Add bounds calculation to text

1 files changed, 51 insertions, 4 deletions

diff --git a/src/graphics/text.c b/src/graphics/text.c
index 723b37a..31ae794 100644
--- a/src/graphics/text.c
+++ b/src/graphics/text.c
@@ -11,6 +11,8 @@
     takes a while.
 */
 
+#define TAB_WIDTH 4
+
 static bool default_syntax_highlight(void *userdata, const char *str, size_t size, mgl_color *color) {
     (void)userdata;
     (void)str;
@@ -19,10 +21,42 @@ static bool default_syntax_highlight(void *userdata, const char *str, size_t siz
     return false;
 }
 
+static float fmax(float a, float b) {
+    return a >= b ? a : b;
+}
+
+static mgl_vec2f mgl_text_calculate_bounds(mgl_text *self) {
+    mgl_vec2f bounds;
+    bounds.x = 0.0f;
+    bounds.y = self->font->character_size;
+
+    /* TODO: Combine this with the loop in mgl_text_draw */
+    mgl_font_glyph glyph;
+    float width = 0.0f;
+    for(size_t i = 0; i < self->text_size; ++i) {
+        unsigned char c = *(unsigned char*)&self->text[i];
+        if((c >= 32 && c < 128)) {
+            if(mgl_font_get_glyph(self->font, c, &glyph) == 0) {
+                width += glyph.advance;
+                bounds.x = fmax(bounds.x, width);
+            }
+        } else if(c == '\t') {
+            if(mgl_font_get_glyph(self->font, ' ', &glyph) == 0) {
+                width += (glyph.advance * TAB_WIDTH);
+                bounds.x = fmax(bounds.x, width);
+            }
+        } else if(c == '\n') {
+            width = 0.0f;
+            bounds.y += self->font->character_size;
+        }
+    }
+
+    return bounds;
+}
+
 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 = str;
-    self->text_size = str_size;
+    mgl_text_set_string(self, str, str_size);
     self->color = (mgl_color){ 255, 255, 255, 255 };
     self->position = (mgl_vec2f){ 0.0f, 0.0f };
 
@@ -46,10 +80,20 @@ void mgl_text_deinit(mgl_text *self) {
 void mgl_text_set_string(mgl_text *self, const char *str, size_t str_size) {
     self->text = str;
     self->text_size = str_size;
+    if(self->text && self->text_size > 0 && self->font)
+        self->bounds = mgl_text_calculate_bounds(self);
+    else
+        self->bounds = (mgl_vec2f){ 0.0f, 0.0f };
 }
 
 void mgl_text_set_font(mgl_text *self, mgl_font *font) {
     self->font = font;
+    if(self->font) {
+        if(self->bounds.x < 0.001f && self->bounds.y < 0.001f)
+            self->bounds = mgl_text_calculate_bounds(self);
+    } else {
+        self->bounds = (mgl_vec2f){ 0.0f, 0.0f };
+    }
 }
 
 void mgl_text_set_position(mgl_text *self, mgl_vec2f position) {
@@ -60,6 +104,10 @@ void mgl_text_set_color(mgl_text *self, mgl_color color) {
     self->color = color;
 }
 
+mgl_vec2f mgl_text_get_bounds(const mgl_text *self) {
+    return self->bounds;
+}
+
 static void mgl_text_draw_glyph(mgl_context *context, mgl_font_glyph *glyph, mgl_vec2f position) {
     context->gl.glTexCoord2f(glyph->texture_position.x, glyph->texture_position.y);
     context->gl.glVertex3f(position.x + glyph->position.x, position.y + glyph->position.y, 0.0f);
@@ -116,8 +164,7 @@ void mgl_text_draw(mgl_context *context, mgl_text *text) {
             }
         } else if(c == '\t') {
             if(mgl_font_get_glyph(text->font, ' ', &glyph) == 0) {
-                const int tab_width = 4;
-                for(int i = 0; i < tab_width; ++i) {
+                for(int i = 0; i < TAB_WIDTH; ++i) {
                     mgl_text_draw_glyph(context, &glyph, position);
                     position.x += glyph.advance;
                 }