From 111f0ba3f4a4f14d39c8e3f7c00f13e852f47a51 Mon Sep 17 00:00:00 2001
From: dec05eba <dec05eba@protonmail.com>
Date: Sun, 31 Oct 2021 12:50:05 +0100
Subject: Start on syntax highlighting, output correct key button event

---
 src/graphics/text.c | 67 ++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 56 insertions(+), 11 deletions(-)

(limited to 'src/graphics/text.c')

diff --git a/src/graphics/text.c b/src/graphics/text.c
index 76fd852..9a849a9 100644
--- a/src/graphics/text.c
+++ b/src/graphics/text.c
@@ -2,20 +2,48 @@
 #include "../../include/mgl/graphics/font.h"
 #include "../../include/mgl/mgl.h"
 
-int mgl_text_init(mgl_text *self, mgl_font *font, const char *text, float x, float y) {
+/*
+    TODO: Do syntax highlight in constructor/mgl_text_set_string for optimization.
+    Syntax highlighting should the first text that is visible in the text editor and find the start and end,
+    and start syntax highlight from there until the last visible text.
+    In that case there should also be a function to rerun the syntax highlighting, to update it
+    when an asynchronous process finishes that parses code, such as a lsp client parsing C++ code which
+    takes a while.
+*/
+
+static bool default_syntax_highlight(void *userdata, const char *str, size_t size, mgl_color *color) {
+    (void)userdata;
+    (void)str;
+    (void)size;
+    (void)color;
+    return false;
+}
+
+int mgl_text_init(mgl_text *self, mgl_font *font, const char *str, size_t str_size, mgl_text_options *options) {
     self->font = font;
-    self->text = text;
+    self->text = str;
+    self->text_size = str_size;
     self->color = (mgl_color){ 255, 255, 255, 255 };
-    self->position = (mgl_vec2f){ x, y };
+    self->position = (mgl_vec2f){ 0.0f, 0.0f };
+
+    if(options)
+        self->options = *options;
+    else
+        self->options.userdata = NULL;
+
+    if(!options || !options->syntax_highlight)
+        self->options.syntax_highlight = default_syntax_highlight;
+
     return 0;
 }
 
 void mgl_text_deinit(mgl_text *self) {
-
+    (void)self;
 }
 
-void mgl_text_set_string(mgl_text *self, const char *str) {
+void mgl_text_set_string(mgl_text *self, const char *str, size_t str_size) {
     self->text = str;
+    self->text_size = str_size;
 }
 
 void mgl_text_set_font(mgl_text *self, mgl_font *font) {
@@ -44,25 +72,43 @@ static void mgl_text_draw_glyph(mgl_context *context, mgl_font_glyph *glyph, mgl
     context->gl.glVertex3f(position.x + glyph->position.x, position.y + glyph->position.y + glyph->size.y, 0.0f);
 }
 
+static void mgl_text_run_syntax_highlight(mgl_context *context, mgl_text *text, const char *str, size_t size, mgl_color *color, bool *color_changed) {
+    if(text->options.syntax_highlight(text->options.userdata, str, size, color)) {
+        context->gl.glColor4ub(color->r, color->g, color->b, color->a);
+        *color_changed = true;
+    } else {
+        if(*color_changed) {
+            *color = text->color;
+            context->gl.glColor4ub(color->r, color->g, color->b, color->a);
+            *color_changed = false;
+        }
+    }
+}
+
 /* TODO: Use opengl buffer object instead */
 /* TODO: Cache texture bind to not bind texture if its already bound and do not bind texture 0 */
 void mgl_text_draw(mgl_context *context, mgl_text *text) {
-    if(!text->text || !text->font)
+    if(!text->text || text->text_size == 0 || !text->font)
         return;
 
-    const char *str = text->text;
-
     mgl_font_glyph glyph;
     mgl_vec2f position = text->position;
     position.y += text->font->character_size;
 
+    mgl_color color = text->color;
+    bool color_changed = false;
+
+    if(text->options.before_syntax_highlight)
+        text->options.before_syntax_highlight(text->options.userdata);
+
     context->gl.glColor4ub(text->color.r, text->color.g, text->color.b, text->color.a);
     context->gl.glBindTexture(GL_TEXTURE_2D, text->font->texture.id);
     context->gl.glBegin(GL_QUADS);
-    while(*str) {
-        unsigned char c = *(unsigned char*)str;
+    for(size_t i = 0; i < text->text_size; ++i) {
+        unsigned char c = *(unsigned char*)&text->text[i];
         if((c >= 32 && c < 128)) {
             if(mgl_font_get_glyph(text->font, c, &glyph) == 0) {
+                mgl_text_run_syntax_highlight(context, text, (const char*)&c, 1, &color, &color_changed);
                 mgl_text_draw_glyph(context, &glyph, position);
                 position.x += glyph.advance;
             }
@@ -78,7 +124,6 @@ void mgl_text_draw(mgl_context *context, mgl_text *text) {
             position.x = text->position.x;
             position.y += text->font->character_size;
         }
-        ++str;
     }
     context->gl.glEnd();
     context->gl.glBindTexture(GL_TEXTURE_2D, 0);
-- 
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