Commit 6fafc260 authored by Gerd Hoffmann's avatar Gerd Hoffmann
Browse files

egl-helpers: add helpers to handle opengl framebuffers 



Add a collection of egl_fb_*() helper functions to manage and use opengl
framebuffers, which is a common pattern in UI code with opengl support.

Signed-off-by: default avatarGerd Hoffmann <kraxel@redhat.com>
Message-id: 20170614084149.31314-2-kraxel@redhat.com
parent 8dfaf23a

include/ui/egl-helpers.h

+15 −0
Original line number Diff line number Diff line
@@ -8,6 +8,21 @@ 
extern EGLDisplay *qemu_egl_display;

extern EGLConfig qemu_egl_config;



typedef struct egl_fb {

    int width;

    int height;

    GLuint texture;

    GLuint framebuffer;

    bool delete_texture;

} egl_fb;



void egl_fb_destroy(egl_fb *fb);

void egl_fb_setup_default(egl_fb *fb, int width, int height);

void egl_fb_create_for_tex(egl_fb *fb, int width, int height, GLuint texture);

void egl_fb_create_new_tex(egl_fb *fb, int width, int height);

void egl_fb_blit(egl_fb *dst, egl_fb *src, bool flip);

void egl_fb_read(void *dst, egl_fb *src);



#ifdef CONFIG_OPENGL_DMABUF



extern int qemu_egl_rn_fd;

ui/egl-helpers.c

+76 −0
Original line number Diff line number Diff line
@@ -24,6 +24,82 @@ 
EGLDisplay *qemu_egl_display;

EGLConfig qemu_egl_config;



/* ------------------------------------------------------------------ */



void egl_fb_destroy(egl_fb *fb)

{

    if (!fb->framebuffer) {

        return;

    }



    if (fb->delete_texture) {

        glDeleteTextures(1, &fb->texture);

        fb->delete_texture = false;

    }

    glDeleteFramebuffers(1, &fb->framebuffer);



    fb->width = 0;

    fb->height = 0;

    fb->texture = 0;

    fb->framebuffer = 0;

}



void egl_fb_setup_default(egl_fb *fb, int width, int height)

{

    fb->width = width;

    fb->height = height;

    fb->framebuffer = 0; /* default framebuffer */

}



void egl_fb_create_for_tex(egl_fb *fb, int width, int height, GLuint texture)

{

    fb->width = width;

    fb->height = height;

    fb->texture = texture;

    if (!fb->framebuffer) {

        glGenFramebuffers(1, &fb->framebuffer);

    }



    glBindFramebuffer(GL_FRAMEBUFFER_EXT, fb->framebuffer);

    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,

                              GL_TEXTURE_2D, fb->texture, 0);

}



void egl_fb_create_new_tex(egl_fb *fb, int width, int height)

{

    GLuint texture;



    glGenTextures(1, &texture);

    glBindTexture(GL_TEXTURE_2D, texture);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height,

                 0, GL_BGRA, GL_UNSIGNED_BYTE, 0);



    egl_fb_create_for_tex(fb, width, height, texture);

    fb->delete_texture = true;

}



void egl_fb_blit(egl_fb *dst, egl_fb *src, bool flip)

{

    GLuint y1, y2;



    glBindFramebuffer(GL_READ_FRAMEBUFFER, src->framebuffer);

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, dst->framebuffer);

    glViewport(0, 0, dst->width, dst->height);

    y1 = flip ? src->height : 0;

    y2 = flip ? 0 : src->height;

    glBlitFramebuffer(0, y1, src->width, y2,

                      0, 0, dst->width, dst->height,

                      GL_COLOR_BUFFER_BIT, GL_LINEAR);

}



void egl_fb_read(void *dst, egl_fb *src)

{

    glBindFramebuffer(GL_READ_FRAMEBUFFER, src->framebuffer);

    glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);

    glReadPixels(0, 0, src->width, src->height,

                 GL_BGRA, GL_UNSIGNED_BYTE, dst);

}



/* ---------------------------------------------------------------------- */



#ifdef CONFIG_OPENGL_DMABUF