Merge pull request #69325 from clayjohn/GLES3-skeletons

Add Skeletons and Blend Shapes to the OpenGL renderer

3 files changed, 270 insertions, 9 deletions

diff --git a/drivers/gles3/shaders/SCsub b/drivers/gles3/shaders/SCsub
index 2686b1aa48..34713e7e29 100644
--- a/drivers/gles3/shaders/SCsub
+++ b/drivers/gles3/shaders/SCsub
@@ -21,3 +21,4 @@ if "GLES3_GLSL" in env["BUILDERS"]:
     env.GLES3_GLSL("canvas_sdf.glsl")
     env.GLES3_GLSL("particles.glsl")
     env.GLES3_GLSL("particles_copy.glsl")
+    env.GLES3_GLSL("skeleton.glsl")
diff --git a/drivers/gles3/shaders/canvas.glsl b/drivers/gles3/shaders/canvas.glsl
index cdae05a516..60139de472 100644
--- a/drivers/gles3/shaders/canvas.glsl
+++ b/drivers/gles3/shaders/canvas.glsl
@@ -19,9 +19,6 @@ layout(location = 0) in vec2 vertex_attrib;
 layout(location = 3) in vec4 color_attrib;
 layout(location = 4) in vec2 uv_attrib;
 
-layout(location = 10) in uvec4 bone_attrib;
-layout(location = 11) in vec4 weight_attrib;
-
 #ifdef USE_INSTANCING
 
 layout(location = 1) in highp vec4 instance_xform0;
@@ -81,8 +78,6 @@ void main() {
 		uv = draw_data[draw_data_instance].uv_c;
 		color = vec4(unpackHalf2x16(draw_data[draw_data_instance].color_c_rg), unpackHalf2x16(draw_data[draw_data_instance].color_c_ba));
 	}
-	uvec4 bones = uvec4(0, 0, 0, 0);
-	vec4 bone_weights = vec4(0.0);
 
 #elif defined(USE_ATTRIBUTES)
 	draw_data_instance = gl_InstanceID;
@@ -93,9 +88,6 @@ void main() {
 	vec4 color = color_attrib * draw_data[draw_data_instance].modulation;
 	vec2 uv = uv_attrib;
 
-	uvec4 bones = bone_attrib;
-	vec4 bone_weights = weight_attrib;
-
 #ifdef USE_INSTANCING
 	vec4 instance_color = vec4(unpackHalf2x16(instance_color_custom_data.x), unpackHalf2x16(instance_color_custom_data.y));
 	color *= instance_color;
@@ -110,7 +102,6 @@ void main() {
 	vec2 uv = draw_data[draw_data_instance].src_rect.xy + abs(draw_data[draw_data_instance].src_rect.zw) * ((draw_data[draw_data_instance].flags & FLAGS_TRANSPOSE_RECT) != uint(0) ? vertex_base.yx : vertex_base.xy);
 	vec4 color = draw_data[draw_data_instance].modulation;
 	vec2 vertex = draw_data[draw_data_instance].dst_rect.xy + abs(draw_data[draw_data_instance].dst_rect.zw) * mix(vertex_base, vec2(1.0, 1.0) - vertex_base, lessThan(draw_data[draw_data_instance].src_rect.zw, vec2(0.0, 0.0)));
-	uvec4 bones = uvec4(0, 0, 0, 0);
 
 #endif
 
diff --git a/drivers/gles3/shaders/skeleton.glsl b/drivers/gles3/shaders/skeleton.glsl
new file mode 100644
index 0000000000..a1e3c098f4
--- /dev/null
+++ b/drivers/gles3/shaders/skeleton.glsl
@@ -0,0 +1,269 @@
+/* clang-format off */
+#[modes]
+
+mode_base_pass =
+mode_blend_pass = #define MODE_BLEND_PASS
+
+#[specializations]
+
+MODE_2D = true
+USE_BLEND_SHAPES = false
+USE_SKELETON = false
+USE_NORMAL = false
+USE_TANGENT = false
+FINAL_PASS = false
+USE_EIGHT_WEIGHTS = false
+
+#[vertex]
+
+#include "stdlib_inc.glsl"
+
+#ifdef MODE_2D
+#define VFORMAT vec2
+#else
+#define VFORMAT vec3
+#endif
+
+#ifdef FINAL_PASS
+#define OFORMAT vec2
+#else
+#define OFORMAT uvec2
+#endif
+
+// These come from the source mesh and the output from previous passes.
+layout(location = 0) in highp VFORMAT in_vertex;
+#ifdef MODE_BLEND_PASS
+#ifdef USE_NORMAL
+layout(location = 1) in highp uvec2 in_normal;
+#endif
+#ifdef USE_TANGENT
+layout(location = 2) in highp uvec2 in_tangent;
+#endif
+#else // MODE_BLEND_PASS
+#ifdef USE_NORMAL
+layout(location = 1) in highp vec2 in_normal;
+#endif
+#ifdef USE_TANGENT
+layout(location = 2) in highp vec2 in_tangent;
+#endif
+#endif // MODE_BLEND_PASS
+
+#ifdef USE_SKELETON
+#ifdef USE_EIGHT_WEIGHTS
+layout(location = 10) in highp uvec4 in_bone_attrib;
+layout(location = 11) in highp uvec4 in_bone_attrib2;
+layout(location = 12) in mediump vec4 in_weight_attrib;
+layout(location = 13) in mediump vec4 in_weight_attrib2;
+#else
+layout(location = 10) in highp uvec4 in_bone_attrib;
+layout(location = 11) in mediump vec4 in_weight_attrib;
+#endif
+
+uniform mediump sampler2D skeleton_texture; // texunit:0
+#endif
+
+/* clang-format on */
+#ifdef MODE_BLEND_PASS
+layout(location = 3) in highp VFORMAT blend_vertex;
+#ifdef USE_NORMAL
+layout(location = 4) in highp vec2 blend_normal;
+#endif
+#ifdef USE_TANGENT
+layout(location = 5) in highp vec2 blend_tangent;
+#endif
+#endif // MODE_BLEND_PASS
+
+out highp VFORMAT out_vertex; //tfb:
+
+#ifdef USE_NORMAL
+flat out highp OFORMAT out_normal; //tfb:USE_NORMAL
+#endif
+#ifdef USE_TANGENT
+flat out highp OFORMAT out_tangent; //tfb:USE_TANGENT
+#endif
+
+#ifdef USE_BLEND_SHAPES
+uniform highp float blend_weight;
+uniform lowp float blend_shape_count;
+#endif
+
+vec2 signNotZero(vec2 v) {
+	return mix(vec2(-1.0), vec2(1.0), greaterThanEqual(v.xy, vec2(0.0)));
+}
+
+vec3 oct_to_vec3(vec2 oct) {
+	oct = oct * 2.0 - 1.0;
+	vec3 v = vec3(oct.xy, 1.0 - abs(oct.x) - abs(oct.y));
+	if (v.z < 0.0) {
+		v.xy = (1.0 - abs(v.yx)) * signNotZero(v.xy);
+	}
+	return normalize(v);
+}
+
+vec2 vec3_to_oct(vec3 e) {
+	e /= abs(e.x) + abs(e.y) + abs(e.z);
+	vec2 oct = e.z >= 0.0f ? e.xy : (vec2(1.0f) - abs(e.yx)) * signNotZero(e.xy);
+	return oct * 0.5f + 0.5f;
+}
+
+vec4 oct_to_tang(vec2 oct_sign_encoded) {
+	// Binormal sign encoded in y component
+	vec2 oct = vec2(oct_sign_encoded.x, abs(oct_sign_encoded.y) * 2.0 - 1.0);
+	return vec4(oct_to_vec3(oct), sign(oct_sign_encoded.y));
+}
+
+vec2 tang_to_oct(vec4 base) {
+	vec2 oct = vec3_to_oct(base.xyz);
+	// Encode binormal sign in y component
+	oct.y = oct.y * 0.5f + 0.5f;
+	oct.y = base.w >= 0.0f ? oct.y : 1.0 - oct.y;
+	return oct;
+}
+
+// Our original input for normals and tangents is 2 16-bit floats.
+// Transform Feedback has to write out 32-bits per channel.
+// Octahedral compression requires normalized vectors, but we need to store
+// non-normalized vectors until the very end.
+// Therefore, we will compress our normals into 16 bits using signed-normalized
+// fixed point precision. This works well, because we know that each normal
+// is no larger than |1| so we can normalize by dividing by the number of blend
+// shapes.
+uvec2 vec4_to_vec2(vec4 p_vec) {
+	return uvec2(packSnorm2x16(p_vec.xy), packSnorm2x16(p_vec.zw));
+}
+
+vec4 vec2_to_vec4(uvec2 p_vec) {
+	return vec4(unpackSnorm2x16(p_vec.x), unpackSnorm2x16(p_vec.y));
+}
+
+void main() {
+#ifdef MODE_2D
+	out_vertex = in_vertex;
+
+#ifdef USE_BLEND_SHAPES
+#ifdef MODE_BLEND_PASS
+	out_vertex = in_vertex + blend_vertex * blend_weight;
+#else
+	out_vertex = in_vertex * blend_weight;
+#endif
+#ifdef FINAL_PASS
+	out_vertex = normalize(out_vertex);
+#endif
+#endif // USE_BLEND_SHAPES
+
+#ifdef USE_SKELETON
+
+#define TEX(m) texelFetch(skeleton_texture, ivec2(m % 256u, m / 256u), 0)
+#define GET_BONE_MATRIX(a, b, w) mat2x4(TEX(a), TEX(b)) * w
+
+	uvec4 bones = in_bone_attrib * uvec4(2u);
+	uvec4 bones_a = bones + uvec4(1u);
+
+	highp mat2x4 m = GET_BONE_MATRIX(bones.x, bones_a.x, in_weight_attrib.x);
+	m += GET_BONE_MATRIX(bones.y, bones_a.y, in_weight_attrib.y);
+	m += GET_BONE_MATRIX(bones.z, bones_a.z, in_weight_attrib.z);
+	m += GET_BONE_MATRIX(bones.w, bones_a.w, in_weight_attrib.w);
+
+	mat4 bone_matrix = mat4(m[0], m[1], vec4(0.0, 0.0, 1.0, 0.0), vec4(0.0, 0.0, 0.0, 1.0));
+
+	//reverse order because its transposed
+	out_vertex = (vec4(out_vertex, 0.0, 1.0) * bone_matrix).xy;
+#endif // USE_SKELETON
+
+#else // MODE_2D
+
+#ifdef USE_BLEND_SHAPES
+#ifdef MODE_BLEND_PASS
+	out_vertex = in_vertex + blend_vertex * blend_weight;
+
+#ifdef USE_NORMAL
+	vec3 normal = vec2_to_vec4(in_normal).xyz * blend_shape_count;
+	vec3 normal_blend = oct_to_vec3(blend_normal) * blend_weight;
+#ifdef FINAL_PASS
+	out_normal = vec3_to_oct(normalize(normal + normal_blend));
+#else
+	out_normal = vec4_to_vec2(vec4(normal + normal_blend, 0.0) / blend_shape_count);
+#endif
+#endif // USE_NORMAL
+
+#ifdef USE_TANGENT
+	vec4 tangent = vec2_to_vec4(in_tangent) * blend_shape_count;
+	vec4 tangent_blend = oct_to_tang(blend_tangent) * blend_weight;
+#ifdef FINAL_PASS
+	out_tangent = tang_to_oct(vec4(normalize(tangent.xyz + tangent_blend.xyz), tangent.w));
+#else
+	out_tangent = vec4_to_vec2(vec4((tangent.xyz + tangent_blend.xyz) / blend_shape_count, tangent.w));
+#endif
+#endif // USE_TANGENT
+
+#else // MODE_BLEND_PASS
+	out_vertex = in_vertex * blend_weight;
+
+#ifdef USE_NORMAL
+	vec3 normal = oct_to_vec3(in_normal);
+	out_normal = vec4_to_vec2(vec4(normal * blend_weight / blend_shape_count, 0.0));
+#endif
+#ifdef USE_TANGENT
+	vec4 tangent = oct_to_tang(in_tangent);
+	out_tangent = vec4_to_vec2(vec4(tangent.rgb * blend_weight / blend_shape_count, tangent.w));
+#endif
+#endif // MODE_BLEND_PASS
+#else // USE_BLEND_SHAPES
+
+	// Make attributes available to the skeleton shader if not written by blend shapes.
+	out_vertex = in_vertex;
+#ifdef USE_NORMAL
+	out_normal = in_normal;
+#endif
+#ifdef USE_TANGENT
+	out_tangent = in_tangent;
+#endif
+#endif // USE_BLEND_SHAPES
+
+#ifdef USE_SKELETON
+
+#define TEX(m) texelFetch(skeleton_texture, ivec2(m % 256u, m / 256u), 0)
+#define GET_BONE_MATRIX(a, b, c, w) mat4(TEX(a), TEX(b), TEX(c), vec4(0.0, 0.0, 0.0, 1.0)) * w
+
+	uvec4 bones = in_bone_attrib * uvec4(3);
+	uvec4 bones_a = bones + uvec4(1);
+	uvec4 bones_b = bones + uvec4(2);
+
+	highp mat4 m;
+	m = GET_BONE_MATRIX(bones.x, bones_a.x, bones_b.x, in_weight_attrib.x);
+	m += GET_BONE_MATRIX(bones.y, bones_a.y, bones_b.y, in_weight_attrib.y);
+	m += GET_BONE_MATRIX(bones.z, bones_a.z, bones_b.z, in_weight_attrib.z);
+	m += GET_BONE_MATRIX(bones.w, bones_a.w, bones_b.w, in_weight_attrib.w);
+
+#ifdef USE_EIGHT_WEIGHTS
+	bones = in_bone_attrib2 * uvec4(3);
+	bones_a = bones + uvec4(1);
+	bones_b = bones + uvec4(2);
+
+	m += GET_BONE_MATRIX(bones.x, bones_a.x, bones_b.x, in_weight_attrib2.x);
+	m += GET_BONE_MATRIX(bones.y, bones_a.y, bones_b.y, in_weight_attrib2.y);
+	m += GET_BONE_MATRIX(bones.z, bones_a.z, bones_b.z, in_weight_attrib2.z);
+	m += GET_BONE_MATRIX(bones.w, bones_a.w, bones_b.w, in_weight_attrib2.w);
+#endif
+
+	// Reverse order because its transposed.
+	out_vertex = (vec4(out_vertex, 1.0) * m).xyz;
+#ifdef USE_NORMAL
+	vec3 vertex_normal = oct_to_vec3(out_normal);
+	out_normal = vec3_to_oct(normalize((vec4(vertex_normal, 0.0) * m).xyz));
+#endif // USE_NORMAL
+#ifdef USE_TANGENT
+	vec4 vertex_tangent = oct_to_tang(out_tangent);
+	out_tangent = tang_to_oct(vec4(normalize((vec4(vertex_tangent.xyz, 0.0) * m).xyz), vertex_tangent.w));
+#endif // USE_TANGENT
+#endif // USE_SKELETON
+#endif // MODE_2D
+}
+
+/* clang-format off */
+#[fragment]
+
+void main() {
+
+}
+/* clang-format on */