Implement DrawGraph.BlendUseAMapColor

include/gfx/gfx.h

@@ -120,6 +120,7 @@ void gfx_blend_amap_color_alpha(Texture *dst, int dx, int dy, Texture *src, int
 void gfx_blend_amap_alpha(struct texture *dst, int dx, int dy, struct texture *src, int sx, int sy, int w, int h, int a);
 void gfx_blend_amap_bright(Texture *dst, int dx, int dy, Texture *src, int sx, int sy, int w, int h, int rate);
 void gfx_blend_amap_alpha_src_bright(Texture *dst, int dx, int dy, Texture *src, int sx, int sy, int w, int h, int alpha, int rate);
+void gfx_blend_use_amap_color(Texture *dst, int dx, int dy, Texture *src, int sx, int sy, int w, int h, int r, int g, int b, int rate);
 void gfx_fill(struct texture *dst, int x, int y, int w, int h, int r, int g, int b);
 void gfx_fill_alpha_color(struct texture *dst, int x, int y, int w, int h, int r, int g, int b, int a);
 void gfx_fill_amap(struct texture *dst, int x, int y, int w, int h, int a);

shaders/blend_use_amap_color.f.glsl

@@ -0,0 +1,31 @@
+/* Copyright (C) 2019 Nunuhara Cabbage <nunuhara@haniwa.technology>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://gnu.org/licenses/>.
+ */
+
+uniform sampler2D tex;
+uniform float threshold;
+uniform vec4 color;
+
+in vec2 tex_coord;
+out vec4 frag_color;
+
+void main() {
+	// alpha values at or above `rate + 16` get an alpha of 0
+	// alpha values below `rate` get an alpha of 255
+	// alpha values between `rate` and `rate + 16` are blended
+	float delta = texture(tex, tex_coord).a - threshold;
+	float alpha = 1.0 - clamp(delta * 16.0, 0.0, 1.0);
+	frag_color = vec4(color.rgb, alpha);
+}

src/draw.c

@@ -64,6 +64,7 @@ static struct copy_shader copy_use_amap_under_shader;
 static struct copy_shader copy_use_amap_border_shader;
 static struct copy_shader blend_amap_color_shader;
 static struct copy_shader blend_amap_alpha_bright_shader;
+static struct copy_shader blend_use_amap_color_shader;
 static struct copy_shader fill_shader;
 static struct copy_shader fill_amap_over_border_shader;
 static struct copy_shader fill_amap_under_border_shader;
@@ -119,6 +120,8 @@ void gfx_draw_init(void)
 	// copy shader that multiples the source color and alpha by a constant
 	load_copy_shader(&blend_amap_alpha_bright_shader, "shaders/render.v.glsl", "shaders/blend_amap_alpha_bright.f.glsl");
 
+	load_copy_shader(&blend_use_amap_color_shader, "shaders/render.v.glsl", "shaders/blend_use_amap_color.f.glsl");
+
 	// basic fill shader
 	load_copy_shader(&fill_shader, "shaders/render.v.glsl", "shaders/fill.f.glsl");
 
@@ -425,6 +428,22 @@ void gfx_blend_amap_alpha_src_bright(Texture *dst, int dx, int dy, Texture *src,
 	restore_blend_mode();
 }
 
+void gfx_blend_use_amap_color(Texture *dst, int dx, int dy, Texture *src, int sx, int sy, int w, int h, int r, int g, int b, int rate)
+{
+	glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ZERO, GL_ONE);
+
+	struct copy_data data = COPY_DATA(dx, dy, sx, sy, w, h);
+	data.r = r / 255.0;
+	data.g = g / 255.0;
+	data.b = b / 255.0;
+	data.a = 1.0;
+	data.threshold = rate / 255.0;
+	run_copy_shader(&blend_use_amap_color_shader.s, dst, src, &data);
+
+	restore_blend_mode();
+
+}
+
 void gfx_fill(Texture *dst, int x, int y, int w, int h, int r, int g, int b)
 {
 	glBlendFuncSeparate(GL_ONE, GL_ZERO, GL_ZERO, GL_ONE);

src/hll/DrawGraph.c

@@ -131,7 +131,11 @@ static void DrawGraph_BlendAMapAlphaSrcBright(int dst, int dx, int dy, int src,
 	gfx_blend_amap_alpha_src_bright(DTEX(dst), dx, dy, STEX(src), sx, sy, w, h, alpha, rate);
 }
 
-//void DrawGraph_BlendUseAMapColor(int dst, int dx, int dy, int alpha, int ax, int ay, int w, int h, int r, int g, int b, int rate);
+static void DrawGraph_BlendUseAMapColor(int dst, int dx, int dy, int alpha, int ax, int ay, int w, int h, int r, int g, int b, int rate)
+{
+	gfx_blend_use_amap_color(DTEX(dst), dx, dy, STEX(alpha), ax, ay, w, h, r, g, b, rate);
+}
+
 //void DrawGraph_BlendScreen(int dst, int dx, int dy, int src, int sx, int sy, int w, int h);
 //void DrawGraph_BlendMultiply(int dst, int dx, int dy, int src, int sx, int sy, int w, int h);
 //void DrawGraph_BlendScreenAlpha(int dst, int dx, int dy, int src, int sx, int sy, int w, int h, int alpha);
@@ -381,7 +385,7 @@ HLL_LIBRARY(DrawGraph,
 	    HLL_EXPORT(BlendAMapAlpha, DrawGraph_BlendAMapAlpha),
 	    HLL_EXPORT(BlendAMapBright, DrawGraph_BlendAMapBright),
 	    HLL_EXPORT(BlendAMapAlphaSrcBright, DrawGraph_BlendAMapAlphaSrcBright),
-	    //HLL_EXPORT(BlendUseAMapColor, DrawGraph_BlendUseAMapColor),
+	    HLL_EXPORT(BlendUseAMapColor, DrawGraph_BlendUseAMapColor),
 	    //HLL_EXPORT(BlendScreen, DrawGraph_BlendScreen),
 	    //HLL_EXPORT(BlendMultiply, DrawGraph_BlendMultiply),
 	    //HLL_EXPORT(BlendScreenAlpha, DrawGraph_BlendScreenAlpha),