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Gecko:Layers: Difference between revisions
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== Bas == | == Bas == | ||
// The controlling class that controls the composition of frames. This | |||
// lives on a rectangular area on the client's screen, and controls the | |||
// composition of all layers on the compositor. This runs its own thread | |||
// internally from which all OpenGL/D3D operations are executed. All re- | |||
// scheduling of drawing and invalidations are run based on operations | |||
// executed on the compositor and its layers. | |||
class Compositor | |||
{ | |||
// Create a layer that can be used to render to, the size here | |||
// describes the size in pixels. The format the format of the data, | |||
// This can be RGB, RGBA, YUV. The compositor will know what to do | |||
// with these layers, and how to render them properly. When the last | |||
// reference to the layer dies there will be only one left, and it's | |||
// ready to be destroyed. Type can be one of hardware or managed. | |||
// Only managed layers can be drawn to directly from software. | |||
// Any created layer can contain other layers inside, places anywhere | |||
// on its surface. | |||
Layer *CreateLayer(size, format, type); | |||
} | |||
// These are operations that can be executed on all layers. | |||
class ILayer | |||
{ | |||
// Color by which the layers pixels are multiplied, | |||
// This contains an alpha value so opacity can implicitly | |||
// be controlled. | |||
SetColor(color); | |||
// Sets an affine transformation to place the layer with. | |||
SetTransform(matrix); | |||
// Add a layer to this layer. This layer may be blitted onto | |||
// this layer's hardware surface. | |||
AddLayer(ILayer); | |||
// Optional pixel shader program to run on this layer. This can be | |||
// used to apply a variety of effects to the layer when rendered. | |||
SetShader(shader); | |||
} | |||
// Layers exposing this interface allow access to the surface. Double | |||
// buffered, this means that if it's currently being drawn to the compositor | |||
// will simply draw the texture. This will ensure rendering of the compositor | |||
// area doesn't stall waiting on an expensive software render. | |||
class ILockableLayer | |||
{ | |||
// Lock the surface of this layer. Returns a gfxContext to draw to. | |||
gfxContext *Lock(); | |||
// Unlock the surface, this means we're done. And will signal the | |||
// compositor to update the associated texture and redraw. | |||
Unlock(); | |||
} | |||
// Layers exposing this interface can have their hardware surface accessed, | |||
// which can then be used as a render target for other accelerated parts of | |||
// the code. | |||
class IHardwareLayer | |||
{ | |||
// Return hardware surface in whatever structure we pick. Might need | |||
// locking/unlocking logic. | |||
HardwareSurface *Surface(); | |||
} | |||