Skia on the Raspberry Pi

main.cpp

#include <iostream>
#include <assert.h>
#include <stdio.h>
#include <cstdio>

#include <bcm_host.h>
#include <EGL/egl.h>
#include <EGL/eglext.h>
#include <GLES2/gl2.h>
#include <GLES2/gl2ext.h>

#include "GrContext.h"
#include "gl/GrGLInterface.h"
#include "SkData.h"
#include "SkImage.h"
#include "SkStream.h"
#include "SkSurface.h"
#include "SkCanvas.h"
#include "SkPaint.h"

typedef struct {
   uint32_t screen_width;
   uint32_t screen_height;
   EGLDisplay display;
   EGLSurface surface;
   EGLContext context;
} CUBE_STATE_T;

static CUBE_STATE_T _state, *state=&_state;

static void init_ogl(CUBE_STATE_T *state) {
   int32_t success = 0;
   EGLBoolean result;
   EGLint num_config;

   static EGL_DISPMANX_WINDOW_T nativewindow;

   DISPMANX_ELEMENT_HANDLE_T dispman_element;
   DISPMANX_DISPLAY_HANDLE_T dispman_display;
   DISPMANX_UPDATE_HANDLE_T dispman_update;
   VC_RECT_T dst_rect;
   VC_RECT_T src_rect;

   static const EGLint attribute_list[] = {
      EGL_RED_SIZE, 8,
      EGL_GREEN_SIZE, 8,
      EGL_BLUE_SIZE, 8,
      EGL_ALPHA_SIZE, 8,
      EGL_DEPTH_SIZE, 0,
      EGL_STENCIL_SIZE, 8,
      EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
      EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
      EGL_NONE
   };

   const EGLint context_attrib_list[] = {
           EGL_CONTEXT_CLIENT_VERSION, 2,
           EGL_NONE
   };

   EGLConfig config;

   state->display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
   assert(state->display!=EGL_NO_DISPLAY);

   result = eglInitialize(state->display, NULL, NULL);
   assert(EGL_FALSE != result);

   result = eglChooseConfig(state->display, attribute_list, &config, 1, &num_config);
   assert(EGL_FALSE != result);

   result = eglBindAPI(EGL_OPENGL_ES_API);
   assert(EGL_FALSE != result);

   state->context = eglCreateContext(state->display, config, EGL_NO_CONTEXT, context_attrib_list);
   assert(state->context!=EGL_NO_CONTEXT);

   success = graphics_get_display_size(0, &state->screen_width, &state->screen_height);
   assert( success >= 0 );

   dst_rect.x = 0;
   dst_rect.y = 0;
   dst_rect.width = state->screen_width;
   dst_rect.height = state->screen_height;

   src_rect.x = 0;
   src_rect.y = 0;
   src_rect.width = state->screen_width << 16;
   src_rect.height = state->screen_height << 16;

   dispman_display = vc_dispmanx_display_open( 0 /* LCD */);
   dispman_update = vc_dispmanx_update_start( 0 );

   dispman_element = vc_dispmanx_element_add ( dispman_update, dispman_display, 0, &dst_rect, 0, &src_rect, DISPMANX_PROTECTION_NONE, 0, 0, DISPMANX_NO_ROTATE);

   nativewindow.element = dispman_element;
   nativewindow.width = state->screen_width;
   nativewindow.height = state->screen_height;
   vc_dispmanx_update_submit_sync( dispman_update );

   state->surface = eglCreateWindowSurface( state->display, config, &nativewindow, NULL );
   assert(state->surface != EGL_NO_SURFACE);

   result = eglMakeCurrent(state->display, state->surface, state->surface, state->context);
   assert(EGL_FALSE != result);
}

static void exit_func(void) {
   eglMakeCurrent( state->display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT );
   eglDestroySurface( state->display, state->surface );
   eglDestroyContext( state->display, state->context );
   eglTerminate( state->display );
   bcm_host_deinit();
}

int main(int argc, char *argv[]) {
    bcm_host_init();
    memset( state, 0, sizeof( *state ) );
    init_ogl(state);

    printf("EGL Information:\n");
    printf("\tVendor:\t\t%s\n", eglQueryString(state->display, EGL_VENDOR));
    printf("\tVersion:\t%s\n", eglQueryString(state->display, EGL_VERSION));
    printf("\tClient APIs:\t%s\n", eglQueryString(state->display, EGL_CLIENT_APIS));
    printf("\tExtensions:\t%s\n", eglQueryString(state->display, EGL_EXTENSIONS));
    printf("\n");
    printf("OpenGL Information:\n");
    printf("\tVendor:\t\t%s\n", glGetString(GL_VENDOR));
    printf("\tRenderer:\t%s\n", glGetString(GL_RENDERER));
    printf("\tVersion:\t%s\n", glGetString(GL_VERSION));
    printf("\tExtensions:\t%s\n", glGetString(GL_EXTENSIONS));
    printf("\n");

    glViewport(0, 0, (GLsizei) state->screen_width, (GLsizei) state->screen_height);
    glClearColor(1, 0, 0, 1);
    glClearStencil(0);
    glStencilMask(0xffffffff);
    glClear(GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    sk_sp<const GrGLInterface> interface(GrGLCreateNativeInterface());
    sk_sp<GrContext> grContext(GrContext::Create(kOpenGL_GrBackend, (GrBackendContext)interface.get()));
    GrBackendRenderTargetDesc desc;
    desc.fWidth = state->screen_width;
    desc.fHeight = state->screen_height;
    desc.fConfig = kSkia8888_GrPixelConfig;
    desc.fOrigin = kBottomLeft_GrSurfaceOrigin;
    desc.fSampleCnt = 0;
    desc.fStencilBits = 8;
    desc.fRenderTargetHandle = 0;
    SkSurface *surface = SkSurface::MakeFromBackendRenderTarget(grContext.release(), desc, nullptr, nullptr).release();
    SkCanvas *canvas = surface->getCanvas();

    canvas->clear(SK_ColorBLUE);

    // SkRect rect = SkRect::MakeXYWH(0, 0, 100, 100);
    // SkPaint paint;
    // paint.setColor(SK_ColorBLUE);
    // canvas->drawRect(rect, paint);

    canvas->flush();
    eglSwapBuffers(state->display, state->surface);

    getchar();
    exit_func();
    printf("Finished!\n");
    return 0;
}

with_draw.txt

EGL Information:
	Vendor:		     Broadcom
	Version:	     1.4
	Client APIs:	 OpenGL_ES OpenVG
	Extensions:	   EGL_KHR_image EGL_KHR_image_base EGL_KHR_image_pixmap EGL_KHR_vg_parent_image EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_lock_surface 

OpenGL Information:
	Vendor:		  Broadcom
	Renderer:	  VideoCore IV HW
	Version:	  OpenGL ES 2.0
	Extensions:	GL_OES_compressed_ETC1_RGB8_texture GL_OES_compressed_paletted_texture GL_OES_texture_npot GL_OES_depth24 GL_OES_vertex_half_float GL_OES_EGL_image GL_OES_EGL_image_external GL_EXT_discard_framebuffer GL_OES_rgb8_rgba8 GL_OES_depth32 GL_OES_mapbuffer GL_EXT_texture_format_BGRA8888 GL_APPLE_rgb_422 GL_EXT_debug_marker

ERROR:LEX/PARSE-2 (vertex shader, line 12) Undefined identifier../../src/gpu/gl/builders/GrGLProgramBuilder.cpp:207: fatal error: "Error linking program"
Aborted

without_draw.txt

EGL Information:
	Vendor:		     Broadcom
	Version:	     1.4
	Client APIs:	 OpenGL_ES OpenVG
	Extensions:	   EGL_KHR_image EGL_KHR_image_base EGL_KHR_image_pixmap EGL_KHR_vg_parent_image EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_lock_surface 

OpenGL Information:
	Vendor:		  Broadcom
	Renderer:	  VideoCore IV HW
	Version:	  OpenGL ES 2.0
	Extensions:	GL_OES_compressed_ETC1_RGB8_texture GL_OES_compressed_paletted_texture GL_OES_texture_npot GL_OES_depth24 GL_OES_vertex_half_float GL_OES_EGL_image GL_OES_EGL_image_external GL_EXT_discard_framebuffer GL_OES_rgb8_rgba8 GL_OES_depth32 GL_OES_mapbuffer GL_EXT_texture_format_BGRA8888 GL_APPLE_rgb_422 GL_EXT_debug_marker 


Finished!