ES2 Support?

CMakeLists.txt

@@ -11,10 +11,20 @@ if(GLES_COMPATIBILITY_LAYER_USE_DEFAULT_INCLUDE_PATH)
     target_include_directories(gles-compatibility-layer PUBLIC include)
 endif()
 
+# GL Version
+option(GLES_COMPATIBILITY_LAYER_USE_ES3 "Use OpenGL ES 3" TRUE)
+if(GLES_COMPATIBILITY_LAYER_USE_ES3)
+    target_compile_definitions(gles-compatibility-layer PUBLIC GLES_COMPATIBILITY_LAYER_USE_ES3)
+endif()
+
 # Shaders
 include(cmake/util.cmake)
-embed_resource(gles-compatibility-layer src/shaders/main.vsh)
+set(SHADER_FOLDER "es2")
-embed_resource(gles-compatibility-layer src/shaders/main.fsh)
+if(GLES_COMPATIBILITY_LAYER_USE_ES3)
+    set(SHADER_FOLDER "es3")
+endif()
+embed_resource(gles-compatibility-layer "src/shaders/${SHADER_FOLDER}/main.vsh")
+embed_resource(gles-compatibility-layer "src/shaders/${SHADER_FOLDER}/main.fsh")
 
 # Warnings
 target_compile_options(gles-compatibility-layer PRIVATE -Wall -Wextra -Werror -Wpointer-arith -Wshadow -Wnull-dereference)

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023 TheBrokenRail
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

include/GLES/gl.h

@@ -170,6 +170,7 @@ void glLightModelfv(GLenum pname, const GLfloat *params);
 void glPixelStorei(GLenum pname, GLint param);
 
 // Not Part Of OpenGL ES 1.1
+#ifdef GLES_COMPATIBILITY_LAYER_USE_ES3
 #define GL_SAMPLES_PASSED_ARB 0x8c2f // GL_ANY_SAMPLES_PASSED
 #define GL_QUERY_RESULT_AVAILABLE_ARB 0x8867 // GL_QUERY_RESULT_AVAILABLE
 #define GL_QUERY_RESULT_ARB 0x8866 // GL_QUERY_RESULT
@@ -178,6 +179,7 @@ void glDeleteQueriesARB(GLsizei n, const GLuint *ids);
 void glBeginQueryARB(GLenum target, GLuint id);
 void glEndQueryARB(GLenum target);
 void glGetQueryObjectuivARB(GLuint id, GLenum pname, GLuint *params);
+#endif
 void extra_enable_highlight_mode(float red, float green, float blue, float alpha);
 void extra_disable_highlight_mode();
 

src/draw.c

@@ -115,9 +115,10 @@ static GLuint get_shader() {
 }
 
 // Init
+#ifdef GLES_COMPATIBILITY_LAYER_USE_ES3
 GL_FUNC(glGenVertexArrays, void, (GLsizei n, GLuint *arrays));
 GL_FUNC(glBindVertexArray, void, (GLuint array));
-GL_FUNC(glActiveTexture, void, (GLenum texture));
+#endif
 void init_gles_compatibility_layer() {
     // State
     _init_gles_compatibility_layer_state();
@@ -126,9 +127,11 @@ void init_gles_compatibility_layer() {
     reset_variables();
 
     // Setup VAO
+#ifdef GLES_COMPATIBILITY_LAYER_USE_ES3
     GLuint vao;
     real_glGenVertexArrays()(1, &vao);
     real_glBindVertexArray()(vao);
+#endif
 
     // Load Shader
     GLuint program = get_shader();

src/passthrough.c

@@ -120,6 +120,7 @@ GL_FUNC(glBufferSubData, void, (GLenum target, GLintptr offset, GLsizeiptr size,
 void glBufferSubData(GLenum target, GLintptr offset, GLsizeiptr size, const void *data) {
     real_glBufferSubData()(target, offset, size, data);
 }
+#ifdef GLES_COMPATIBILITY_LAYER_USE_ES3
 GL_FUNC(glGenQueries, void, (GLsizei n, GLuint *ids));
 void glGenQueriesARB(GLsizei n, GLuint *ids) {
     real_glGenQueries()(n, ids);
@@ -140,6 +141,7 @@ GL_FUNC(glGetQueryObjectuiv, void, (GLuint id, GLenum pname, GLuint *params));
 void glGetQueryObjectuivARB(GLuint id, GLenum pname, GLuint *params) {
     real_glGetQueryObjectuiv()(id, pname, params);
 }
+#endif
 GL_FUNC(glPixelStorei, void, (GLenum pname, GLint param));
 void glPixelStorei(GLenum pname, GLint param) {
     real_glPixelStorei()(pname, param);

src/passthrough.h

@@ -8,6 +8,18 @@
 
 #include "log.h"
 
+// Testing
+#ifdef GLES_COMPATIBILITY_LAYER_TESTING
+typedef void (*test_t)();
+extern void add_test(const char *function_name);
+#define ADD_TEST(test) \
+    __attribute__((constructor)) static void add_##test##_test() { \
+        add_test(#test); \
+    }
+#else
+#define ADD_TEST(test)
+#endif
+
 // Load GL Function
 #if defined(_WIN32) && !defined(_WIN32_WCE) && !defined(__SCITECH_SNAP__)
 #define GL_APIENTRY __stdcall
@@ -26,4 +38,5 @@
             } \
         } \
         return func; \
-    }
+    } \
+    ADD_TEST(name)

src/shaders/es2/main.fsh

@@ -0,0 +1,50 @@
+#version 100
+precision highp float;
+// Texture
+uniform bool u_has_texture;
+uniform sampler2D u_texture_unit;
+// Color
+varying vec4 v_color;
+varying vec4 v_texture_pos;
+// Highlight Mode
+uniform bool u_highlight_mode;
+uniform vec4 u_highlight_mode_color;
+// Alpha Test
+uniform bool u_alpha_test;
+// Fog
+uniform bool u_fog;
+uniform vec4 u_fog_color;
+uniform bool u_fog_is_linear;
+uniform float u_fog_start;
+uniform float u_fog_end;
+varying vec4 v_fog_eye_position;
+// Main
+void main(void) {
+    gl_FragColor = v_color;
+    // Texture
+    if (u_has_texture) {
+        vec4 texture_color = texture(u_texture_unit, v_texture_pos.xy);
+        if (u_highlight_mode) {
+            texture_color.rgb = u_highlight_mode_color.rgb;
+            texture_color.a *= u_highlight_mode_color.a;
+            gl_FragColor = texture_color;
+        } else {
+            gl_FragColor *= texture_color;
+        }
+    }
+    // Fog
+    if (u_fog) {
+        float fog_factor;
+        if (u_fog_is_linear) {
+            fog_factor = (u_fog_end - length(v_fog_eye_position)) / (u_fog_end - u_fog_start);
+        } else {
+            fog_factor = exp(-u_fog_start * length(v_fog_eye_position));
+        }
+        fog_factor = clamp(fog_factor, 0.0, 1.0);
+        gl_FragColor.rgb = mix(gl_FragColor, u_fog_color, 1.0 - fog_factor).rgb;
+    }
+    // Alpha Test
+    if (u_alpha_test && gl_FragColor.a <= 0.1) {
+        discard;
+    }
+}

src/shaders/es2/main.vsh

@@ -0,0 +1,48 @@
+#version 100
+precision highp float;
+// Matrices
+uniform mat4 u_projection;
+uniform mat4 u_model_view;
+uniform mat4 u_texture;
+// Texture
+attribute vec3 a_vertex_coords;
+attribute vec2 a_texture_coords;
+varying vec4 v_texture_pos;
+// Color
+attribute vec4 a_color;
+varying vec4 v_color;
+// Normal
+attribute vec3 a_normal;
+uniform float u_normal_rescale_factor;
+// Lighting
+uniform bool u_lighting;
+uniform vec4 u_lighting_ambient;
+uniform bool u_lighting_light_source_0;
+uniform vec3 u_lighting_light_source_0_position;
+uniform vec4 u_lighting_light_source_0_diffuse;
+uniform bool u_lighting_light_source_1;
+uniform vec3 u_lighting_light_source_1_position;
+uniform vec4 u_lighting_light_source_1_diffuse;
+// Fog
+varying vec4 v_fog_eye_position;
+// Main
+void main(void) {
+    v_texture_pos = u_texture * vec4(a_texture_coords.xy, 0.0, 1.0);
+    gl_Position = u_projection * u_model_view * vec4(a_vertex_coords.xyz, 1.0);
+    v_color = a_color;
+    v_fog_eye_position = u_model_view * vec4(a_vertex_coords.xyz, 1.0);
+
+    // Lighting
+    if (u_lighting) {
+        vec4 transformed_normal = u_model_view * vec4(a_normal, 0.0) * u_normal_rescale_factor;
+        vec4 total_light = u_lighting_ambient;
+        if (u_lighting_light_source_0) {
+            total_light += max(0.0, dot(transformed_normal.xyz, u_lighting_light_source_0_position)) * u_lighting_light_source_0_diffuse;
+        }
+        if (u_lighting_light_source_1) {
+            total_light += max(0.0, dot(transformed_normal.xyz, u_lighting_light_source_1_position)) * u_lighting_light_source_1_diffuse;
+        }
+        total_light = clamp(total_light, 0.0, 1.0);
+        v_color *= total_light;
+    }
+}

test/.gitignore

@@ -0,0 +1 @@
+/build

test/CMakeLists.txt

@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.16.0)
+project(gles-compatibility-layer-test)
+
+# Build Library
+set(GLES_COMPATIBILITY_LAYER_USE_SDL FALSE CACHE BOOL "" FORCE)
+add_subdirectory(.. gles-compatibility-layer)
+target_compile_definitions(gles-compatibility-layer PRIVATE GLES_COMPATIBILITY_LAYER_TESTING)
+
+# Build
+add_executable(main src/main.cpp)
+target_link_libraries(main gles-compatibility-layer)

test/src/main.cpp

@@ -0,0 +1,125 @@
+#include <cstdio>
+#include <cstdlib>
+
+#include <string>
+#include <vector>
+#include <fstream>
+
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
+
+#include <GLES/gl.h>
+
+#define INFO(format, ...) \
+    { \
+        fprintf(stderr, "[INFO]: " format "\n", ##__VA_ARGS__); \
+    }
+#define WARN(format, ...) \
+    { \
+        fprintf(stderr, "[WARN]: " format "\n", ##__VA_ARGS__); \
+    }
+#define ERR(format, ...) \
+    { \
+        fprintf(stderr, "[ERR]: (%s:%i): " format "\n", __FILE__, __LINE__, ##__VA_ARGS__); \
+        exit(EXIT_FAILURE); \
+    }
+
+// Tests
+#define MAX_TESTS 255
+static const char *tests[MAX_TESTS] = { 0 };
+extern "C" void add_test(const char *function_name) {
+    static int i = 0;
+    if (i >= MAX_TESTS) {
+        ERR("Too Many Tests!");
+    }
+    tests[i++] = function_name;
+}
+
+// Header Files
+static std::vector<std::string> header_lines;
+static void load_header(std::string filename) {
+    std::ifstream file(filename);
+    if (!file.good()) {
+        ERR("Unable To Load Header: %s", filename.c_str());
+    }
+    std::string line;
+    while (std::getline(file, line)) {
+        header_lines.push_back(line);
+    }
+    file.close();
+}
+static void load_headers() {
+    header_lines.clear();
+#ifdef GLES_COMPATIBILITY_LAYER_USE_ES3
+    load_header("/usr/include/GLES3/gl3.h");
+#else
+    load_header("/usr/include/GLES2/gl2.h");
+#endif
+}
+
+// Run Test
+static void run_test(std::string function_name) {
+    // Log
+    INFO("Checking %s...", function_name.c_str());
+
+    // Search Headers
+    std::string check_str = " " + function_name + " ";
+    bool found = false;
+    for (std::string line : header_lines) {
+        if (line.find(check_str) != std::string::npos) {
+            // Found
+            found = true;
+            break;
+        }
+    }
+    if (!found) {
+        ERR("Unable To Find Function");
+    }
+}
+
+// Handle GLFW Error
+static void glfw_error(__attribute__((unused)) int error, const char *description) {
+    WARN("GLFW Error: %s", description);
+}
+
+int main() {
+    INFO("Starting Test");
+
+    // Init GLFW
+    glfwSetErrorCallback(glfw_error);
+    if (!glfwInit()) {
+        ERR("Unable To Initialize GLFW");
+    }
+
+    // Create OpenGL ES Context
+    glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
+#ifdef GLES_COMPATIBILITY_LAYER_USE_ES3
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+#else
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
+#endif
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
+
+    // Create Window
+    GLFWwindow *glfw_window = glfwCreateWindow(640, 480, "Test Window", NULL, NULL);
+    if (!glfw_window) {
+        ERR("Unable To Create GLFW Window");
+    }
+
+    // Make Window Context Current
+    glfwMakeContextCurrent(glfw_window);
+    
+    // Setup Compatibility Layer
+    init_gles_compatibility_layer();
+
+    // Run Tests
+    load_headers();
+    for (int i = 0; tests[i] != NULL; i++) {
+        run_test(tests[i]);
+    }
+
+    // Exit
+    glfwDestroyWindow(glfw_window);
+    glfwTerminate();
+    INFO("Test Complete");
+}