Add GLES3 infrastructure for lightmap baking in the compatibility backend

2 files changed, 81 insertions, 10 deletions

diff --git a/drivers/gles3/shaders/copy.glsl b/drivers/gles3/shaders/copy.glsl
index f37968a4fd..b5ab15309c 100644
--- a/drivers/gles3/shaders/copy.glsl
+++ b/drivers/gles3/shaders/copy.glsl
@@ -8,6 +8,7 @@ mode_gaussian_blur = #define MODE_GAUSSIAN_BLUR
 mode_mipmap = #define MODE_MIPMAP
 mode_simple_color = #define MODE_SIMPLE_COLOR \n#define USE_COPY_SECTION
 mode_cube_to_octahedral = #define CUBE_TO_OCTAHEDRAL \n#define USE_COPY_SECTION
+mode_cube_to_panorama = #define CUBE_TO_PANORAMA
 
 #[specializations]
 
@@ -53,21 +54,34 @@ uniform highp vec2 pixel_size;
 #endif
 
 #ifdef CUBE_TO_OCTAHEDRAL
-uniform samplerCube source_cube; // texunit:0
-
 vec3 oct_to_vec3(vec2 e) {
 	vec3 v = vec3(e.xy, 1.0 - abs(e.x) - abs(e.y));
 	float t = max(-v.z, 0.0);
 	v.xy += t * -sign(v.xy);
 	return normalize(v);
 }
-#else
-uniform sampler2D source; // texunit:0
+#endif
 
+#ifdef CUBE_TO_PANORAMA
+uniform lowp float mip_level;
 #endif
 
+#if defined(CUBE_TO_OCTAHEDRAL) || defined(CUBE_TO_PANORAMA)
+uniform samplerCube source_cube; // texunit:0
+
+#else // ~(defined(CUBE_TO_OCTAHEDRAL) || defined(CUBE_TO_PANORAMA))
+uniform sampler2D source; // texunit:0
+
+#endif // !(defined(CUBE_TO_OCTAHEDRAL) || defined(CUBE_TO_PANORAMA))
+
 layout(location = 0) out vec4 frag_color;
 
+// This expects 0-1 range input, outside that range it behaves poorly.
+vec3 srgb_to_linear(vec3 color) {
+	// Approximation from http://chilliant.blogspot.com/2012/08/srgb-approximations-for-hlsl.html
+	return color * (color * (color * 0.305306011 + 0.682171111) + 0.012522878);
+}
+
 void main() {
 #ifdef MODE_SIMPLE_COPY
 	vec4 color = texture(source, uv_interp);
@@ -111,4 +125,21 @@ void main() {
 	frag_color = texture(source_cube, dir);
 
 #endif
+
+#ifdef CUBE_TO_PANORAMA
+
+	const float PI = 3.14159265359;
+
+	float phi = uv_interp.x * 2.0 * PI;
+	float theta = uv_interp.y * PI;
+
+	vec3 normal;
+	normal.x = sin(phi) * sin(theta) * -1.0;
+	normal.y = cos(theta);
+	normal.z = cos(phi) * sin(theta) * -1.0;
+
+	vec3 color = srgb_to_linear(textureLod(source_cube, normal, mip_level).rgb);
+	frag_color = vec4(color, 1.0);
+
+#endif
 }
diff --git a/drivers/gles3/shaders/scene.glsl b/drivers/gles3/shaders/scene.glsl
index e95d684763..a92eedd1ec 100644
--- a/drivers/gles3/shaders/scene.glsl
+++ b/drivers/gles3/shaders/scene.glsl
@@ -31,6 +31,7 @@ USE_ADDITIVE_LIGHTING = false
 // these are false, we are doing a directional light pass.
 ADDITIVE_OMNI = false
 ADDITIVE_SPOT = false
+RENDER_MATERIAL = false
 
 
 #[vertex]
@@ -90,7 +91,7 @@ layout(location = 3) in vec4 color_attrib;
 layout(location = 4) in vec2 uv_attrib;
 #endif
 
-#if defined(UV2_USED) || defined(USE_LIGHTMAP)
+#if defined(UV2_USED) || defined(USE_LIGHTMAP) || defined(RENDER_MATERIAL)
 layout(location = 5) in vec2 uv2_attrib;
 #endif
 
@@ -160,12 +161,12 @@ layout(std140) uniform SceneData { // ubo:2
 	mediump vec4 ambient_light_color_energy;
 
 	mediump float ambient_color_sky_mix;
-	bool material_uv2_mode;
+	float pad2;
 	float emissive_exposure_normalization;
 	bool use_ambient_light;
+
 	bool use_ambient_cubemap;
 	bool use_reflection_cubemap;
-
 	float fog_aerial_perspective;
 	float time;
 
@@ -249,6 +250,10 @@ uniform highp vec4 uv_scale;
 
 uniform highp uint model_flags;
 
+#ifdef RENDER_MATERIAL
+uniform mediump vec2 uv_offset;
+#endif
+
 /* Varyings */
 
 out highp vec3 vertex_interp;
@@ -511,6 +516,12 @@ void main() {
 #else
 	gl_Position = projection_matrix * vec4(vertex_interp, 1.0);
 #endif
+
+#ifdef RENDER_MATERIAL
+	gl_Position.xy = (uv2_attrib.xy + uv_offset) * 2.0 - 1.0;
+	gl_Position.z = 0.00001;
+	gl_Position.w = 1.0;
+#endif
 }
 
 /* clang-format off */
@@ -632,12 +643,12 @@ layout(std140) uniform SceneData { // ubo:2
 	mediump vec4 ambient_light_color_energy;
 
 	mediump float ambient_color_sky_mix;
-	bool material_uv2_mode;
+	float pad2;
 	float emissive_exposure_normalization;
 	bool use_ambient_light;
+
 	bool use_ambient_cubemap;
 	bool use_reflection_cubemap;
-
 	float fog_aerial_perspective;
 	float time;
 
@@ -878,8 +889,20 @@ vec2 multiview_uv(vec2 uv) {
 uniform highp mat4 world_transform;
 uniform mediump float opaque_prepass_threshold;
 
+#ifndef MODE_RENDER_DEPTH
+#ifdef RENDER_MATERIAL
+layout(location = 0) out vec4 albedo_output_buffer;
+layout(location = 1) out vec4 normal_output_buffer;
+layout(location = 2) out vec4 orm_output_buffer;
+layout(location = 3) out vec4 emission_output_buffer;
+
+#else // !RENDER_MATERIAL
+// Normal color rendering.
 layout(location = 0) out vec4 frag_color;
 
+#endif // !RENDER_MATERIAL
+#endif // !MODE_RENDER_DEPTH
+
 vec3 F0(float metallic, float specular, vec3 albedo) {
 	float dielectric = 0.16 * specular * specular;
 	// use albedo * metallic as colored specular reflectance at 0 angle for metallic materials;
@@ -1660,6 +1683,23 @@ void main() {
 
 // Nothing happens, so a tree-ssa optimizer will result in no fragment shader :)
 #else // !MODE_RENDER_DEPTH
+
+#ifdef RENDER_MATERIAL
+
+	albedo_output_buffer.rgb = albedo;
+	albedo_output_buffer.a = alpha;
+
+	normal_output_buffer.rgb = normal * 0.5 + 0.5;
+	normal_output_buffer.a = 0.0;
+
+	orm_output_buffer.r = ao;
+	orm_output_buffer.g = roughness;
+	orm_output_buffer.b = metallic;
+	orm_output_buffer.a = 1.0;
+
+	emission_output_buffer.rgb = emission;
+	emission_output_buffer.a = 0.0;
+#else // !RENDER_MATERIAL
 #ifdef BASE_PASS
 #ifdef MODE_UNSHADED
 	frag_color = vec4(albedo, alpha);
@@ -1914,6 +1954,6 @@ void main() {
 
 	frag_color.rgb += additive_light_color;
 #endif // USE_ADDITIVE_LIGHTING
-
+#endif // !RENDER_MATERIAL
 #endif //!MODE_RENDER_DEPTH
 }