gl.c File Reference

#include "../../SDL_internal.h"
#include "sdl_qnx.h"

Include dependency graph for gl.c:

Go to the source code of this file.

Functions
static int	chooseFormat (EGLConfig egl_conf)
int	glGetConfig (EGLConfig *pconf, int *pformat)
int	glLoadLibrary (_THIS, const char *name)
void *	glGetProcAddress (_THIS, const char *proc)
SDL_GLContext	glCreateContext (_THIS, SDL_Window *window)
int	glSetSwapInterval (_THIS, int interval)
int	glSwapWindow (_THIS, SDL_Window *window)
int	glMakeCurrent (_THIS, SDL_Window *window, SDL_GLContext context)
void	glDeleteContext (_THIS, SDL_GLContext context)
void	glUnloadLibrary (_THIS)

Variables
static EGLDisplay	egl_disp

Function Documentation

chooseFormat()

static int chooseFormat ( EGLConfig  egl_conf )

static

Detertmines the pixel format to use based on the current display and EGL configuration.

Parameters

egl_conf

EGL configuration to use

Returns

A SCREEN_FORMAT* constant for the pixel format to use

Definition at line 34 of file gl.c.

{
    EGLint buffer_bit_depth;
    EGLint alpha_bit_depth;
 
    eglGetConfigAttrib(egl_disp, egl_conf, EGL_BUFFER_SIZE, &buffer_bit_depth);
    eglGetConfigAttrib(egl_disp, egl_conf, EGL_ALPHA_SIZE, &alpha_bit_depth);
 
    switch (buffer_bit_depth) {
        case 32:
            return SCREEN_FORMAT_RGBX8888;
        case 24:
            return SCREEN_FORMAT_RGB888;
        case 16:
            switch (alpha_bit_depth) {
                case 4:
                    return SCREEN_FORMAT_RGBX4444;
                case 1:
                    return SCREEN_FORMAT_RGBA5551;
                default:
                    return SCREEN_FORMAT_RGB565;
            }
        default:
            return 0;
    }
}

References EGL_ALPHA_SIZE, EGL_BUFFER_SIZE, egl_disp, and eglGetConfigAttrib().

Referenced by glGetConfig().

glCreateContext()

SDL_GLContext glCreateContext	(	_THIS	,
		SDL_Window *	window
	)

Associates the given window with the necessary EGL structures for drawing and displaying content.

Parameters

_THIS
window	The SDL window to create the context for

Returns

A pointer to the created context, if successful, NULL on error

Definition at line 171 of file gl.c.

{
    window_impl_t   *impl = (window_impl_t *)window->driverdata;
    EGLContext      context;
    EGLSurface      surface;
 
    struct {
        EGLint client_version[2];
        EGLint none;
    } egl_ctx_attr = {
        .client_version = { EGL_CONTEXT_CLIENT_VERSION, 2 },
        .none = EGL_NONE
    };
 
    struct {
        EGLint render_buffer[2];
        EGLint none;
    } egl_surf_attr = {
        .render_buffer = { EGL_RENDER_BUFFER, EGL_BACK_BUFFER },
        .none = EGL_NONE
    };
 
    context = eglCreateContext(egl_disp, impl->conf, EGL_NO_CONTEXT,
                               (EGLint *)&egl_ctx_attr);
    if (context == EGL_NO_CONTEXT) {
        return NULL;
    }
 
    surface = eglCreateWindowSurface(egl_disp, impl->conf, impl->window,
                                     (EGLint *)&egl_surf_attr);
    if (surface == EGL_NO_SURFACE) {
        return NULL;
    }
 
    eglMakeCurrent(egl_disp, surface, surface, context);
 
    impl->surface = surface;
    return context;
}

References context.

Referenced by createDevice().

glDeleteContext()

void glDeleteContext	(	_THIS	,
		SDL_GLContext	context
	)

Destroys a context.

Parameters

_THIS
context	The context to destroy

Definition at line 272 of file gl.c.

{
    eglDestroyContext(egl_disp, context);
}

References context, egl_disp, and eglDestroyContext().

Referenced by createDevice().

glGetConfig()

int glGetConfig	(	EGLConfig *	pconf,
		int *	pformat
	)

Enumerates the supported EGL configurations and chooses a suitable one.

Parameters

[out]	pconf	The chosen configuration
[out]	pformat	The chosen pixel format

Returns

0 if successful, -1 on error

Definition at line 68 of file gl.c.

{
    EGLConfig egl_conf = (EGLConfig)0;
    EGLConfig *egl_configs;
    EGLint egl_num_configs;
    EGLint val;
    EGLBoolean rc;
    EGLint i;
 
    // Determine the numbfer of configurations.
    rc = eglGetConfigs(egl_disp, NULL, 0, &egl_num_configs);
    if (rc != EGL_TRUE) {
        return -1;
    }
 
    if (egl_num_configs == 0) {
        return -1;
    }
 
    // Allocate enough memory for all configurations.
    egl_configs = malloc(egl_num_configs * sizeof(*egl_configs));
    if (egl_configs == NULL) {
        return -1;
    }
 
    // Get the list of configurations.
    rc = eglGetConfigs(egl_disp, egl_configs, egl_num_configs,
                       &egl_num_configs);
    if (rc != EGL_TRUE) {
        free(egl_configs);
        return -1;
    }
 
    // Find a good configuration.
    for (i = 0; i < egl_num_configs; i++) {
        eglGetConfigAttrib(egl_disp, egl_configs[i], EGL_SURFACE_TYPE, &val);
        if (!(val & EGL_WINDOW_BIT)) {
            continue;
        }
 
        eglGetConfigAttrib(egl_disp, egl_configs[i], EGL_RENDERABLE_TYPE, &val);
        if (!(val & EGL_OPENGL_ES2_BIT)) {
            continue;
        }
 
        eglGetConfigAttrib(egl_disp, egl_configs[i], EGL_DEPTH_SIZE, &val);
        if (val == 0) {
            continue;
        }
 
        egl_conf = egl_configs[i];
        break;
    }
 
    free(egl_configs);
    *pconf = egl_conf;
    *pformat = chooseFormat(egl_conf);
 
    return 0;
}

References chooseFormat(), EGL_DEPTH_SIZE, egl_disp, EGL_OPENGL_ES2_BIT, EGL_RENDERABLE_TYPE, EGL_SURFACE_TYPE, EGL_TRUE, EGL_WINDOW_BIT, eglGetConfigAttrib(), eglGetConfigs(), free, i, malloc, and NULL.

Referenced by createWindow().

glGetProcAddress()

void* glGetProcAddress	(	_THIS	,
		const char *	proc
	)

Finds the address of an EGL extension function.

Parameters

proc	Function name

Returns

Function address

Definition at line 158 of file gl.c.

{
    return eglGetProcAddress(proc);
}

References eglGetProcAddress().

Referenced by createDevice().

glLoadLibrary()

int glLoadLibrary	(	_THIS	,
		const char *	name
	)

Initializes the EGL library.

Parameters

_THIS
name	unused

Returns

0 if successful, -1 on error

Definition at line 136 of file gl.c.

{
    EGLNativeDisplayType    disp_id = EGL_DEFAULT_DISPLAY;
 
    egl_disp = eglGetDisplay(disp_id);
    if (egl_disp == EGL_NO_DISPLAY) {
        return -1;
    }
 
    if (eglInitialize(egl_disp, NULL, NULL) == EGL_FALSE) {
        return -1;
    }
 
    return 0;
}

References EGL_DEFAULT_DISPLAY, egl_disp, EGL_FALSE, EGL_NO_DISPLAY, eglGetDisplay(), eglInitialize(), and NULL.

Referenced by createDevice().

glMakeCurrent()

int glMakeCurrent	(	_THIS	,
		SDL_Window *	window,
		SDL_GLContext	context
	)

Makes the given context the current one for drawing operations.

Parameters

_THIS
window	SDL window associated with the context (maybe NULL)
context	The context to activate

Returns

0 if successful, -1 on error

Definition at line 249 of file gl.c.

{
    window_impl_t   *impl;
    EGLSurface      surface = NULL;
 
    if (window) {
        impl = (window_impl_t *)window->driverdata;
        surface = impl->surface;
    }
 
    if (eglMakeCurrent(egl_disp, surface, surface, context) != EGL_TRUE) {
        return -1;
    }
 
    return 0;
}

References context, egl_disp, EGL_TRUE, eglMakeCurrent(), NULL, and window_impl_t::surface.

Referenced by createDevice().

glSetSwapInterval()

int glSetSwapInterval	(	_THIS	,
		int	interval
	)

Sets a new value for the number of frames to display before swapping buffers.

Parameters

_THIS
interval	New interval value

Returns

0 if successful, -1 on error

Definition at line 218 of file gl.c.

{
    if (eglSwapInterval(egl_disp, interval) != EGL_TRUE) {
        return -1;
    }
 
    return 0;
}

References egl_disp, EGL_TRUE, and eglSwapInterval().

Referenced by createDevice().

glSwapWindow()

int glSwapWindow	(	_THIS	,
		SDL_Window *	window
	)

Swaps the EGL buffers associated with the given window

Parameters

_THIS
window	Window to swap buffers for

Returns

0 if successful, -1 on error

Definition at line 234 of file gl.c.

{
    /* !!! FIXME: should we migrate this all over to use SDL_egl.c? */
    window_impl_t   *impl = (window_impl_t *)window->driverdata;
    return eglSwapBuffers(egl_disp, impl->surface) == EGL_TRUE ? 0 : -1;
}

References egl_disp, EGL_TRUE, eglSwapBuffers(), and window_impl_t::surface.

Referenced by createDevice().

glUnloadLibrary()

void glUnloadLibrary

(

_THIS

)

Terminates access to the EGL library.

Parameters

_THIS

Definition at line 282 of file gl.c.

{
    eglTerminate(egl_disp);
}

References egl_disp, and eglTerminate().

Referenced by createDevice().

Variable Documentation

egl_disp

EGLDisplay egl_disp

static

Definition at line 25 of file gl.c.

Referenced by chooseFormat(), glDeleteContext(), glGetConfig(), glLoadLibrary(), glMakeCurrent(), glSetSwapInterval(), glSwapWindow(), and glUnloadLibrary().