tweak renderer API

resources/shaders/source/font.frag.glsl

@@ -0,0 +1,21 @@
+#version 450
+
+layout(set = 3, binding = 0) uniform Viewport {
+    ivec2 view;
+};
+layout(set = 2, binding = 0) uniform sampler2D tx;
+
+layout(location = 0) in vec2 uv;
+layout(location = 1) in vec4 color;
+
+layout(location = 0) out vec4 fragColor;
+
+void main()
+{
+    ivec2 ts = textureSize(tx, 0);
+    vec2 fts = vec2(float(ts.x), float(ts.y));
+    vec2 real_uv = uv / fts;
+
+    vec4 opacity = texture(tx, real_uv);
+    fragColor = vec4(color.rgb, color.a*opacity.r);
+}

resources/shaders/source/msdf.frag.glsl

@@ -0,0 +1,35 @@
+#version 450
+
+layout(set = 3, binding = 0) uniform Viewport {
+    ivec2 view;
+};
+layout(set = 2, binding = 0) uniform sampler2D tx;
+
+const float PX_RANGE = 4.0f;
+
+layout(location = 0) in vec2 uv;
+layout(location = 1) in vec4 color;
+
+layout(location = 0) out vec4 fragColor;
+
+float screen_px_range(vec2 uv) {
+    vec2 unit_range = vec2(PX_RANGE)/vec2(textureSize(tx, 0));
+    vec2 texel_size = vec2(1.0)/fwidth(uv);
+    return max(0.5*dot(unit_range, texel_size), 1.0);
+}
+
+float median(float r, float g, float b) {
+	return max(min(r, g), min(max(r, g), b));
+}
+
+void main() {
+    ivec2 ts = textureSize(tx, 0);
+    vec2 fts = vec2(float(ts.x), float(ts.y));
+    vec2 real_uv = uv / fts;
+
+	vec3 msd = texture(tx, real_uv).rgb;
+	float sd = median(msd.r, msd.g, msd.b);
+	float distance = screen_px_range(real_uv)*(sd - 0.5);
+	float opacity = clamp(distance + 0.5, 0.0, 1.0);
+	fragColor = color * opacity;
+}

resources/shaders/source/rect.frag.glsl

@@ -1,5 +1,9 @@
 #version 450
 
+layout(set = 3, binding = 0) uniform Viewport {
+    ivec2 view;
+};
+
 layout(location = 0) in vec4 color;
 layout(location = 1) in vec2 local_position;
 layout(location = 2) in vec2 global_position;

resources/shaders/source/rect.vert.glsl

@@ -2,7 +2,6 @@
 
 layout(set = 1, binding = 0) uniform Viewport {
 	ivec2 view;
-	ivec2 off;
 };
 
 layout(location = 0) in ivec2 position;
@@ -16,17 +15,12 @@ layout(location = 3) out float radius;
 
 void main()
 {
-	// per vertex shift
-	vec2 shift;
-	shift.x = float(off.x) / view.x;
-	shift.y = -(float(off.y) / view.y);
-
 	// vertex position
 	vec2 pos;
 	pos.x = float(position.x)*2.0 / view.x - 1.0;
 	pos.y = -(float(position.y)*2.0 / view.y - 1.0);
 
-	gl_Position = vec4(pos+shift, 0.0, 1.0);
+	gl_Position = vec4(pos, 0.0, 1.0);
 
 	local_position = vec2(sign(uv));
 	global_position = gl_Position.xy;

resources/shaders/source/sprite.frag.glsl

@@ -1,5 +1,9 @@
 #version 450
 
+layout(set = 3, binding = 0) uniform Viewport {
+    ivec2 view;
+};
+
 layout(location = 0) in vec2 uv;
 layout(location = 0) out vec4 fragColor;
 

resources/shaders/source/sprite.vert.glsl

@@ -2,7 +2,6 @@
 
 layout(set = 1, binding = 0) uniform Viewport {
     ivec2 view;
-    ivec2 not_needed;
 };
 
 layout(location = 0) in ivec2 position;
@@ -10,6 +9,7 @@ layout(location = 1) in ivec2 in_uv;
 layout(location = 2) in ivec4 color;
 
 layout(location = 0) out vec2 out_uv;
+layout(location = 1) out vec4 out_color;
 
 void main()
 {
@@ -19,4 +19,5 @@ void main()
 	gl_Position = vec4(pos, 0.0, 1.0);
 
     out_uv = vec2(float(in_uv.x), float(in_uv.y));
+    out_color = vec4(color) / 255.0;
 }