.DrawElements(mode, ic, ia.typ, ia.ptr(is*ia.size))
} else {
gl.DrawArrays(mode, ps, pc)
}
}
// renderBuffered uses VBO's. This is the preferred mode for systems
// where shader support is not present or deemed necessary.
func (mb *MeshBuffer) renderBuffered(mode gl.GLenum, m Mesh, pa, ca, na, ta, ia *Attr) {
ps, pc := m[mbPositionKey][0], m[mbPositionKey][1]
is, ic := m[mbIndexKey][0], m[mbIndexKey][1]
cc := m[mbColorKey][1]
nc := m[mbNormalKey][1]
tc := m[mbTexCoordKey][1]
if pc > 0 {
gl.EnableClientState(gl.VERTEX_ARRAY)
defer gl.DisableClientState(gl.VERTEX_ARRAY)
pa.bind()
if pa.Invalid() {
pa.buffer()
}
gl.VertexPointer(pa.size, pa.typ, 0, uintptr(0))
pa.unbind()
}
if cc > 0 {
gl.EnableClientState(gl.COLOR_ARRAY)
defer gl.DisableClientState(gl.COLOR_ARRAY)
ca.bind()
if ca.Invalid() {
ca.buffer()
}
gl.ColorPointer(ca.size, ca.typ, 0, uintptr(0))
ca.unbind()
}
if nc > 0 {
gl.EnableClientState(gl.NORMAL_ARRAY)
defer gl.DisableClientState(gl.NORMAL_ARRAY)
na.bind()
if na.Invalid() {
na.buffer()
}
gl.NormalPointer(na.typ, 0, uintptr(0))
na.unbind()
}
if tc > 0 {
gl.EnableClientState(gl.TEXTURE_COORD_ARRAY)
defer gl.DisableClientState(gl.TEXTURE_COORD_ARRAY)
ta.bind()
if ta.Invalid() {
ta.buffer()
}
gl.TexCoordPointer(ta.size, ta.typ, 0, uintptr(0))
ta.unbind()
}
if ic > 0 {
ia.bind()
if ia.Invalid() {
ia.buffer()
}
gl.PushClientAttrib(gl.CLIENT_VERTEX_ARRAY_BIT)
gl.DrawElements(mode, ic, ia.typ, uintptr(is*ia.stride))
gl.PopClientAttrib()
ia.unbind()
} else {
pa.bind()
gl.PushClientAttrib(gl.CLIENT_VERTEX_ARRAY_BIT)
gl.DrawArrays(mode, ps, pc)
gl.PopClientAttrib()
pa.unbind()
}
}
func (r *RenderTarget) Render(verts []Vertex, primType PrimitiveType, states RenderStates) {
// Nothing to draw?
if len(verts) == 0 {
return
}
// First set the persistent OpenGL states if it's the very first call
if !r.glStatesSet {
r.resetGlStates()
}
// Check if the vertex count is low enough so that we can pre-transform them
useVertexCache := len(verts) <= vertexCacheSize
if useVertexCache {
// Pre-transform the vertices and store them into the vertex cache
for i := 0; i < len(verts); i++ {
r.vpCache[i] = states.Transform.TransformPoint(verts[i].Pos)
r.vcCache[i] = verts[i].Color
r.vtCache[i] = verts[i].TexCoords
}
// Since vertices are transformed, we must use an identity transform to render them
if !r.useVertexCache {
r.applyTransform(IdentityTransform())
}
} else {
r.applyTransform(states.Transform)
}
// Apply the view
if r.viewChanged {
r.applyCurrentView()
}
// Apply the blend mode
if states.BlendMode != r.lastBlendMode {
r.applyBlendMode(states.BlendMode)
}
// Apply the texture
var textureId uint64
if states.Texture != nil {
textureId = states.Texture.cacheId
}
if textureId != r.lastTextureId {
r.applyTexture(states.Texture)
}
// Apply the shader
// TODO
/*if states.shader {
applyShader(states.shader);
}*/
// #########################################
if !useVertexCache {
// Find the OpenGL primitive type
modes := [...]gl.GLenum{gl.POINTS, gl.LINES, gl.LINE_STRIP, gl.TRIANGLES,
gl.TRIANGLE_STRIP, gl.TRIANGLE_FAN, gl.QUADS}
mode := modes[primType]
gl.Begin(mode)
for i, _ := range verts {
gl.TexCoord2f(verts[i].TexCoords.X, verts[i].TexCoords.Y)
gl.Color4f(float32(verts[i].Color.R)/255, float32(verts[i].Color.G)/255,
float32(verts[i].Color.B)/255, float32(verts[i].Color.A)/255)
gl.Vertex2f(verts[i].Pos.X, verts[i].Pos.Y)
}
gl.End()
}
// #########################################
// Setup the pointers to the vertices' components
// ... and if we already used it previously, we don't need to set the pointers again
if useVertexCache {
if !r.useVertexCache {
gl.VertexPointer(2, gl.FLOAT, 0, r.vpCache[:])
gl.ColorPointer(4, gl.UNSIGNED_BYTE, 0, r.vcCache[:])
gl.TexCoordPointer(2, gl.FLOAT, 0, r.vtCache[:])
}
// Find the OpenGL primitive type
modes := [...]gl.GLenum{gl.POINTS, gl.LINES, gl.LINE_STRIP, gl.TRIANGLES,
gl.TRIANGLE_STRIP, gl.TRIANGLE_FAN, gl.QUADS}
mode := modes[primType]
// Draw the primitives
gl.DrawArrays(mode, 0, len(verts))
}
// Unbind the shader, if any
// TODO
/*if (states.shader) {
r.applyShader(nil)
}*/
// Update the cache
r.useVertexCache = useVertexCache
}