Merge pull request #67639 from clayjohn/GLES3-2d-shadows

Add 2D shadows and canvas SDF to OpenGL3 renderer

1 files changed, 68 insertions, 0 deletions

diff --git a/drivers/gles3/shaders/canvas_occlusion.glsl b/drivers/gles3/shaders/canvas_occlusion.glsl
new file mode 100644
index 0000000000..512800839a
--- /dev/null
+++ b/drivers/gles3/shaders/canvas_occlusion.glsl
@@ -0,0 +1,68 @@
+/* clang-format off */
+#[modes]
+
+mode_sdf =
+mode_shadow = #define MODE_SHADOW
+mode_shadow_RGBA = #define MODE_SHADOW \n#define USE_RGBA_SHADOWS
+
+#[specializations]
+
+#[vertex]
+
+layout(location = 0) in vec3 vertex;
+
+uniform highp mat4 projection;
+uniform highp vec4 modelview1;
+uniform highp vec4 modelview2;
+uniform highp vec2 direction;
+uniform highp float z_far;
+
+#ifdef MODE_SHADOW
+out float depth;
+#endif
+
+void main() {
+	highp vec4 vtx = vec4(vertex, 1.0) * mat4(modelview1, modelview2, vec4(0.0, 0.0, 1.0, 0.0), vec4(0.0, 0.0, 0.0, 1.0));
+
+#ifdef MODE_SHADOW
+	depth = dot(direction, vtx.xy);
+#endif
+	gl_Position = projection * vtx;
+}
+
+#[fragment]
+
+
+uniform highp mat4 projection;
+uniform highp vec4 modelview1;
+uniform highp vec4 modelview2;
+uniform highp vec2 direction;
+uniform highp float z_far;
+
+#ifdef MODE_SHADOW
+in highp float depth;
+#endif
+
+#ifdef USE_RGBA_SHADOWS
+layout(location = 0) out lowp vec4 out_buf;
+#else
+layout(location = 0) out highp float out_buf;
+#endif
+
+void main() {
+    float out_depth = 1.0;
+
+#ifdef MODE_SHADOW
+	out_depth = depth / z_far;
+#endif
+
+#ifdef USE_RGBA_SHADOWS
+	out_depth = clamp(out_depth, -1.0, 1.0);
+	out_depth = out_depth * 0.5 + 0.5;
+	highp vec4 comp = fract(out_depth * vec4(255.0 * 255.0 * 255.0, 255.0 * 255.0, 255.0, 1.0));
+	comp -= comp.xxyz * vec4(0.0, 1.0 / 255.0, 1.0 / 255.0, 1.0 / 255.0);
+	out_buf = comp;
+#else
+	out_buf = out_depth;
+#endif
+}