Method for generating graphic surfaces to be displayed on a screen, related graphics processor

1. A method for generating graphic surfaces to be displayed on a screen, the method being implemented by a graphics processor and comprising:

generating a first graphic surface to be displayed on the screen;

switching between generating the first graphic surface and generating a second graphic surface;

generating the second graphic surface to be displayed on the screen;

wherein the switching includes:

saving a graphic execution context of the first graphic surface; and

if the generation of the second graphic surface had been interrupted during a preceding switch with the generation of another graphic surface, restoring a graphic execution context of the second graphic surface, the restored context having been saved during said preceding switch; and

wherein each generating step of a respective graphic surface further includes incrementing a respective time counter for each graphic surface, and the switching step further includes saving a value of the time counter of the graphic surface whose graphic execution context is saved.

2. The method according to claim 1 , wherein the graphic surfaces are generated for several distinct software applications, and each respective software application is associated with a set of graphic surface(s) and graphic execution context(s).

3. The method according to claim 2 , wherein said sets are disjoint from one another; each set including a list of attribute(s) for each graphic surface.

4. The method according to claim 2 , wherein a respective overall limit duration is associated with the generation of the set of graphic surface(s) of each software application, and

if the overall limit duration is reached for a respective application during generating a current graphic surface of the set of graphic surface(s) of said respective application, then said generating the current graphic surface is interrupted, and the switching step is done before the generating a subsequent graphic surface of a set of graphic surface(s) of another software application.

5. The method according to claim 1 , wherein a respective unitary limit duration is associated with each generating a respective graphic surface, and

if the unitary limit duration for a respective graphic surface is reached, then the generating the respective graphic surface is interrupted, and the switching step is done before the generating a subsequent graphic surface.

6. The method according to claim 5 , wherein each graphic surface is associated with a respective generating frequency, and the value of the unitary limit duration of a respective graphic surface depends on the generating frequency of said graphic surface.

7. The method according to claim 1 , wherein a maximum refresh time is associated with each respective graphic surface, the value of the maximum refresh time depending on the dimensions of the respective graphic surface, and

if the maximum refresh time is reached for a respective graphic surface during a generating step of said respective graphic surface, then the generating step of the respective graphic surface is interrupted, and the saving of a graphic execution context of said respective graphic surface is not done during the subsequent switching step.

8. The method according to claim 7 , wherein the method further comprises emitting an error signal if the maximum refresh time is reached for a respective graphic surface during a generating step of said respective graphic surface.

9. The method according to claim 1 , wherein the graphic execution context is positioned in an invalid state, for a later reset.

10. The method according to claim 1 , wherein during the switching step, the graphic execution context saved for the respective graphic surface includes at least one information item chosen from the group consisting of:

a rendering library information item;

an information item on a memory location and a memory size of graphic command(s) to be executed for the respective graphic surface; and

an information item of a hardware resource of the graphics processor accessible for the graphic execution of the respective graphic surface.

11. The method according to claim 10 , wherein the rendering library information item is chosen from the group consisting of: a color, a line width, a texture, a texture attribute, a list attribute and an alphanumeric attribute.

12. A graphics processor able to generate graphic surfaces to be displayed on a screen, the graphics processor comprising:

a generating module configured to generate respective graphic surfaces to be displayed on the screen;

a switching module configured to switch between generating a first graphic surface and generating a second graphic surface;

wherein the switching module is configured to save a graphic execution context of the first graphic surface; and if the generation of the second graphic surface had been interrupted during a preceding switch with the generation of another graphic surface, then configured to restore a graphic execution context of the second graphic surface, the restored context having been saved during said preceding switch; and

wherein each generating step of a respective graphic surface further includes incrementing a respective time counter for each graphic surface, and the switching step further includes saving a value of the time counter of the graphic surface whose graphic execution context is saved.