Shaders for Android (GLES 2) (#10506)

Shader support for OpenGL ES 2 devices (Android)

Co-authored-by: sfan5 <sfan5@live.de>

build/android/app/build.gradle

@@ -64,10 +64,9 @@ task prepareAssets() {
 	copy {
 		from "${projRoot}/builtin" into "${assetsFolder}/builtin"
 	}
-	/*copy {
-		// ToDo: fix Minetest shaders that currently don't work with OpenGL ES
+	copy {
 		from "${projRoot}/client/shaders" into "${assetsFolder}/client/shaders"
-	}*/
+	}
 	copy {
 		from "../native/deps/Android/Irrlicht/shaders" into "${assetsFolder}/client/shaders/Irrlicht"
 	}

builtin/mainmenu/tab_settings.lua

@@ -154,15 +154,18 @@ local function formspec(tabview, name, tabdata)
 		"box[8,0;3.75,4.5;#999999]"
 
 	local video_driver = core.settings:get("video_driver")
-	local shaders_supported = video_driver == "opengl"
-	local shaders_enabled = false
-	if shaders_supported then
-		shaders_enabled = core.settings:get_bool("enable_shaders")
+	local shaders_enabled = core.settings:get_bool("enable_shaders")
+	if video_driver == "opengl" then
 		tab_string = tab_string ..
 			"checkbox[8.25,0;cb_shaders;" .. fgettext("Shaders") .. ";"
 					.. tostring(shaders_enabled) .. "]"
+	elseif video_driver == "ogles2" then
+		tab_string = tab_string ..
+			"checkbox[8.25,0;cb_shaders;" .. fgettext("Shaders (experimental)") .. ";"
+					.. tostring(shaders_enabled) .. "]"
 	else
 		core.settings:set_bool("enable_shaders", false)
+		shaders_enabled = false
 		tab_string = tab_string ..
 			"label[8.38,0.2;" .. core.colorize("#888888",
 					fgettext("Shaders (unavailable)")) .. "]"

builtin/settingtypes.txt

@@ -658,8 +658,8 @@ texture_path (Texture path) path
 #    The rendering back-end for Irrlicht.
 #    A restart is required after changing this.
 #    Note: On Android, stick with OGLES1 if unsure! App may fail to start otherwise.
-#    On other platforms, OpenGL is recommended, and it’s the only driver with
-#    shader support currently.
+#    On other platforms, OpenGL is recommended.
+#    Shaders are supported by OpenGL (desktop only) and OGLES2 (experimental)
 video_driver (Video driver) enum opengl null,software,burningsvideo,direct3d8,direct3d9,opengl,ogles1,ogles2
 
 #    Radius of cloud area stated in number of 64 node cloud squares.

client/shaders/3d_interlaced_merge/opengl_fragment.glsl

@@ -6,9 +6,11 @@ uniform sampler2D textureFlags;
 #define rightImage normalTexture
 #define maskImage textureFlags
 
+varying mediump vec2 varTexCoord;
+
 void main(void)
 {
-	vec2 uv = gl_TexCoord[0].st;
+	vec2 uv = varTexCoord.st;
 	vec4 left = texture2D(leftImage, uv).rgba;
 	vec4 right = texture2D(rightImage, uv).rgba;
 	vec4 mask = texture2D(maskImage, uv).rgba;

client/shaders/3d_interlaced_merge/opengl_vertex.glsl

@@ -1,6 +1,7 @@
+varying mediump vec2 varTexCoord;
+
 void main(void)
 {
-	gl_TexCoord[0] = gl_MultiTexCoord0;
-	gl_Position = gl_Vertex;
-	gl_FrontColor = gl_BackColor = gl_Color;
+	varTexCoord = inTexCoord0;
+	gl_Position = inVertexPosition;
 }

client/shaders/default_shader/opengl_fragment.glsl

@@ -1,4 +1,6 @@
+varying lowp vec4 varColor;
+
 void main(void)
 {
-	gl_FragColor = gl_Color;
+	gl_FragColor = varColor;
 }

client/shaders/default_shader/opengl_vertex.glsl

@@ -1,9 +1,7 @@
-uniform mat4 mWorldViewProj;
+varying lowp vec4 varColor;
 
 void main(void)
 {
-	gl_TexCoord[0] = gl_MultiTexCoord0;
-	gl_Position = mWorldViewProj * gl_Vertex;
-
-	gl_FrontColor = gl_BackColor = gl_Color;
+	gl_Position = mWorldViewProj * inVertexPosition;
+	varColor = inVertexColor;
 }

client/shaders/minimap_shader/opengl_fragment.glsl

@@ -2,9 +2,12 @@ uniform sampler2D baseTexture;
 uniform sampler2D normalTexture;
 uniform vec3 yawVec;
 
+varying lowp vec4 varColor;
+varying mediump vec2 varTexCoord;
+
 void main (void)
 {
-	vec2 uv = gl_TexCoord[0].st;
+	vec2 uv = varTexCoord.st;
 
 	//texture sampling rate
 	const float step = 1.0 / 256.0;
@@ -27,6 +30,6 @@ void main (void)
 
 	vec3 color = (1.1 * diffuse + 0.05 * height + 0.5 * specular) * base.rgb;
 	vec4 col = vec4(color.rgb, base.a);
-	col *= gl_Color;
+	col *= varColor;
 	gl_FragColor = vec4(col.rgb, base.a);
 }

client/shaders/minimap_shader/opengl_vertex.glsl

@@ -1,9 +1,11 @@
-uniform mat4 mWorldViewProj;
 uniform mat4 mWorld;
 
+varying lowp vec4 varColor;
+varying mediump vec2 varTexCoord;
+
 void main(void)
 {
-	gl_TexCoord[0] = gl_MultiTexCoord0;
-	gl_Position = mWorldViewProj * gl_Vertex;
-	gl_FrontColor = gl_BackColor = gl_Color;
+	varTexCoord = inTexCoord0.st;
+	gl_Position = mWorldViewProj * inVertexPosition;
+	varColor = inVertexColor;
 }

client/shaders/nodes_shader/opengl_fragment.glsl

@@ -15,11 +15,12 @@ varying vec3 vPosition;
 // cameraOffset + worldPosition (for large coordinates the limits of float
 // precision must be considered).
 varying vec3 worldPosition;
-
+varying lowp vec4 varColor;
+varying mediump vec2 varTexCoord;
 varying vec3 eyeVec;
 
 const float fogStart = FOG_START;
-const float fogShadingParameter = 1 / ( 1 - fogStart);
+const float fogShadingParameter = 1.0 / ( 1.0 - fogStart);
 
 #ifdef ENABLE_TONE_MAPPING
 
@@ -56,21 +57,21 @@ vec4 applyToneMapping(vec4 color)
 void main(void)
 {
 	vec3 color;
-	vec2 uv = gl_TexCoord[0].st;
+	vec2 uv = varTexCoord.st;
 
 	vec4 base = texture2D(baseTexture, uv).rgba;
-
 #ifdef USE_DISCARD
 	// If alpha is zero, we can just discard the pixel. This fixes transparency
-	// on GPUs like GC7000L, where GL_ALPHA_TEST is not implemented in mesa.
+	// on GPUs like GC7000L, where GL_ALPHA_TEST is not implemented in mesa,
+	// and also on GLES 2, where GL_ALPHA_TEST is missing entirely.
 	if (base.a == 0.0) {
 		discard;
 	}
 #endif
 
 	color = base.rgb;
 
-	vec4 col = vec4(color.rgb * gl_Color.rgb, 1.0); 
+	vec4 col = vec4(color.rgb * varColor.rgb, 1.0);
 
 #ifdef ENABLE_TONE_MAPPING
 	col = applyToneMapping(col);

client/shaders/nodes_shader/opengl_vertex.glsl

@@ -1,4 +1,3 @@
-uniform mat4 mWorldViewProj;
 uniform mat4 mWorld;
 
 // Color of the light emitted by the sun.
@@ -16,7 +15,8 @@ varying vec3 vPosition;
 // cameraOffset + worldPosition (for large coordinates the limits of float
 // precision must be considered).
 varying vec3 worldPosition;
-
+varying lowp vec4 varColor;
+varying mediump vec2 varTexCoord;
 varying vec3 eyeVec;
 
 // Color of the light emitted by the light sources.
@@ -81,13 +81,13 @@ float snoise(vec3 p)
 
 void main(void)
 {
-	gl_TexCoord[0] = gl_MultiTexCoord0;
+	varTexCoord = inTexCoord0.st;
 
 	float disp_x;
 	float disp_z;
 // OpenGL < 4.3 does not support continued preprocessor lines
 #if (MATERIAL_TYPE == TILE_MATERIAL_WAVING_LEAVES && ENABLE_WAVING_LEAVES) || (MATERIAL_TYPE == TILE_MATERIAL_WAVING_PLANTS && ENABLE_WAVING_PLANTS)
-	vec4 pos2 = mWorld * gl_Vertex;
+	vec4 pos2 = mWorld * inVertexPosition;
 	float tOffset = (pos2.x + pos2.y) * 0.001 + pos2.z * 0.002;
 	disp_x = (smoothTriangleWave(animationTimer * 23.0 + tOffset) +
 		smoothTriangleWave(animationTimer * 11.0 + tOffset)) * 0.4;
@@ -96,43 +96,43 @@ void main(void)
 		smoothTriangleWave(animationTimer * 13.0 + tOffset)) * 0.5;
 #endif
 
-	worldPosition = (mWorld * gl_Vertex).xyz;
+	worldPosition = (mWorld * inVertexPosition).xyz;
 
 // OpenGL < 4.3 does not support continued preprocessor lines
 #if (MATERIAL_TYPE == TILE_MATERIAL_WAVING_LIQUID_TRANSPARENT || MATERIAL_TYPE == TILE_MATERIAL_WAVING_LIQUID_OPAQUE || MATERIAL_TYPE == TILE_MATERIAL_WAVING_LIQUID_BASIC) && ENABLE_WAVING_WATER
 	// Generate waves with Perlin-type noise.
 	// The constants are calibrated such that they roughly
 	// correspond to the old sine waves.
-	vec4 pos = gl_Vertex;
+	vec4 pos = inVertexPosition;
 	vec3 wavePos = worldPosition + cameraOffset;
 	// The waves are slightly compressed along the z-axis to get
 	// wave-fronts along the x-axis.
-	wavePos.x /= WATER_WAVE_LENGTH * 3;
-	wavePos.z /= WATER_WAVE_LENGTH * 2;
-	wavePos.z += animationTimer * WATER_WAVE_SPEED * 10;
-	pos.y += (snoise(wavePos) - 1) * WATER_WAVE_HEIGHT * 5;
+	wavePos.x /= WATER_WAVE_LENGTH * 3.0;
+	wavePos.z /= WATER_WAVE_LENGTH * 2.0;
+	wavePos.z += animationTimer * WATER_WAVE_SPEED * 10.0;
+	pos.y += (snoise(wavePos) - 1.0) * WATER_WAVE_HEIGHT * 5.0;
 	gl_Position = mWorldViewProj * pos;
 #elif MATERIAL_TYPE == TILE_MATERIAL_WAVING_LEAVES && ENABLE_WAVING_LEAVES
-	vec4 pos = gl_Vertex;
+	vec4 pos = inVertexPosition;
 	pos.x += disp_x;
 	pos.y += disp_z * 0.1;
 	pos.z += disp_z;
 	gl_Position = mWorldViewProj * pos;
 #elif MATERIAL_TYPE == TILE_MATERIAL_WAVING_PLANTS && ENABLE_WAVING_PLANTS
-	vec4 pos = gl_Vertex;
-	if (gl_TexCoord[0].y < 0.05) {
+	vec4 pos = inVertexPosition;
+	if (varTexCoord.y < 0.05) {
 		pos.x += disp_x;
 		pos.z += disp_z;
 	}
 	gl_Position = mWorldViewProj * pos;
 #else
-	gl_Position = mWorldViewProj * gl_Vertex;
+	gl_Position = mWorldViewProj * inVertexPosition;
 #endif
 
 
 	vPosition = gl_Position.xyz;
 
-	eyeVec = -(gl_ModelViewMatrix * gl_Vertex).xyz;
+	eyeVec = -(mWorldView * inVertexPosition).xyz;
 
 	// Calculate color.
 	// Red, green and blue components are pre-multiplied with
@@ -141,16 +141,16 @@ void main(void)
 	// The pre-baked colors are halved to prevent overflow.
 	vec4 color;
 	// The alpha gives the ratio of sunlight in the incoming light.
-	float nightRatio = 1 - gl_Color.a;
-	color.rgb = gl_Color.rgb * (gl_Color.a * dayLight.rgb + 
-		nightRatio * artificialLight.rgb) * 2;
-	color.a = 1;
+	float nightRatio = 1.0 - inVertexColor.a;
+	color.rgb = inVertexColor.rgb * (inVertexColor.a * dayLight.rgb + 
+		nightRatio * artificialLight.rgb) * 2.0;
+	color.a = 1.0;
 
 	// Emphase blue a bit in darker places
 	// See C++ implementation in mapblock_mesh.cpp final_color_blend()
-	float brightness = (color.r + color.g + color.b) / 3;
+	float brightness = (color.r + color.g + color.b) / 3.0;
 	color.b += max(0.0, 0.021 - abs(0.2 * brightness - 0.021) +
 		0.07 * brightness);
 
-	gl_FrontColor = gl_BackColor = clamp(color, 0.0, 1.0);
+	varColor = clamp(color, 0.0, 1.0);
 }

client/shaders/object_shader/opengl_fragment.glsl

@@ -8,14 +8,16 @@ uniform vec3 eyePosition;
 varying vec3 vNormal;
 varying vec3 vPosition;
 varying vec3 worldPosition;
+varying lowp vec4 varColor;
+varying mediump vec2 varTexCoord;
 
 varying vec3 eyeVec;
 varying float vIDiff;
 
 const float e = 2.718281828459;
 const float BS = 10.0;
 const float fogStart = FOG_START;
-const float fogShadingParameter = 1 / ( 1 - fogStart);
+const float fogShadingParameter = 1.0 / (1.0 - fogStart);
 
 #ifdef ENABLE_TONE_MAPPING
 
@@ -52,13 +54,14 @@ vec4 applyToneMapping(vec4 color)
 void main(void)
 {
 	vec3 color;
-	vec2 uv = gl_TexCoord[0].st;
+	vec2 uv = varTexCoord.st;
 
 	vec4 base = texture2D(baseTexture, uv).rgba;
 
 #ifdef USE_DISCARD
 	// If alpha is zero, we can just discard the pixel. This fixes transparency
-	// on GPUs like GC7000L, where GL_ALPHA_TEST is not implemented in mesa.
+	// on GPUs like GC7000L, where GL_ALPHA_TEST is not implemented in mesa,
+	// and also on GLES 2, where GL_ALPHA_TEST is missing entirely.
 	if (base.a == 0.0) {
 		discard;
 	}
@@ -68,7 +71,7 @@ void main(void)
 
 	vec4 col = vec4(color.rgb, base.a);
 
-	col.rgb *= gl_Color.rgb;
+	col.rgb *= varColor.rgb;
 
 	col.rgb *= emissiveColor.rgb * vIDiff;
 

client/shaders/object_shader/opengl_vertex.glsl

@@ -1,4 +1,3 @@
-uniform mat4 mWorldViewProj;
 uniform mat4 mWorld;
 
 uniform vec3 eyePosition;
@@ -7,6 +6,8 @@ uniform float animationTimer;
 varying vec3 vNormal;
 varying vec3 vPosition;
 varying vec3 worldPosition;
+varying lowp vec4 varColor;
+varying mediump vec2 varTexCoord;
 
 varying vec3 eyeVec;
 varying float vIDiff;
@@ -18,31 +19,31 @@ float directional_ambient(vec3 normal)
 {
 	vec3 v = normal * normal;
 
-	if (normal.y < 0)
-		return dot(v, vec3(0.670820f, 0.447213f, 0.836660f));
+	if (normal.y < 0.0)
+		return dot(v, vec3(0.670820, 0.447213, 0.836660));
 
-	return dot(v, vec3(0.670820f, 1.000000f, 0.836660f));
+	return dot(v, vec3(0.670820, 1.000000, 0.836660));
 }
 
 void main(void)
 {
-	gl_TexCoord[0] = gl_TextureMatrix[0] * gl_MultiTexCoord0;
-	gl_Position = mWorldViewProj * gl_Vertex;
+	varTexCoord = (mTexture * inTexCoord0).st;
+	gl_Position = mWorldViewProj * inVertexPosition;
 
 	vPosition = gl_Position.xyz;
-	vNormal = gl_Normal;
-	worldPosition = (mWorld * gl_Vertex).xyz;
-	eyeVec = -(gl_ModelViewMatrix * gl_Vertex).xyz;
+	vNormal = inVertexNormal;
+	worldPosition = (mWorld * inVertexPosition).xyz;
+	eyeVec = -(mWorldView * inVertexPosition).xyz;
 
 #if (MATERIAL_TYPE == TILE_MATERIAL_PLAIN) || (MATERIAL_TYPE == TILE_MATERIAL_PLAIN_ALPHA)
 	vIDiff = 1.0;
 #else
 	// This is intentional comparison with zero without any margin.
 	// If normal is not equal to zero exactly, then we assume it's a valid, just not normalized vector
-	vIDiff = length(gl_Normal) == 0.0
+	vIDiff = length(inVertexNormal) == 0.0
 		? 1.0
-		: directional_ambient(normalize(gl_Normal));
+		: directional_ambient(normalize(inVertexNormal));
 #endif
 
-	gl_FrontColor = gl_BackColor = gl_Color;
+	varColor = inVertexColor;
 }

client/shaders/selection_shader/opengl_fragment.glsl

@@ -1,9 +1,12 @@
 uniform sampler2D baseTexture;
 
+varying lowp vec4 varColor;
+varying mediump vec2 varTexCoord;
+
 void main(void)
 {
-	vec2 uv = gl_TexCoord[0].st;
+	vec2 uv = varTexCoord.st;
 	vec4 color = texture2D(baseTexture, uv);
-	color.rgb *= gl_Color.rgb;
+	color.rgb *= varColor.rgb;
 	gl_FragColor = color;
 }