Some fixes for shaders and WebGL2

Add padding to UBO data to be multiple of 16 bytes
Add precision definition for samplers
Replace texture2D (deprecated) with texture in shaders

drivers/gles3/rasterizer_canvas_gles3.h

@@ -42,6 +42,7 @@ public:
 
 		float projection_matrix[16];
 		float time;
+		uint8_t padding[12];
 	};
 
 	RasterizerSceneGLES3 *scene_render;
@@ -102,6 +103,7 @@ public:
 			float light_height;
 			float light_outside_alpha;
 			float shadow_distance_mult;
+			uint8_t padding[4];
 		} ubo_data;
 
 		GLuint ubo;

drivers/gles3/rasterizer_scene_gles3.h

@@ -141,6 +141,7 @@ public:
 			float fog_height_min;
 			float fog_height_max;
 			float fog_height_curve;
+			uint8_t padding[8];
 
 		} ubo_data;
 
@@ -150,6 +151,7 @@ public:
 
 			float transform[16];
 			float ambient_contribution;
+			uint8_t padding[12];
 
 		} env_radiance_data;
 

drivers/gles3/shader_gles3.cpp

@@ -273,6 +273,9 @@ ShaderGLES3::Version *ShaderGLES3::get_current_version() {
 	//vertex precision is high
 	strings.push_back("precision highp float;\n");
 	strings.push_back("precision highp int;\n");
+	strings.push_back("precision highp sampler2D;\n");
+	strings.push_back("precision highp samplerCube;\n");
+	strings.push_back("precision highp sampler2DArray;\n");
 
 #if 0
 	if (cc) {
@@ -371,6 +374,9 @@ ShaderGLES3::Version *ShaderGLES3::get_current_version() {
 	//fragment precision is medium
 	strings.push_back("precision highp float;\n");
 	strings.push_back("precision highp int;\n");
+	strings.push_back("precision highp sampler2D;\n");
+	strings.push_back("precision highp samplerCube;\n");
+	strings.push_back("precision highp sampler2DArray;\n");
 
 #if 0
 	if (cc) {

drivers/gles3/shaders/canvas.glsl

@@ -532,11 +532,11 @@ FRAGMENT_SHADER_CODE
 
 #ifdef USE_RGBA_SHADOWS
 
-#define SHADOW_DEPTH(m_tex,m_uv) dot(texture2D((m_tex),(m_uv)),vec4(1.0 / (256.0 * 256.0 * 256.0),1.0 / (256.0 * 256.0),1.0 / 256.0,1)  )
+#define SHADOW_DEPTH(m_tex,m_uv) dot(texture((m_tex),(m_uv)),vec4(1.0 / (256.0 * 256.0 * 256.0),1.0 / (256.0 * 256.0),1.0 / 256.0,1)  )
 
 #else
 
-#define SHADOW_DEPTH(m_tex,m_uv) (texture2D((m_tex),(m_uv)).r)
+#define SHADOW_DEPTH(m_tex,m_uv) (texture((m_tex),(m_uv)).r)
 
 #endif