Steward
分享是一種喜悅、更是一種幸福
掌機 - Miyoo Flip - C/C++ - DRM/KMS - OpenGL ES 2.0 - Draw 2 Triangles
參考資訊:
https://gist.github.com/dvdhrm/5083553
https://www.kernel.org/doc/html/v4.15/gpu/drm-kms.html
https://github.com/grate-driver/libdrm/blob/master/xf86drmMode.h
https://gist.github.com/Miouyouyou/89e9fe56a2c59bce7d4a18a858f389ef
main.c
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 | #include <stdio.h> #include <stdlib.h> #include <string.h> #include <fcntl.h> #include <time.h> #include <sys/mman.h> #include <unistd.h> #include <gbm.h> #include <xf86drm.h> #include <xf86drmMode.h> #include <GLES2/gl2.h> #include <GLES2/gl2ext.h> #include <EGL/egl.h> #include <EGL/eglext.h> static int fd = -1; static int fb = -1; static int waiting_for_flip = 0; static drmModeRes *res = NULL ; static drmModeCrtc *crtc = NULL ; static drmModeEncoder *enc = NULL ; static drmModeConnector *conn = NULL ; static void flip_handler ( int fd, unsigned int frame, unsigned int sec, unsigned int usec, void * data ) { *(( int *) data ) = 0; } const char *vShaderSrc = "attribute vec4 vPosition; \n" "void main(void) \n" "{ \n" " const float angle = 90.0 * (3.1415 * 2.0) / 360.0; \n" " mat4 rot = mat4(cos(angle), -sin(angle), 0.0, 0.0, sin(angle), cos(angle), 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0); \n" " gl_Position = vPosition * rot; \n" "}" ; const char *fShaderSrc = "#ifdef GL_ES \n" "precision mediump float; \n" "#endif \n" "uniform vec4 vColor; \n" "void main(void) \n" "{ \n" " gl_FragColor = vColor; \n" "}" ; drmEventContext evctx = { .version = DRM_EVENT_CONTEXT_VERSION , .page_flip_handler = flip_handler , }; int main ( int argc, char *argv[]) { const int w = 640; const int h = 480; const int bpp = 32; const int depth = 24; int i = 0; int j = 0; fd = open ( "/dev/dri/card0" , O_RDWR | O_CLOEXEC ); res = drmModeGetResources (fd); conn = drmModeGetConnector (fd, res->connectors[1]); enc = drmModeGetEncoder (fd, res->encoders[2]); crtc = drmModeGetCrtc (fd, res->crtcs[1]); struct gbm_device *gbm = gbm_create_device (fd); struct gbm_surface *gs = gbm_surface_create (gbm, crtc-> mode .hdisplay, crtc-> mode .vdisplay, GBM_FORMAT_XRGB8888 , GBM_BO_USE_SCANOUT | GBM_BO_USE_RENDERING ); EGLint egl_major = 0; EGLint egl_minor = 0; EGLint num_configs = 0; EGLConfig configs = {0}; EGLDisplay display = EGL_NO_DISPLAY ; EGLSurface surface = EGL_NO_SURFACE ; EGLContext context = EGL_NO_CONTEXT ; EGLint config_attribs[] = { EGL_SURFACE_TYPE , EGL_WINDOW_BIT , EGL_RENDERABLE_TYPE , EGL_OPENGL_ES2_BIT , EGL_RED_SIZE , 1, EGL_GREEN_SIZE , 1, EGL_BLUE_SIZE , 1, EGL_ALPHA_SIZE , 0, EGL_NONE }; EGLint const context_attributes[] = { EGL_CONTEXT_CLIENT_VERSION , 2, EGL_NONE , }; GLuint vShader = 0; GLuint fShader = 0; GLuint pObject = 0; GLint compiled = 0; GLfloat vVertices[] = { 0.0f, 0.5f, 0.0f, -0.5f, -0.5f, 0.0f, 0.5f, -0.5f, 0.0f }; PFNEGLGETPLATFORMDISPLAYEXTPROC get_platform_display = NULL ; get_platform_display = ( void *) eglGetProcAddress ( "eglGetPlatformDisplayEXT" ); display = get_platform_display ( EGL_PLATFORM_GBM_KHR , gbm, NULL ); eglInitialize ( display , &egl_major, &egl_minor); eglBindAPI ( EGL_OPENGL_ES_API ); eglChooseConfig ( display , config_attribs, &configs, 1, &num_configs); surface = eglCreateWindowSurface ( display , configs, gs, NULL ); context = eglCreateContext ( display , configs, EGL_NO_CONTEXT , context_attributes); eglMakeCurrent ( display , surface, surface, context ); vShader = glCreateShader ( GL_VERTEX_SHADER ); glShaderSource (vShader, 1, &vShaderSrc, NULL ); glCompileShader (vShader); glGetShaderiv (vShader, GL_COMPILE_STATUS , &compiled); fShader = glCreateShader ( GL_FRAGMENT_SHADER ); glShaderSource (fShader, 1, &fShaderSrc, NULL ); glCompileShader (fShader); glGetShaderiv (fShader, GL_COMPILE_STATUS , &compiled); pObject = glCreateProgram (); glAttachShader (pObject, vShader); glAttachShader (pObject, fShader); glLinkProgram (pObject); glUseProgram (pObject); glViewport (0, 0, w, h); glClearColor (0.0f, 0.0f, 0.0f, 1.0f); glClear ( GL_COLOR_BUFFER_BIT ); GLuint vp = glGetAttribLocation (pObject, "vPosition" ); GLuint vc = glGetUniformLocation (pObject, "vColor" ); glViewport (0, 0, w, h); glClear ( GL_COLOR_BUFFER_BIT ); vVertices[0] = 0.0; vVertices[1] = 1.0; vVertices[2] = 0.0; vVertices[3] = -1.0; vVertices[4] = 0.0; vVertices[5] = 0.0; vVertices[6] = 0.0; vVertices[7] = 0.0; vVertices[8] = 0.0; glVertexAttribPointer (vp, 3, GL_FLOAT , GL_FALSE , 0, vVertices); glEnableVertexAttribArray (vp); glUniform4f (vc, 1.0f, 0.0f, 0.0f, 1.0f); glDrawArrays ( GL_TRIANGLES , 0, 3); vVertices[0] = 0.0; vVertices[1] = 0.0; vVertices[2] = 0.0; vVertices[3] = 0.0; vVertices[4] = -1.0; vVertices[5] = 0.0; vVertices[6] = 1.0; vVertices[7] = -1.0; vVertices[8] = 0.0; glVertexAttribPointer (vp, 3, GL_FLOAT , GL_FALSE , 0, vVertices); glUniform4f (vc, 0.0f, 1.0f, 0.0f, 1.0f); glDrawArrays ( GL_TRIANGLES , 0, 3); eglSwapBuffers ( display , surface); struct gbm_bo *bo = gbm_surface_lock_front_buffer (gs); drmModeAddFB (fd, w, h, depth, bpp, gbm_bo_get_stride (bo), gbm_bo_get_handle (bo). u32 , &fb); drmModeSetCrtc (fd, crtc->crtc_id, fb, 0, 0, ( uint32_t *)conn, 1, &crtc-> mode ); waiting_for_flip = 1; drmModePageFlip (fd, crtc->crtc_id, fb, DRM_MODE_PAGE_FLIP_EVENT , ( void *)&waiting_for_flip); while (waiting_for_flip) { drmHandleEvent (fd, &evctx); } gbm_surface_release_buffer (gs, bo); sleep (3); eglMakeCurrent ( display , EGL_NO_SURFACE , EGL_NO_SURFACE , EGL_NO_CONTEXT ); eglDestroyContext ( display , context ); eglDestroySurface ( display , surface); drmModeRmFB (fd, fb); drmModeFreeCrtc (crtc); drmModeFreeEncoder (enc); drmModeFreeConnector (conn); drmModeFreeResources (res); close (fd); return 0; } |
編譯、執行
$ /opt/flip/bin/aarch64-linux-gcc main.c -O3 -o main -I/opt/flip/aarch64-flip-linux-gnu/sysroot/usr/include/libdrm -ldrm -lEGL -lGLESv2 -lgbm root@rk3566-buildroot:/mnt/SDCARD# ./main