Add gradient text effect

include/cute_draw.h

@@ -963,6 +963,12 @@ typedef struct CF_TextEffect
 	/* @member User-modifiable. The color to render this glyph with. */
 	CF_Color color;
 
+	/* @member User-modifiable. Per-corner colors: [0]=TL, [1]=TR, [2]=BR, [3]=BL. Only used when use_colors is true. */
+	CF_Color colors[4];
+
+	/* @member User-modifiable. If true, use colors[4] per-corner instead of flat color. */
+	bool use_colors;
+
 	/* @member User-modifiable. The opacity to render this glyph with. */
 	float opacity;
 

samples/text_drawing.cpp

@@ -21,7 +21,7 @@ static void draw_text_boxed(const char* text, v2 pos, int len = -1)
 
 int main(int argc, char* argv[])
 {
-	make_app("Text Drawing", 0, 0, 0, 640, 480, CF_APP_OPTIONS_WINDOW_POS_CENTERED_BIT | CF_APP_OPTIONS_RESIZABLE_BIT, argv[0]);
+	make_app("Text Drawing", 0, 0, 0, 960, 700, CF_APP_OPTIONS_WINDOW_POS_CENTERED_BIT | CF_APP_OPTIONS_RESIZABLE_BIT, argv[0]);
 
 	draw_push_shape_aa(1.5f);
 	make_font_from_memory(proggy_data, proggy_sz, "ProggyClean");
@@ -95,7 +95,7 @@ int main(int argc, char* argv[])
 		// Drawing a formatted string.
 		String draws = String::fmt("Draw calls: %d", draw_calls);
 		push_font_size(13);
-		draw_text_boxed(draws.c_str(), V2(-640/2.0f + 10,-480/2.0f + 20));
+		draw_text_boxed(draws.c_str(), V2(-960/2.0f + 10,-700/2.0f + 20));
 
 		push_font_size(26);
 		draw_text_boxed("Half-rendered effect <wave>groovy</wave>", V2(-230.f, 180.f), 25);
@@ -107,6 +107,33 @@ int main(int argc, char* argv[])
 		draw_text_boxed("Some <shake freq=35 x=2 y=2>shaking</shake> text.", round(V2(sinf((float)CF_SECONDS*0.25f)*100,cosf((float)CF_SECONDS*0.25f)*100)));
 
 
+		float gx = 130;
+
+		// Horizontal: left-to-right red to blue.
+		push_font_size(30);
+		draw_text_boxed("<gradient left=#ff0000 right=#0055ff>Left-to-right gradient!</gradient>", V2(gx, -80));
+
+		// Vertical: top gold to bottom purple.
+		push_font_size(30);
+		draw_text_boxed("<gradient top=#ffd700 bottom=#8b00ff>Top-to-bottom gradient!</gradient>", V2(gx, -120));
+
+		// Corners: direct per-corner control.
+		push_font_size(30);
+		draw_text_boxed("<gradient topleft=#ff0000 topright=#00ff00 bottomright=#0000ff bottomleft=#ffff00>Per-corner colors</gradient>", V2(gx, -160));
+
+		// Mix: edge + corner override.
+		push_font_size(30);
+		draw_text_boxed("<gradient left=#ff0000 right=#0000ff topleft=#00ff00>Edge + corner override</gradient>", V2(gx, -200));
+
+		// Single edge: fades from red to the glyph's current color.
+		push_font_size(30);
+		draw_text_boxed("<gradient left=#ff0000>Fade from one color</gradient>", V2(gx, -240));
+
+		// Short strings: gradient should still work on 1-2 glyphs.
+		push_font_size(40);
+		draw_text_boxed("<gradient left=#ff0000 right=#0000ff>AB</gradient>", V2(gx, -280));
+		draw_text_boxed("<gradient top=#ff0000 bottom=#0000ff>X</gradient>", V2(gx + 80, -280));
+
 		cf_push_text_id(1);
 		{
 			char text_buf[512];

src/cute_draw.cpp

@@ -237,14 +237,28 @@ static void s_draw_report(spritebatch_sprite_t* sprites, int count, int texture_
 				} else {
 					CF_ASSERT(false);
 				}
-				out[i].color = s->geom.color;
 				out[i].attributes = geom.user_params;
 				out[i].uv_bounds[0] = s->minx;
 				out[i].uv_bounds[1] = s->maxy; // y-flip.
 				out[i].uv_bounds[2] = s->maxx;
 				out[i].uv_bounds[3] = s->miny; // y-flip.
 			}
 
+			// Per-vertex colors: text uses per-corner text_colors, sprites use flat color.
+			// shape[0]=TL, shape[1]=TR, shape[2]=BR, shape[3]=BL
+			// Triangle 1: TL(0), BL(3), TR(1)  Triangle 2: TR(1), BL(3), BR(2)
+			if (s->geom.is_text) {
+				CF_Pixel *tc = s->geom.text_colors;
+				out[0].color = tc[0]; // TL
+				out[1].color = tc[3]; // BL
+				out[2].color = tc[1]; // TR
+				out[3].color = tc[1]; // TR
+				out[4].color = tc[3]; // BL
+				out[5].color = tc[2]; // BR
+			} else {
+				for (int i = 0; i < 6; ++i) out[i].color = s->geom.color;
+			}
+
 			out[0].posH = geom.shape[0];
 			out[0].uv.x = s->minx;
 			out[0].uv.y = s->maxy;
@@ -2266,12 +2280,12 @@ static CF_Color s_parse_color(CF_CodeParseState* s)
 	String string;
 	s->expect('#');
 	while (!s->done()) {
-		int cp = s->peek();
+		int cp = s->peek(false);
 		if (!s_is_hex_alphanum(cp)) {
 			break;
 		} else {
 			string.append(cp);
-			s->skip();
+			s->skip(false);
 		}
 	}
 	uint32_t rgba = 0x000000FF;
@@ -2458,6 +2472,39 @@ static bool s_text_fx_strike(CF_TextEffect* fx_ptr)
 	return true;
 }
 
+static CF_Color s_gradient_corner(TextEffect* fx, const char* corner, const char* edge_a, const char* edge_b)
+{
+	CF_Color c = fx->color;
+	if (fx->has(corner)) return fx->get_color(corner, c);
+	bool a = fx->has(edge_a);
+	bool b = fx->has(edge_b);
+	if (a && b) return cf_color_lerp(fx->get_color(edge_a, c), fx->get_color(edge_b, c), 0.5f);
+	if (a) return fx->get_color(edge_a, c);
+	if (b) return fx->get_color(edge_b, c);
+	return c;
+}
+
+static bool s_text_fx_gradient(CF_TextEffect* fx_ptr)
+{
+	TextEffect* fx = (TextEffect*)fx_ptr;
+
+	CF_Color tl = s_gradient_corner(fx, "topleft",     "top",    "left");
+	CF_Color tr = s_gradient_corner(fx, "topright",    "top",    "right");
+	CF_Color br = s_gradient_corner(fx, "bottomright", "bottom", "right");
+	CF_Color bl = s_gradient_corner(fx, "bottomleft",  "bottom", "left");
+
+	float n = (float)fx->glyph_count;
+	float t_left = (float)fx->index_into_effect / n;
+	float t_right = (float)(fx->index_into_effect + 1) / n;
+
+	fx->use_colors = true;
+	fx->colors[0] = cf_color_lerp(tl, tr, t_left);   // glyph TL
+	fx->colors[1] = cf_color_lerp(tl, tr, t_right);  // glyph TR
+	fx->colors[2] = cf_color_lerp(bl, br, t_right);  // glyph BR
+	fx->colors[3] = cf_color_lerp(bl, br, t_left);   // glyph BL
+	return true;
+}
+
 static void s_parse_codes(CF_ParsedTextState* text_state, const char* text)
 {
 	// Register built-in text effects.
@@ -2469,6 +2516,7 @@ static void s_parse_codes(CF_ParsedTextState* text_state, const char* text)
 		text_effect_register("fade", s_text_fx_fade);
 		text_effect_register("wave", s_text_fx_wave);
 		text_effect_register("strike", s_text_fx_strike);
+		text_effect_register("gradient", s_text_fx_gradient);
 	}
 
 	CF_CodeParseState state = { };
@@ -2715,6 +2763,7 @@ static v2 s_draw_text(const char* text, CF_V2 position, int text_length, bool re
 			v2 q1 = glyph->q1 + V2(x,y) + kern + pad;
 
 			// Apply any active custom text effects.
+			bool use_corner_colors = false;
 			for (int i = 0; i < text_state->effects.count();) {
 				TextEffect* effect = text_state->effects + i;
 				CF_TextEffectFn* fn = effect->fn;
@@ -2729,6 +2778,7 @@ static v2 s_draw_text(const char* text, CF_V2 position, int text_length, bool re
 					effect->w = s.w;
 					effect->h = s.h;
 					effect->color = color;
+					effect->use_colors = false;
 					effect->opacity = s.geom.alpha;
 					effect->xadvance = xadvance;
 					effect->visible = visible;
@@ -2738,6 +2788,13 @@ static v2 s_draw_text(const char* text, CF_V2 position, int text_length, bool re
 					q0 = effect->q0;
 					q1 = effect->q1;
 					color = effect->color;
+					if (effect->use_colors) {
+						use_corner_colors = true;
+						s.geom.text_colors[0] = premultiply(to_pixel(effect->colors[0]));
+						s.geom.text_colors[1] = premultiply(to_pixel(effect->colors[1]));
+						s.geom.text_colors[2] = premultiply(to_pixel(effect->colors[2]));
+						s.geom.text_colors[3] = premultiply(to_pixel(effect->colors[3]));
+					}
 					s.geom.alpha = effect->opacity;
 					xadvance = effect->xadvance;
 					visible = effect->visible;
@@ -2774,6 +2831,10 @@ static v2 s_draw_text(const char* text, CF_V2 position, int text_length, bool re
 				CF_MUL_M32_V2(s.geom.shape[2], m, V2(q1.x, q0.y));
 				CF_MUL_M32_V2(s.geom.shape[3], m, V2(q0.x, q0.y));
 				s.geom.color = premultiply(to_pixel(color));
+				if (!use_corner_colors) {
+					CF_Pixel flat = s.geom.color;
+					for (int j = 0; j < 4; ++j) s.geom.text_colors[j] = flat;
+				}
 				s.geom.is_text = true;
 				DRAW_PUSH_ITEM(s);
 			}

src/internal/cute_draw_internal.h

@@ -43,6 +43,7 @@ struct BatchGeometry
 	float aa;
 	bool is_text;
 	bool is_sprite;
+	CF_Pixel text_colors[4]; // Per-corner: TL, TR, BR, BL (for text glyphs)
 	bool fill;
 	bool use_tri_colors;      // Per-vertex colors for triangles.
 	bool use_tri_attributes;  // Per-vertex attributes for triangles.

src/internal/cute_font_internal.h

@@ -62,6 +62,7 @@ struct TextEffect : public CF_TextEffect
 {
 	CF_INLINE bool on_start() const { return index_into_effect == 0; }
 	CF_INLINE bool on_finish() const { return index_into_effect == glyph_count - 1; }
+	CF_INLINE bool has(const char* key) const { return params->try_find(sintern(key)) != NULL; }
 
 	CF_INLINE double get_number(const char* key, double default_val = 0) const
 	{