Allow rectangle textures to be sample with texture() in ESSL3

src/compiler/translator/OutputGLSL.cpp

@@ -94,8 +94,8 @@ ImmutableString TOutputGLSL::translateTextureFunction(const ImmutableString &nam
                                          nullptr};
     static const char *legacyToCoreRename[] = {
         "texture2D", "texture", "texture2DProj", "textureProj", "texture2DLod", "textureLod",
-        "texture2DProjLod", "textureProjLod", "texture2DRect", "texture", "textureCube", "texture",
-        "textureCubeLod", "textureLod",
+        "texture2DProjLod", "textureProjLod", "texture2DRect", "texture", "texture2DRectProj",
+        "textureProj", "textureCube", "texture", "textureCubeLod", "textureLod",
         // Extensions
         "texture2DLodEXT", "textureLod", "texture2DProjLodEXT", "textureProjLod",
         "textureCubeLodEXT", "textureLod", "texture2DGradEXT", "textureGrad",

src/compiler/translator/builtin_function_declarations.txt

@@ -287,6 +287,13 @@ GROUP BEGIN ARB_texture_rectangle
     vec4 texture2DRect(sampler2DRect, vec2);
     vec4 texture2DRectProj(sampler2DRect, vec3);
     vec4 texture2DRectProj(sampler2DRect, vec4);
+  DEFAULT METADATA {"level": "ESSL3_BUILTINS", "op": "CallBuiltInFunction", "extension": "ARB_texture_rectangle"}
+    // We don't have a rectangle texture extension for OpenGL ES however based on the behavior of
+    // rectangle texture in desktop OpenGL, they should be sampled with a "texture" overload in
+    // GLSL version that have such an overload. This is the case for ESSL3 and above.
+    vec4 texture(sampler2DRect, vec2);
+    vec4 textureProj(sampler2DRect, vec3);
+    vec4 textureProj(sampler2DRect, vec4);
 GROUP END ARB_texture_rectangle
 
 // The *Grad* variants are new to both vertex and fragment shaders; the fragment

src/tests/gl_tests/TextureRectangleTest.cpp

@@ -281,8 +281,8 @@ TEST_P(TextureRectangleTest, FramebufferTexture2DLevel)
     ASSERT_GL_ERROR(GL_INVALID_VALUE);
 }
 
-// Test sampling from a rectangle texture
-TEST_P(TextureRectangleTest, SamplingFromRectangle)
+// Test sampling from a rectangle texture using texture2DRect in ESSL1
+TEST_P(TextureRectangleTest, SamplingFromRectangleESSL1)
 {
     ANGLE_SKIP_TEST_IF(!checkExtensionSupported());
 
@@ -321,6 +321,49 @@ TEST_P(TextureRectangleTest, SamplingFromRectangle)
     ASSERT_GL_NO_ERROR();
 }
 
+// Test sampling from a rectangle texture using the texture overload in ESSL3
+TEST_P(TextureRectangleTestES3, SamplingFromRectangleESSL3)
+{
+    ANGLE_SKIP_TEST_IF(!checkExtensionSupported());
+
+    GLTexture tex;
+    glBindTexture(GL_TEXTURE_RECTANGLE_ANGLE, tex);
+    glTexImage2D(GL_TEXTURE_RECTANGLE_ANGLE, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE,
+                 &GLColor::green);
+
+    const std::string vs =
+        "#version 300 es\n"
+        "in vec4 position;\n"
+        "void main()\n"
+        "{\n"
+        "    gl_Position = vec4(position.xy, 0.0, 1.0);\n"
+        "}\n";
+
+    const std::string fs =
+        "#version 300 es\n"
+        "#extension GL_ARB_texture_rectangle : require\n"
+        "precision mediump float;\n"
+        "uniform sampler2DRect tex;\n"
+        "out vec4 fragColor;\n"
+        "void main()\n"
+        "{\n"
+        "    fragColor = texture(tex, vec2(0, 0));\n"
+        "}\n";
+
+    ANGLE_GL_PROGRAM(program, vs, fs);
+    glUseProgram(program);
+
+    GLint location = glGetUniformLocation(program, "tex");
+    ASSERT_NE(-1, location);
+    glUniform1i(location, 0);
+
+    glClearColor(0.0, 0.0, 0.0, 0.0);
+    glClear(GL_COLOR_BUFFER_BIT);
+    drawQuad(program, "position", 0.5f, 1.0f, false);
+    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
+    ASSERT_GL_NO_ERROR();
+}
+
 // Test attaching a rectangle texture and rendering to it.
 TEST_P(TextureRectangleTest, RenderToRectangle)
 {