WIP: Initial cairo support

Implements: * image_ops_create (TODO: image_ops_update/image_ops_delete) * font_ops_create (Using cairo w/ freetype2) * script_ops_draw_line * script_ops_draw_rect * script_ops_draw_rrect * script_ops_draw_circle * script_ops_draw_text * script_ops_begin_path * script_ops_close_path * script_ops_fill_path * script_ops_stroke_path * script_ops_move_to * script_ops_line_to * script_ops_push_state * script_ops_pop_state * script_ops_translate * script_ops_fill_color * script_ops_fill_linear * script_ops_fill_image * script_ops_stroke_width * script_ops_stroke_color * script_ops_line_cap * script_ops_line_join * script_ops_miter_limit * script_ops_font * script_ops_font_size * script_ops_text_align * script_ops_text_base Signed-off-by: Jon Ringle <[email protected]>
ScenicFramework · Jul 21, 2023 · 6387f93 · 6387f93
1 parent 1e08742
commit 6387f93
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diff --git a/Makefile b/Makefile
@@ -125,6 +125,18 @@ else ifeq ($(SCENIC_LOCAL_TARGET),drm)
 	else 
 		CFLAGS += -DSCENIC_GLES3
 	endif
+else ifeq ($(SCENIC_LOCAL_TARGET),cairo)
+	LDFLAGS += `pkg-config --static --libs freetype2 cairo`
+	CFLAGS += `pkg-config --static --cflags freetype2 cairo`
+	LDFLAGS += -lm
+	CFLAGS ?= -O2 -Wall -Wextra -Wno-unused-parameter -pedantic
+	CFLAGS += -std=gnu99
+
+	DEVICE_SRCS += \
+		c_src/device/cairo.c
+	FONT_SRCS += c_src/font/cairo_font_ops.c
+	IMAGE_SRCS += c_src/image/cairo_image_ops.c
+	SCENIC_SRCS += c_src/scenic/ops/cairo_script_ops.c
 else
 $(info ------ no SCENIC_LOCAL_TARGET set ------)
 $(info If you get here, then you are probably using a custom Nerves system)

diff --git a/c_src/device/cairo.c b/c_src/device/cairo.c
@@ -0,0 +1,152 @@
+#include <cairo.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fb.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "cairo_ctx.h"
+#include "comms.h"
+#include "device.h"
+#include "fontstash.h"
+#include "ops/script_ops.h"
+
+const char* device = "/dev/fb0";
+
+typedef struct {
+  int fd;
+
+  struct fb_var_screeninfo var;
+  struct fb_fix_screeninfo fix;
+} cairo_fb_t;
+
+cairo_fb_t g_cairo_fb = {0};
+
+extern device_info_t g_device_info;
+extern device_opts_t g_opts;
+
+int device_init(const device_opts_t* p_opts,
+                device_info_t* p_info,
+                driver_data_t* p_data)
+{
+  if (g_opts.debug_mode) {
+    log_info("cairo %s", __func__);
+  }
+
+  if ((g_cairo_fb.fd = open(device, O_RDWR)) == -1) {
+    log_error("Failed to open device %s: %s", device, strerror(errno));
+    return -1;
+  }
+
+  if (ioctl(g_cairo_fb.fd, FBIOGET_VSCREENINFO, &g_cairo_fb.var)) {
+    log_error("Failed to get fb_var_screeninfo: %s", strerror(errno));
+    return -1;
+  }
+
+  if (ioctl(g_cairo_fb.fd, FBIOGET_FSCREENINFO, &g_cairo_fb.fix)) {
+    log_error("Failed to get fb_fix_screeninfo: %s", strerror(errno));
+    return -1;
+  }
+
+  CAIROcontext_t* p_ctx = (CAIROcontext_t*)calloc(1, sizeof(CAIROcontext_t));
+
+  FT_Error status = FT_Init_FreeType(&p_ctx->ft_library);
+  if (status != 0) {
+    log_error("cairo: FT_Init_FreeType: Error: %d", status);
+    close(g_cairo_fb.fd);
+    free(p_ctx);
+
+    return -1;
+  }
+
+  p_info->width = g_cairo_fb.var.xres;
+  p_info->height = g_cairo_fb.var.yres;
+
+  p_ctx->font_size = 10.0; // Cairo default
+  p_ctx->text_align = TEXT_ALIGN_LEFT;
+  p_ctx->text_base = TEXT_BASE_ALPHABETIC;
+
+  p_info->v_ctx = p_ctx;
+
+  p_ctx->surface = cairo_image_surface_create(CAIRO_FORMAT_RGB24,
+                                              p_info->width, p_info->height);
+  return 0;
+}
+
+int device_close(device_info_t* p_info)
+{
+  if (g_opts.debug_mode) {
+    log_info("cairo %s", __func__);
+  }
+  close(g_cairo_fb.fd);
+
+  CAIROcontext_t* p_ctx = (CAIROcontext_t*)p_info->v_ctx;
+  cairo_surface_destroy(p_ctx->surface);
+  free(p_ctx);
+}
+
+void device_poll()
+{
+}
+
+void device_begin_render(driver_data_t* p_data)
+{
+  if (g_opts.debug_mode) {
+    log_info("cairo %s", __func__);
+  }
+
+  CAIROcontext_t* p_ctx = (CAIROcontext_t*)p_data->v_ctx;
+
+  p_ctx->cr = cairo_create(p_ctx->surface);
+  cairo_set_source_rgb(p_ctx->cr, 0, 0, 0);
+}
+
+void device_begin_cursor_render(driver_data_t* p_data)
+{
+  CAIROcontext_t* p_ctx = (CAIROcontext_t*)p_data->v_ctx;
+  cairo_translate(p_ctx->cr, p_data->cursor_pos[0], p_data->cursor_pos[1]);
+}
+
+void cairo_render_surface_to_fb(int fd, cairo_surface_t* surface)
+{
+  cairo_surface_flush(surface);
+  uint8_t* surface_data = cairo_image_surface_get_data(surface);
+
+  int fb_x = g_cairo_fb.var.xres;
+  int fb_y = g_cairo_fb.var.yres;
+  size_t fb_size = fb_x * fb_y * 3;
+  uint8_t* fbbuff = mmap(NULL, fb_size, PROT_WRITE | PROT_READ, MAP_SHARED, fd, 0);
+
+  for(uint32_t i = 0, j = 0; i < fb_size; i += 3, j += 4) {
+    fbbuff[i+0] = surface_data[j+0];
+    fbbuff[i+1] = surface_data[j+1];
+    fbbuff[i+2] = surface_data[j+2];
+  }
+
+  munmap(fbbuff, fb_size);
+}
+
+void device_end_render(driver_data_t* p_data)
+{
+  if (g_opts.debug_mode) {
+    log_info("cairo %s", __func__);
+  }
+
+  CAIROcontext_t* p_ctx = (CAIROcontext_t*)p_data->v_ctx;
+  cairo_render_surface_to_fb(g_cairo_fb.fd, p_ctx->surface);
+
+  cairo_destroy(p_ctx->cr);
+}
+
+void device_clear_color(float red, float green, float blue, float alpha)
+{
+  log_warn("%s NOT IMPLEMENTED: {%.1f, %.1f, %.1f, %.1f", __func__, red, green, blue, alpha);
+}
+
+char* device_gl_error()
+{
+  return NULL;
+}
diff --git a/c_src/device/cairo_ctx.h b/c_src/device/cairo_ctx.h
@@ -0,0 +1,17 @@
+#pragma once
+
+#include <cairo.h>
+#include <ft2build.h>
+#include FT_FREETYPE_H
+#include "ops/script_ops.h"
+
+typedef struct {
+  FT_Library ft_library;
+  float font_size;
+  float scale_x;
+  float scale_y;
+  text_align_t text_align;
+  text_base_t text_base;
+  cairo_surface_t* surface;
+  cairo_t* cr;
+} CAIROcontext_t;
diff --git a/c_src/font/cairo_font_ops.c b/c_src/font/cairo_font_ops.c
@@ -0,0 +1,31 @@
+#include "cairo_ctx.h"
+#include "font_ops.h"
+
+#include <cairo-ft.h>
+int32_t font_ops_create(void* v_ctx, font_t* p_font, uint32_t size)
+{
+  CAIROcontext_t* p_ctx = (CAIROcontext_t*)v_ctx;
+  const char* name = p_font->id.p_data;
+  unsigned char* data = p_font->blob.p_data;
+
+  FT_Face ft_face;
+  FT_Error ft_status = FT_New_Memory_Face(p_ctx->ft_library, data, size, 0, &ft_face);
+
+  if (ft_status != 0) {
+    log_error("cairo: FT_New_Memory_Face: Error: %d", ft_status);
+    return -1;
+  }
+
+  cairo_font_face_t* font_face = cairo_ft_font_face_create_for_ft_face(ft_face, 0);
+  cairo_status_t status = cairo_font_face_set_user_data(font_face, NULL,
+                                                        ft_face,
+                                                        (cairo_destroy_func_t) FT_Done_Face);
+  if (status) {
+    log_error("cairo: Failed to create font face: %d", status);
+    cairo_font_face_destroy(font_face);
+    FT_Done_Face(ft_face);
+    return -1;
+  }
+
+  return (int32_t)font_face;
+}
diff --git a/c_src/image/cairo_image_ops.c b/c_src/image/cairo_image_ops.c
@@ -0,0 +1,56 @@
+#include <arpa/inet.h>
+#include <cairo.h>
+#include <stdlib.h>
+
+#include "comms.h"
+#include "image_ops.h"
+
+uint32_t convert_rgba_to_argb(uint32_t pixel)
+{
+  return ((pixel & 0xFFFFFF00) >> 8) | ((pixel & 0xFF) << 24);
+}
+
+int32_t image_ops_create(void* v_ctx,
+                         uint32_t width, uint32_t height,
+                         void* p_pixels)
+{
+  cairo_format_t format = CAIRO_FORMAT_ARGB32;
+  int stride = cairo_format_stride_for_width(format, width);
+  size_t num_pixels = width * height;
+  uint32_t* rgba_pixels = (uint32_t*)p_pixels;
+  uint32_t* argb_pixels = malloc(num_pixels * sizeof(uint32_t));
+
+  for(size_t i = 0; i < num_pixels; ++i) {
+    argb_pixels[i] = convert_rgba_to_argb(htonl(rgba_pixels[i]));
+  }
+
+  cairo_surface_t* surface
+    = cairo_image_surface_create_for_data((uint8_t*)argb_pixels,
+                                          format,
+                                          width, height, stride);
+
+  static cairo_user_data_key_t dummy_key;
+  cairo_surface_set_user_data(surface, &dummy_key, argb_pixels, free);
+
+  return (int32_t)surface;
+}
+
+void image_ops_update(void* v_ctx, uint32_t image_id, void* p_pixels)
+{
+  cairo_surface_t* surface = (cairo_surface_t*)image_id;
+  uint32_t width = cairo_image_surface_get_width(surface);
+  uint32_t height = cairo_image_surface_get_height(surface);
+  size_t num_pixels = width * height;
+  uint32_t* rgba_pixels = (uint32_t*)p_pixels;
+  uint32_t* argb_pixels = (uint32_t*)cairo_image_surface_get_data(surface);
+
+  for(size_t i = 0; i < num_pixels; ++i) {
+    argb_pixels[i] = convert_rgba_to_argb(htonl(rgba_pixels[i]));
+  }
+}
+
+void image_ops_delete(void* v_ctx, uint32_t image_id)
+{
+  cairo_surface_t* surface = (cairo_surface_t*)image_id;
+  cairo_surface_destroy(surface);
+}