From 9b455e24a2fb3fc77dc010954f0c2aa34e11afc2 Mon Sep 17 00:00:00 2001 From: Simon Ser Date: Mon, 10 Oct 2022 10:06:45 +0200 Subject: [PATCH] clients/simple-dmabuf-egl: drop Y_INVERT flag The motivations for this are: - Y_INVERT is not used by most real-world clients. weston-simple-dmabuf-egl and weston-simple-dmabuf-v4l are one only known users. Thus this creates a special case just for these demo clients. - Some compositors (wlroots) have dropped support for DMA-BUF flags, so the client no longer runs there. - Dropping the flag allows compositors to use a KMS hardware plane to display the buffer. It keeps the same axis orientation we had in place where we had the y-invert flag enabled by default, by doing a reflection about x-axis. Signed-off-by: Simon Ser Signed-off-by: Marius Vlad Closes: https://gitlab.freedesktop.org/wayland/weston/-/issues/675 --- clients/meson.build | 3 ++- clients/simple-dmabuf-egl.c | 50 +++++++++++++++++++++++++++---------- 2 files changed, 39 insertions(+), 14 deletions(-) diff --git a/clients/meson.build b/clients/meson.build index 8e6446a8..77b491ae 100644 --- a/clients/meson.build +++ b/clients/meson.build @@ -102,7 +102,8 @@ simple_clients = [ 'dep_objs': [ dep_wayland_client, dep_libdrm, - dep_libm + dep_libm, + dep_matrix_c, ], 'deps': [ 'egl', 'glesv2', 'gbm' ], 'options': [ 'renderer-gl' ] diff --git a/clients/simple-dmabuf-egl.c b/clients/simple-dmabuf-egl.c index e63c320c..aed9b43c 100644 --- a/clients/simple-dmabuf-egl.c +++ b/clients/simple-dmabuf-egl.c @@ -58,6 +58,7 @@ #include #include +#include #include "shared/weston-egl-ext.h" /* Possible options that affect the displayed image */ @@ -149,6 +150,7 @@ struct window { GLuint pos; GLuint color; GLuint offset_uniform; + GLuint reflection_uniform; } gl; bool render_mandelbrot; }; @@ -329,9 +331,7 @@ static int create_dmabuf_buffer(struct display *display, struct buffer *buffer, int width, int height, uint32_t opts) { - /* Y-Invert the buffer image, since we are going to renderer to the - * buffer through a FBO. */ - static uint32_t flags = ZWP_LINUX_BUFFER_PARAMS_V1_FLAGS_Y_INVERT; + static uint32_t flags = 0; struct zwp_linux_buffer_params_v1 *params; int i; @@ -411,15 +411,8 @@ create_dmabuf_buffer(struct display *display, struct buffer *buffer, params = zwp_linux_dmabuf_v1_create_params(display->dmabuf); - if ((opts & OPT_DIRECT_DISPLAY) && display->direct_display) { + if ((opts & OPT_DIRECT_DISPLAY) && display->direct_display) weston_direct_display_v1_enable(display->direct_display, params); - /* turn off Y_INVERT otherwise linux-dmabuf will reject it and - * we need all dmabuf flags turned off */ - flags &= ~ZWP_LINUX_BUFFER_PARAMS_V1_FLAGS_Y_INVERT; - - fprintf(stdout, "image is y-inverted as direct-display flag was set, " - "dmabuf y-inverted attribute flag was removed\n"); - } for (i = 0; i < buffer->plane_count; ++i) { zwp_linux_buffer_params_v1_add(params, @@ -503,11 +496,12 @@ static const struct xdg_toplevel_listener xdg_toplevel_listener = { static const char *vert_shader_text = "uniform float offset;\n" + "uniform mat4 reflection;\n" "attribute vec4 pos;\n" "attribute vec4 color;\n" "varying vec4 v_color;\n" "void main() {\n" - " gl_Position = pos + vec4(offset, offset, 0.0, 0.0);\n" + " gl_Position = reflection * (pos + vec4(offset, offset, 0.0, 0.0));\n" " v_color = color;\n" "}\n"; @@ -520,11 +514,12 @@ static const char *frag_shader_text = static const char *vert_shader_mandelbrot_text = "uniform float offset;\n" + "uniform mat4 reflection;\n" "attribute vec4 pos;\n" "varying vec2 v_pos;\n" "void main() {\n" " v_pos = pos.xy;\n" - " gl_Position = pos + vec4(offset, offset, 0.0, 0.0);\n" + " gl_Position = reflection * (pos + vec4(offset, offset, 0.0, 0.0));\n" "}\n"; @@ -624,6 +619,8 @@ window_set_up_gl(struct window *window) window->gl.offset_uniform = glGetUniformLocation(window->gl.program, "offset"); + window->gl.reflection_uniform = + glGetUniformLocation(window->gl.program, "reflection"); return window->gl.program != 0; } @@ -803,6 +800,7 @@ render(struct window *window, struct buffer *buffer) GLfloat offset; struct timeval tv; uint64_t time_ms; + struct weston_matrix reflection; gettimeofday(&tv, NULL); time_ms = tv.tv_sec * 1000 + tv.tv_usec / 1000; @@ -811,12 +809,32 @@ render(struct window *window, struct buffer *buffer) * to offsets in the [-0.5, 0.5) range. */ offset = (time_ms % iteration_ms) / (float) iteration_ms - 0.5; + weston_matrix_init(&reflection); + /* perform a reflection about x-axis to keep the same orientation of + * the vertices colors, as outlined in the comment at the beginning + * of this function. + * + * We need to render upside-down, because rendering through an FBO + * causes the bottom of the image to be written to the top pixel row of + * the buffer, y-flipping the image. + * + * Reflection is a specialized version of scaling with the + * following matrix: + * + * [1, 0, 0] + * [0, -1, 0] + * [0, 0, 1] + */ + weston_matrix_scale(&reflection, 1, -1, 1); + /* Direct all GL draws to the buffer through the FBO */ glBindFramebuffer(GL_FRAMEBUFFER, buffer->gl_fbo); glViewport(0, 0, window->width, window->height); glUniform1f(window->gl.offset_uniform, offset); + glUniformMatrix4fv(window->gl.reflection_uniform, 1, GL_FALSE, + (GLfloat *) reflection.d); glClearColor(0.0,0.0, 0.0, 1.0); glClear(GL_COLOR_BUFFER_BIT); @@ -846,6 +864,7 @@ render_mandelbrot(struct window *window, struct buffer *buffer) struct timeval tv; uint64_t time_ms; int i; + struct weston_matrix reflection; gettimeofday(&tv, NULL); time_ms = tv.tv_sec * 1000 + tv.tv_usec / 1000; @@ -854,12 +873,17 @@ render_mandelbrot(struct window *window, struct buffer *buffer) * to offsets in the [-0.5, 0.5) range. */ offset = (time_ms % iteration_ms) / (float) iteration_ms - 0.5; + weston_matrix_init(&reflection); + weston_matrix_scale(&reflection, 1, -1, 1); + /* Direct all GL draws to the buffer through the FBO */ glBindFramebuffer(GL_FRAMEBUFFER, buffer->gl_fbo); glViewport(0, 0, window->width, window->height); glUniform1f(window->gl.offset_uniform, offset); + glUniformMatrix4fv(window->gl.reflection_uniform, 1, GL_FALSE, + (GLfloat *) reflection.d); glClearColor(0.6, 0.6, 0.6, 1.0); glClear(GL_COLOR_BUFFER_BIT);