peptide-repo/prautoblogger
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Separate comic captions from generated images

Browse Source 
Captions were being baked into the image by the FLUX model, causing
text to get cut off at the edges. Now the LLM generates scene and
caption separately — the scene drives image gen (with explicit
"no text in the image" instruction), and the caption is inserted
as a styled <figure>/<figcaption> HTML block at the top of the post.

Changes:
- rewrite_via_llm() returns array{scene, caption} instead of string
- build_article_prompt() and build_source_prompt() return {prompt, caption}
- Style suffix v4: removes "caption text" instruction, adds "no text" directive
- Image pipeline destructures prompt/caption, stores caption in attachment meta
- prepend_caption_to_post() inserts figure+figcaption HTML into post content
- Deduplicated generate_image_a/b into shared generate_single_image()
- One-time v4 migration auto-updates existing style suffix on deploy

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
peptiderepo
2026-04-18 15:15:59 +07:00
parent 389cb4d380
commit 214f57bff2
5 changed files with 174 additions and 144 deletions
Download Patch File Download Diff File Expand all files Collapse all files

87
includes/core/class-image-prompt-builder.php
View File

@@ -67,7 +67,9 @@ PROMPT;
* Build a visual prompt from finished article content.
*
* Tries LLM rewriting first; falls back to rule-based synthesis on failure.
* Appends the style suffix from plugin options.
* Separates the scene description (for image gen) from the caption text
* (for insertion below the image as HTML). Appends style suffix to the
* scene-only prompt so no text is rendered inside the image.
*
* @param array{
* post_title?: string,
@@ -75,18 +77,21 @@ PROMPT;
* suggested_title?: string,
* } $article_data Article data with title and HTML content.
*
* @return string Concise prompt with style suffix appended.
* @return array{prompt: string, caption: string} Image prompt (scene + style) and caption text.
*/
public function build_article_prompt( array $article_data ): string {
public function build_article_prompt( array $article_data ): array {
$title = $article_data['post_title'] ?? $article_data['suggested_title'] ?? 'Product';
$content = $article_data['post_content'] ?? '';
$first_para = $this->extract_first_paragraph( $content );
$concepts = $this->rewrite_via_llm( $title, $first_para );
$parsed = $this->rewrite_via_llm( $title, $first_para );
$style_suffix = get_option( 'prautoblogger_image_style_suffix', PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_SUFFIX );
return trim( $concepts . ' ' . $style_suffix );
return [
'prompt' => trim( $parsed['scene'] . ' ' . $style_suffix ),
'caption' => $parsed['caption'],
];
}
/**
@@ -101,22 +106,29 @@ PROMPT;
* comments?: string[],
* } $source_data Reddit source data with title and comments.
*
* @return string Concise prompt with style suffix appended.
* @return array{prompt: string, caption: string} Image prompt (scene + style) and caption text.
*/
public function build_source_prompt( array $source_data ): string {
public function build_source_prompt( array $source_data ): array {
$title = $source_data['title'] ?? 'Reddit Discussion';
$comments = $source_data['comments'] ?? [];
$context = is_array( $comments ) && ! empty( $comments ) ? $comments[0] : '';
$concepts = $this->rewrite_via_llm( $title, $context );
$parsed = $this->rewrite_via_llm( $title, $context );
$style_suffix = get_option( 'prautoblogger_image_style_suffix', PRAUTOBLOGGER_DEFAULT_IMAGE_STYLE_SUFFIX );
return trim( $concepts . ' ' . $style_suffix );
return [
'prompt' => trim( $parsed['scene'] . ' ' . $style_suffix ),
'caption' => $parsed['caption'],
];
}
/**
* Use a cheap LLM to distill title + context into a visual scene.
* Use a cheap LLM to distill title + context into a visual scene + caption.
*
* The LLM response contains a SCENE line and a CAPTION line separated by a
* blank line. This method parses them apart so the scene drives image gen
* (no text baked in) and the caption is inserted as HTML below the image.
*
* Falls back to rule-based synthesis if the LLM call fails for any
* reason (network, auth, timeout, unexpected response shape).
@@ -125,9 +137,9 @@ PROMPT;
*
* @param string $title Article or thread title.
* @param string $context First paragraph or top comment.
* @return string Visual scene description (without style suffix).
* @return array{scene: string, caption: string} Scene for image gen, caption for HTML.
*/
private function rewrite_via_llm( string $title, string $context ): string {
private function rewrite_via_llm( string $title, string $context ): array {
$title = trim( sanitize_text_field( $title ) );
$context = trim( sanitize_text_field( $context ) );
@@ -157,7 +169,7 @@ PROMPT;
]
);
$scene = trim( $result['content'] ?? '' );
$raw = trim( $result['content'] ?? '' );
// Log the rewrite cost so it shows in the analytics dashboard.
( new PRAutoBlogger_Cost_Tracker() )->log_api_call(
@@ -176,12 +188,12 @@ PROMPT;
);
PRAutoBlogger_Logger::instance()->debug(
sprintf( 'Image prompt rewritten (%d→%d chars, $%.6f): %s', strlen( $user_message ), strlen( $scene ), $cost, substr( $scene, 0, 120 ) ),
sprintf( 'Image prompt rewritten (%d→%d chars, $%.6f): %s', strlen( $user_message ), strlen( $raw ), $cost, substr( $raw, 0, 120 ) ),
'image_prompt_builder'
);
if ( '' !== $scene ) {
return $scene;
if ( '' !== $raw ) {
return $this->parse_scene_and_caption( $raw );
}
} catch ( \Throwable $e ) {
// LLM failure is not fatal — fall back to rule-based synthesis.
@@ -194,6 +206,36 @@ PROMPT;
return $this->synthesize_visual_concepts_fallback( $title, $context );
}
/**
* Parse the LLM response into separate scene and caption parts.
*
* Expected format from the LLM:
* Scene description text here.
*
* "Caption punchline here."
*
* Falls back gracefully: if no blank-line separator is found, the entire
* response becomes the scene with an empty caption.
*
* @param string $raw Raw LLM response text.
* @return array{scene: string, caption: string}
*/
private function parse_scene_and_caption( string $raw ): array {
// Split on blank line (the format the system prompt requests).
$parts = preg_split( '/\n\s*\n/', $raw, 2 );
if ( count( $parts ) >= 2 ) {
$scene = trim( $parts[0] );
$caption = trim( $parts[1] );
// Strip surrounding quotes from caption — the LLM wraps it in quotes.
$caption = trim( $caption, '"\'' );
return [ 'scene' => $scene, 'caption' => $caption ];
}
// No blank-line separator found — treat entire response as scene.
return [ 'scene' => trim( $raw ), 'caption' => '' ];
}
/**
* Extract the first paragraph from HTML content.
*
@@ -222,16 +264,19 @@ PROMPT;
*
* @param string $title Main heading / topic.
* @param string $supporting_text Additional context.
* @return string Synthesized visual prompt concept.
* @return array{scene: string, caption: string} Scene for image gen, caption for HTML.
*/
private function synthesize_visual_concepts_fallback( string $title, string $supporting_text ): string {
private function synthesize_visual_concepts_fallback( string $title, string $supporting_text ): array {
// Fallback produces a simple comic concept when the LLM is unavailable.
$prompt = sprintf(
'A cartoon scientist in a lab coat looking bewildered while examining something related to: %s. Caption below reads: "Science is full of surprises."',
$scene = sprintf(
'A cartoon scientist in a lab coat looking bewildered while examining something related to: %s.',
$title
);
return trim( $prompt );
return [
'scene' => trim( $scene ),
'caption' => 'Science is full of surprises.',
];
}
/**