Add multiview to the opengl3 driver

2 files changed, 57 insertions, 4 deletions

diff --git a/drivers/gles3/shaders/scene.glsl b/drivers/gles3/shaders/scene.glsl
index efd6036ba9..2bd93796bd 100644
--- a/drivers/gles3/shaders/scene.glsl
+++ b/drivers/gles3/shaders/scene.glsl
@@ -16,6 +16,7 @@ DISABLE_LIGHT_OMNI = false
 DISABLE_LIGHT_SPOT = false
 DISABLE_FOG = false
 USE_RADIANCE_MAP = true
+USE_MULTIVIEW = false
 
 
 #[vertex]
@@ -153,6 +154,15 @@ layout(std140) uniform SceneData { // ubo:2
 }
 scene_data;
 
+#ifdef USE_MULTIVIEW
+layout(std140) uniform MultiviewData { // ubo:8
+	highp mat4 projection_matrix_view[MAX_VIEWS];
+	highp mat4 inv_projection_matrix_view[MAX_VIEWS];
+	highp vec4 eye_offset[MAX_VIEWS];
+}
+multiview_data;
+#endif
+
 uniform highp mat4 world_transform;
 
 #ifdef USE_LIGHTMAP
@@ -250,8 +260,14 @@ void main() {
 #if defined(OVERRIDE_POSITION)
 	highp vec4 position;
 #endif
-	highp mat4 projection_matrix = scene_data.projection_matrix;
-	highp mat4 inv_projection_matrix = scene_data.inv_projection_matrix;
+
+#ifdef USE_MULTIVIEW
+	mat4 projection_matrix = multiview_data.projection_matrix_view[ViewIndex];
+	mat4 inv_projection_matrix = multiview_data.inv_projection_matrix_view[ViewIndex];
+#else
+	mat4 projection_matrix = scene_data.projection_matrix;
+	mat4 inv_projection_matrix = scene_data.inv_projection_matrix;
+#endif //USE_MULTIVIEW
 
 #ifdef USE_INSTANCING
 	vec4 instance_custom = vec4(unpackHalf2x16(instance_color_custom_data.z), unpackHalf2x16(instance_color_custom_data.w));
@@ -339,7 +355,6 @@ void main() {
 /* clang-format off */
 #[fragment]
 
-
 // Default to SPECULAR_SCHLICK_GGX.
 #if !defined(SPECULAR_DISABLED) && !defined(SPECULAR_SCHLICK_GGX) && !defined(SPECULAR_TOON)
 #define SPECULAR_SCHLICK_GGX
@@ -463,6 +478,15 @@ layout(std140) uniform SceneData { // ubo:2
 }
 scene_data;
 
+#ifdef USE_MULTIVIEW
+layout(std140) uniform MultiviewData { // ubo:8
+	highp mat4 projection_matrix_view[MAX_VIEWS];
+	highp mat4 inv_projection_matrix_view[MAX_VIEWS];
+	highp vec4 eye_offset[MAX_VIEWS];
+}
+multiview_data;
+#endif
+
 /* clang-format off */
 
 #GLOBALS
@@ -530,8 +554,13 @@ uniform highp samplerCubeShadow positional_shadow; // texunit:-4
 
 #endif // !defined(DISABLE_LIGHT_OMNI) && !defined(DISABLE_LIGHT_SPOT)
 
-uniform highp sampler2D screen_texture; // texunit:-5
+#ifdef USE_MULTIVIEW
+uniform highp sampler2DArray depth_buffer; // texunit:-6
+uniform highp sampler2DArray screen_texture; // texunit:-5
+#else
 uniform highp sampler2D depth_buffer; // texunit:-6
+uniform highp sampler2D screen_texture; // texunit:-5
+#endif
 
 uniform highp mat4 world_transform;
 uniform mediump float opaque_prepass_threshold;
@@ -884,7 +913,11 @@ vec4 fog_process(vec3 vertex) {
 void main() {
 	//lay out everything, whatever is unused is optimized away anyway
 	vec3 vertex = vertex_interp;
+#ifdef USE_MULTIVIEW
+	vec3 view = -normalize(vertex_interp - multiview_data.eye_offset[ViewIndex].xyz);
+#else
 	vec3 view = -normalize(vertex_interp);
+#endif
 	vec3 albedo = vec3(1.0);
 	vec3 backlight = vec3(0.0);
 	vec4 transmittance_color = vec4(0.0, 0.0, 0.0, 1.0);
diff --git a/drivers/gles3/shaders/tonemap.glsl b/drivers/gles3/shaders/tonemap.glsl
index a478cf9170..0b769e77f2 100644
--- a/drivers/gles3/shaders/tonemap.glsl
+++ b/drivers/gles3/shaders/tonemap.glsl
@@ -44,7 +44,11 @@ in vec2 uv_interp;
 
 layout(location = 0) out vec4 frag_color;
 
+#ifdef USE_MULTIVIEW
+uniform highp sampler2DArray source; //texunit:0
+#else
 uniform highp sampler2D source; //texunit:0
+#endif
 
 #if defined(USE_GLOW_LEVEL1) || defined(USE_GLOW_LEVEL2) || defined(USE_GLOW_LEVEL3) || defined(USE_GLOW_LEVEL4) || defined(USE_GLOW_LEVEL5) || defined(USE_GLOW_LEVEL6) || defined(USE_GLOW_LEVEL7)
 #define USING_GLOW // only use glow when at least one glow level is selected
@@ -191,10 +195,17 @@ vec3 apply_fxaa(vec3 color, vec2 uv_interp, vec2 pixel_size) {
 	const float FXAA_REDUCE_MUL = (1.0 / 8.0);
 	const float FXAA_SPAN_MAX = 8.0;
 
+#ifdef USE_MULTIVIEW
+	vec3 rgbNW = textureLod(source, vec3(uv_interp + vec2(-1.0, -1.0) * pixel_size, ViewIndex), 0.0).xyz;
+	vec3 rgbNE = textureLod(source, vec3(uv_interp + vec2(1.0, -1.0) * pixel_size, ViewIndex), 0.0).xyz;
+	vec3 rgbSW = textureLod(source, vec3(uv_interp + vec2(-1.0, 1.0) * pixel_size, ViewIndex), 0.0).xyz;
+	vec3 rgbSE = textureLod(source, vec3(uv_interp + vec2(1.0, 1.0) * pixel_size, ViewIndex), 0.0).xyz;
+#else
 	vec3 rgbNW = textureLod(source, uv_interp + vec2(-1.0, -1.0) * pixel_size, 0.0).xyz;
 	vec3 rgbNE = textureLod(source, uv_interp + vec2(1.0, -1.0) * pixel_size, 0.0).xyz;
 	vec3 rgbSW = textureLod(source, uv_interp + vec2(-1.0, 1.0) * pixel_size, 0.0).xyz;
 	vec3 rgbSE = textureLod(source, uv_interp + vec2(1.0, 1.0) * pixel_size, 0.0).xyz;
+#endif
 	vec3 rgbM = color;
 	vec3 luma = vec3(0.299, 0.587, 0.114);
 	float lumaNW = dot(rgbNW, luma);
@@ -219,8 +230,13 @@ vec3 apply_fxaa(vec3 color, vec2 uv_interp, vec2 pixel_size) {
 						  dir * rcpDirMin)) *
 			pixel_size;
 
+#ifdef USE_MULTIVIEW
+	vec3 rgbA = 0.5 * (textureLod(source, vec3(uv_interp + dir * (1.0 / 3.0 - 0.5), ViewIndex), 0.0).xyz + textureLod(source, vec3(uv_interp + dir * (2.0 / 3.0 - 0.5), ViewIndex), 0.0).xyz);
+	vec3 rgbB = rgbA * 0.5 + 0.25 * (textureLod(source, vec3(uv_interp + dir * -0.5, ViewIndex), 0.0).xyz + textureLod(source, vec3(uv_interp + dir * 0.5, ViewIndex), 0.0).xyz);
+#else
 	vec3 rgbA = 0.5 * (textureLod(source, uv_interp + dir * (1.0 / 3.0 - 0.5), 0.0).xyz + textureLod(source, uv_interp + dir * (2.0 / 3.0 - 0.5), 0.0).xyz);
 	vec3 rgbB = rgbA * 0.5 + 0.25 * (textureLod(source, uv_interp + dir * -0.5, 0.0).xyz + textureLod(source, uv_interp + dir * 0.5, 0.0).xyz);
+#endif
 
 	float lumaB = dot(rgbB, luma);
 	if ((lumaB < lumaMin) || (lumaB > lumaMax)) {
@@ -231,7 +247,11 @@ vec3 apply_fxaa(vec3 color, vec2 uv_interp, vec2 pixel_size) {
 }
 
 void main() {
+#ifdef USE_MULTIVIEW
+	vec4 color = textureLod(source, vec3(uv_interp, ViewIndex), 0.0);
+#else
 	vec4 color = textureLod(source, uv_interp, 0.0);
+#endif
 
 #ifdef USE_FXAA
 	color.rgb = apply_fxaa(color.rgb, uv_interp, pixel_size);