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Implement basic cairo rendering loop

This commit is contained in:
Hans-Joerg Schurr 2020-04-27 19:54:27 +02:00
parent 6b14f544e7
commit 76afd0b903
2 changed files with 142 additions and 81 deletions

View File

@ -15,16 +15,10 @@
#endif
/* TODO:
* 1. Draw the path in each shape as outline
* 2. Then do the same for the styles
* 3. Put everything together
*/
/* TODO: Gradients
* - Check the various forms
* - How is the gradient oriented in the picture
* - Apply transformation matrix
* - Color space
* - Contour
* - LOD
* - Check miter limit
*/
void
@ -37,22 +31,10 @@ cairo_matrix_init_from_matrix(
}
void
create_path(cairo_t* cr, hvif_path* path)
print_matrix(const hvif_matrix* matrix)
{
assert(path->num_points > 0);
for (unsigned i = 0; i < path->num_points; ++i) {
hvif_point p = path->points[3 * i];
hvif_point cp1 = path->points[3 * i + 1];
hvif_point cp2 = path->points[3 * i + 2];
uint8_t command = path_command_at(path, i);
if (command == PATH_COMMAND_CURVE)
cairo_curve_to(cr, cp1.x, cp1.y, cp2.x, cp2.y, p.x, p.y);
else
cairo_line_to(cr, p.x, p.y);
}
if (path->closed) cairo_close_path(cr);
printf("x_new = %f * x + %f * y + %f\n", matrix->xx, matrix->xy, matrix->x0);
printf("y_new = %f * x + %f * y + %f\n", matrix->yx, matrix->yy, matrix->y0);
}
#define R(c) (COLOR_GET_RED(c) / 255.0)
@ -124,7 +106,6 @@ create_conic_patch(
cos2, sin2);
cairo_mesh_pattern_line_to(pat, 0, 0);
cairo_mesh_pattern_set_corner_color_rgba(pat, 0, R(c1), G(c1), B(c1), A(c1));
//cairo_mesh_pattern_set_corner_color_rgb(pat, 0, 0, 0, 0);
cairo_mesh_pattern_set_corner_color_rgba(pat, 1, R(c1), G(c1), B(c1), A(c1));
cairo_mesh_pattern_set_corner_color_rgba(pat, 2, R(c2), G(c2), B(c2), A(c2));
cairo_mesh_pattern_set_corner_color_rgba(pat, 3, R(c2), G(c2), B(c2), A(c2));
@ -132,10 +113,9 @@ create_conic_patch(
}
void
create_style(cairo_t* cr, hvif_style* style)
create_pattern_style(cairo_pattern_t** pat, hvif_style* style)
{
assert(style->num_stops > 0);
cairo_pattern_t* pat;
double width = 64.0;
double height = 64.0;
@ -146,69 +126,66 @@ create_style(cairo_t* cr, hvif_style* style)
switch (style->gradient_type) {
case GRADIENT_LINEAR:
printf("GRADIENT_LINEAR\n");
pat = cairo_pattern_create_linear(-64, 32, 64, 32);
*pat = cairo_pattern_create_linear(-64, 32, 64, 32);
for (unsigned i = 0; i < style->num_stops; ++i) {
hvif_color c = style->colors[i];
cairo_pattern_add_color_stop_rgba(
pat, style->offsets[i], R(c), G(c), B(c), A(c));
*pat, style->offsets[i], R(c), G(c), B(c), A(c));
}
break;
case GRADIENT_CIRCULAR:
printf("GRADIENT_CIRCULAR\n");
pat = cairo_pattern_create_radial(0, 0, 0, 0, 0, 64);
*pat = cairo_pattern_create_radial(0, 0, 0, 0, 0, 64);
for (unsigned i = 0; i < style->num_stops; ++i) {
hvif_color c = style->colors[i];
cairo_pattern_add_color_stop_rgba(
pat, style->offsets[i], R(c), G(c), B(c), A(c));
*pat, style->offsets[i], R(c), G(c), B(c), A(c));
}
break;
case GRADIENT_DIAMOND:
printf("GRADIENT_DIAMOND\n");
pat = cairo_pattern_create_mesh();
*pat = cairo_pattern_create_mesh();
if (style->offsets[0] != 0.0) {
create_diamond_patch(
pat, 0, 64.0 * style->offsets[0], style->colors[0], style->colors[0]);
*pat, 0, 64.0 * style->offsets[0], style->colors[0],
style->colors[0]);
}
for (unsigned i = 0; i + 1 < style->num_stops; ++i) {
double s1 = style->offsets[i] * 64.0;
double s2 = style->offsets[i + 1] * 64.0;
hvif_color c1 = style->colors[i];
hvif_color c2 = style->colors[i + 1];
create_diamond_patch(pat, s1, s2, c1, c2);
create_diamond_patch(*pat, s1, s2, c1, c2);
}
unsigned i = style->num_stops - 1;
create_diamond_patch(
pat, 64.0 * style->offsets[i], extremum, style->colors[i],
*pat, 64.0 * style->offsets[i], extremum, style->colors[i],
style->colors[i]);
break;
case GRADIENT_CONIC:
printf("GRADIENT_CONIC\n");
pat = cairo_pattern_create_mesh();
*pat = cairo_pattern_create_mesh();
if (style->offsets[0] != 0.0) {
create_conic_patch(
pat, extremum, 0, M_PI * style->offsets[0], style->colors[0],
*pat, extremum, 0, M_PI * style->offsets[0], style->colors[0],
style->colors[0]);
create_conic_patch(
pat, extremum, 0, -M_PI * style->offsets[0], style->colors[0],
*pat, extremum, 0, -M_PI * style->offsets[0], style->colors[0],
style->colors[0]);
}
for (unsigned i = 0; i + 1 < style->num_stops; ++i) {
create_conic_patch(
pat, extremum, M_PI * style->offsets[i], M_PI * style->offsets[i + 1],
style->colors[i], style->colors[i + 1]);
*pat, extremum, M_PI * style->offsets[i],
M_PI * style->offsets[i + 1], style->colors[i], style->colors[i + 1]);
create_conic_patch(
pat, extremum, -M_PI * style->offsets[i],
*pat, extremum, -M_PI * style->offsets[i],
-M_PI * style->offsets[i + 1], style->colors[i],
style->colors[i + 1]);
}
i = style->num_stops - 1;
if (style->offsets[i] != 1.0) {
create_conic_patch(
pat, extremum, M_PI * style->offsets[i], 0, style->colors[i],
*pat, extremum, M_PI * style->offsets[i], 0, style->colors[i],
style->colors[i]);
create_conic_patch(
pat, extremum, -M_PI * style->offsets[i], 0, style->colors[i],
*pat, extremum, -M_PI * style->offsets[i], 0, style->colors[i],
style->colors[i]);
}
break;
@ -220,55 +197,138 @@ create_style(cairo_t* cr, hvif_style* style)
if (cairo_matrix_invert(&transformation) != CAIRO_STATUS_SUCCESS) {
printf("could not invert style transformation\n");
exit(1);
}
cairo_pattern_set_matrix(pat, &transformation);
} else
cairo_pattern_set_matrix(*pat, &transformation);
}
cairo_rectangle(cr, 0, 0, 64, 64);
cairo_set_source(cr, pat);
cairo_fill(cr);
cairo_pattern_destroy(pat);
void
create_path(cairo_t* cr, cairo_path_t** path, hvif_path* hvif_path)
{
assert(hvif_path->num_points > 0);
cairo_new_path(cr);
cairo_move_to(cr, hvif_path->points[0].x, hvif_path->points[0].y);
for (unsigned i = 1; i < hvif_path->num_points; ++i) {
hvif_point cp1 = hvif_path->points[3 * i - 1];
hvif_point cp2 = hvif_path->points[3 * i + 1];
hvif_point p = hvif_path->points[3 * i];
cairo_curve_to(cr, cp1.x, cp1.y, cp2.x, cp2.y, p.x, p.y);
}
if (hvif_path->closed) {
unsigned max = hvif_path->num_points - 1;
hvif_point cp1 = hvif_path->points[3 * max + 2];
hvif_point cp2 = hvif_path->points[1];
hvif_point p = hvif_path->points[0];
cairo_curve_to(cr, cp1.x, cp1.y, cp2.x, cp2.y, p.x, p.y);
}
cairo_close_path(cr);
*path = cairo_copy_path_flat(cr);
}
void
render_shape(
cairo_t* cr, hvif_shape* shape, cairo_pattern_t** pattern,
cairo_path_t** path)
{
cairo_matrix_t old_transform;
cairo_get_matrix(cr, &old_transform);
cairo_matrix_t shape_transform;
cairo_matrix_init_from_matrix(&shape_transform, &shape->transformation);
cairo_transform(cr, &shape_transform);
int stroke_idx = -1;
for (unsigned i = 0; i < shape->num_transformers; ++i) {
hvif_transformer* t = &shape->transformers[i];
switch (t->transformer_type) {
case TRANSFORMER_TYPE_STROKE:
if (stroke_idx != -1)
printf("unsupported: multiple stroke transform\n");
stroke_idx = i;
break;
case TRANSFORMER_TYPE_AFFINE:
/* TODO: this is a guess what this does, but it's not exposed in
Icon-o-Matic. */
printf("warning: affine transform\n");
cairo_matrix_init_from_matrix(
&shape_transform, &t->transformer.affine.matrix);
break;
default: printf("unsupported: transform\n");
}
}
cairo_new_path(cr);
for (unsigned i = 0; i < shape->num_paths; ++i) {
cairo_append_path(cr, path[shape->path_idxs[i]]);
cairo_new_sub_path(cr);
}
cairo_set_source(cr, pattern[shape->style_idx]);
if (stroke_idx >= 0) {
hvif_transformer* t = &shape->transformers[stroke_idx];
cairo_set_line_width(cr, t->transformer.stroke.width);
switch (t->transformer.stroke.line_join) {
case (MITER_JOIN): cairo_set_line_join(cr, CAIRO_LINE_JOIN_MITER); break;
case (ROUND_CAP): cairo_set_line_join(cr, CAIRO_LINE_JOIN_ROUND); break;
case (BEVEL_JOIN): cairo_set_line_join(cr, CAIRO_LINE_JOIN_BEVEL); break;
default: printf("unsupported: line join\n");
}
cairo_set_miter_limit(cr, t->transformer.stroke.miter_limit);
switch (t->transformer.stroke.line_cap) {
case (BUTT_CAP): cairo_set_line_cap(cr, CAIRO_LINE_CAP_BUTT); break;
case (SQUARE_CAP): cairo_set_line_cap(cr, CAIRO_LINE_CAP_SQUARE); break;
case (ROUND_CAP): cairo_set_line_cap(cr, CAIRO_LINE_CAP_ROUND); break;
default: printf("illegal line cap"); exit(1);
}
cairo_stroke(cr);
} else
cairo_fill(cr);
cairo_set_matrix(cr, &old_transform);
if (shape->hinting) printf("unsupported: hinting\n");
/* TODO: implement LOD */
}
bool
hvif_render_image(const char* filename, hvif_image* image)
{
unsigned image_size = 512;
cairo_surface_t* surface =
/* cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 254, 254); */
cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 64, 64);
cairo_image_surface_create(CAIRO_FORMAT_ARGB32, image_size, image_size);
cairo_t* cr = cairo_create(surface);
/* cairo_scale(cr, 4.0, 4.0); */
cairo_scale(cr, 1.0, 1.0);
cairo_scale(cr, image_size / 64.0, image_size / 64.0);
cairo_set_line_width(cr, 0.2);
cairo_pattern_t** patterns =
malloc(sizeof(cairo_pattern_t*) * image->num_styles);
if (!patterns) return false;
cairo_path_t** paths = malloc(sizeof(cairo_path_t*) * image->num_paths);
if (!paths) return false;
double r = 0;
double delta = 1.0 / image->num_shapes;
printf("styles %u\n", image->num_styles);
create_style(cr, &image->styles[0]);
/*
for (unsigned i = 0; i < image->num_shapes; ++i) {
cairo_set_source_rgb(cr, r, 0, 0);
r = r + delta;
hvif_shape s = image->shapes[i];
if (s.hinting)
printf("shape %u has hinting\n", i);
else
printf("shape %u has no hinting\n", i);
for (unsigned j = 0; j < s.num_paths; ++j) {
hvif_path* p = &image->paths[s.path_idxs[j]];
create_path(cr, p);
cairo_stroke(cr);
}
for (unsigned i = 0; i < image->num_styles; ++i) {
create_pattern_style(&patterns[i], &image->styles[i]);
/* TODO: error handling */
}
for (unsigned i = 0; i < image->num_paths; ++i) {
create_path(cr, &paths[i], &image->paths[i]);
/* TODO: error handling */
}
*/
cairo_destroy(cr);
for (unsigned i = 0; i < image->num_shapes; ++i) {
render_shape(cr, &image->shapes[i], patterns, paths);
}
for (unsigned i = 0; i < image->num_paths; ++i) {
cairo_path_destroy(paths[i]);
}
for (unsigned i = 0; i < image->num_styles; ++i) {
cairo_pattern_destroy(patterns[i]);
}
bool result = true;
if (cairo_surface_write_to_png(surface, filename) != CAIRO_STATUS_SUCCESS)
result = false;
cairo_surface_destroy(surface);
cairo_destroy(cr);
return result;
}

View File

@ -156,7 +156,7 @@ struct hvif_transformer
/* perspective is empty */
struct
{
uint8_t width;
double width;
hvif_line_join line_join;
hvif_line_cap line_cap;
double miter_limit;
@ -304,6 +304,7 @@ read_color_style(hvif_style* style, uint8_t* buffer, bool gray, bool alpha)
style->colors[0] = color;
style->offsets[0] = 1.0; /* TODO: Is this ok for solid colors */
style->transformation = MATRIX_ID;
return SUCCESS;
}