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# SDL-DREAMHAL Version 1.0 based on SDL1.2.13
* DREAMCAST hardware +opengl SDL FAST BLIT SPEED CUSTOM
Simple DirectMedia Layer is a cross-platform multimedia library designed to provide low level access to audio, keyboard, mouse, joystick, 3D hardware via OpenGL, and 2D video framebuffer. 
*New features
 UPGRADED blitspeed using moops dreamhal sh4 asm memcpy and memset bult in.
  Now using GLDC  https://gitlab.com/simulant/GLdc
	OpenGL (Open Graphics Library) is a standard specification defining a cross-language cross-platform API for writing applications that produce 2D and 3D computer graphics. The    interface consists of over 250 different function calls which can be used to draw complex three-dimensional scenes from simple primitives.	
	Kazade's Dreamcast OpenGL is a more compatible OpenGL (v1.2) library GLDC:	
	Full KallistiOS and SDL integration.
	Texture color and size conversions.
	Two texture internal color mode supported: RGB5551 and RGB4444.
	
	- Ported precompiled libraries and headers needed to compile all examples

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Credit Chui for doing all this work so i could upgrade it and improve it for the new GLDC and Dreamhal math routines and functions 


# Old version
http://chui.dcemu.co.uk/sdl.html

	- VIDEO
 Before SDL_Init call, you can choose SDL video driver for Dreamcast. The following values are valid.

* SDL_DC_DMA_VIDEO (default)
	Use DMA video drive. It is the fastest video driver using double buffer 
	since every graphic access uses RAM and SDL_Flip function sends data to VRAM using DMA.
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- SDL_DC_TEXTURED_VIDEO
	Use Textured video driver. If you want to use a virtual resolution (no 640x480, 320x240, ... ), you can use this driver for scaling using hardware texture. PVR textures is always 2^n (128x128, 256x128, 512x256, ... ) and these resolutions are real SDL_Surface resolutions.
Using SDL_FULLSCREEN flag only 2^n resolution are allowed, but if you do not use this flag it will be automatically fit to SDL_SetVideoMode resolution. See SDL_DC_SetWindow for manual fit.
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- SDL_DC_DIRECT_VIDEO
- ----------------------------
	Use Direct buffer video driver. Maybe faster than DMA driver if you do not use double buffer.
	SDL_DC_SetWindow(int width, int height)
	Only for textured video driver and must be called after SDL_SetVideoMode,
	this function allow setting the visible area (hardware scaled). If you open a 512x256 texture resolution, 
	only smaller virtual resolution is allowed.
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* SDL_DC_VerticalWait(SDL_bool value)
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Enable/disable wait for vertical retrace before blitting to PVR hardware.		
	
* SDL_DC_ShowAskHz(SDL_bool value)
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Enable/disable ask for 50/60Hz (only for PAL Dreamcasts) video.		
	
* SDL_DC_Default60Hz(SDL_bool value)
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True for 60Hz default display (only for PAL Dreamcasts).

* SDL_DC_MapKey(int joy, SDL_DC_button button, SDLKey key)

Map a Dreamcast button to SDLKey. First parameter is number of Dreamcast joystick port (0,1,2 or 3). The following table shows valid values for second parameter and default values for third parameter.


Opengl Dreamhal+GLDC running on Dreamcast hardware
https://streamable.com/55982r
https://streamable.com/kvk4ez
https://streamable.com/5k8lsk