Vulkan shader testing

/**
 * Vulkan Engine
 *
 * Copyright (C) 2016-2017 Pawel Kaczynski
 */

#pragma once

#include "VulkanCore.h"

#ifdef __ANDROID__
#include "shaderc/shaderc.hpp"
#else
#include <shaderc/shaderc.hpp>
#endif

/**
 * @file Shaders.h
 */

VULKAN_NS_BEGIN

static const char* VULKAN_TESSELATION_CONTROL_SHADER_TEXT =
    "#version 450\n"
    "layout (vertices = 3) out;\n"
    "layout (location = 0) in vec4 inColor[];\n"
    "layout (location = 3) in mat4 inProjMatrix[];\n"
    "layout (location = 6) in mat4 inViewMatrix[];\n"
    "layout (location = 9) in vec4 inUndistortion[];\n"
    "layout (location = 0) out vec4 outColor[3];\n"
    "layout (location = 3) out mat4 outProjMatrix[3];\n"
    "layout (location = 6) out mat4 outViewMatrix[3];\n"
    "layout (location = 9) out mat4 outUndistortion[3];\n"
    "void main()\n"
    "{\n"
    "    outColor[gl_InvocationID] = inColor[gl_InvocationID];\n"
    "    outProjMatrix[gl_InvocationID] = inProjMatrix[gl_InvocationID];\n"
    "    outViewMatrix[gl_InvocationID] = inViewMatrix[gl_InvocationID];\n"
    "    outUndistortion[gl_InvocationID] = inUndistortion[gl_InvocationID];\n"
    "    if (gl_InvocationID == 0)\n"
    "    {\n"
    "        gl_TessLevelInner[0] = 4.f;\n"
    "        gl_TessLevelOuter[0] = 4.f;\n"
    "        gl_TessLevelOuter[1] = 4.f;\n"
    "        gl_TessLevelOuter[2] = 4.f;\n"
    "    }\n"
    "   gl_out[gl_InvocationID].gl_Position = gl_in[gl_InvocationID].gl_Position;\n"
    "}\n";

static const char* VULKAN_TESSELATION_EVALUATION_SHADER_TEXT =
    "#version 450 core\n"
    "layout (triangles, equal_spacing, cw) in;\n"
    "layout (location = 0) in vec4 inColor[];\n"
    "layout (location = 3) in vec4 inProjMatrix[];\n"
    "layout (location = 6) in mat4 inViewMatrix[];\n"
    "layout (location = 9) in vec4 inUndistortion[];\n"
    "layout (location = 0) out vec4 outColor;\n"
    "vec4 undistort(vec4 pos) {\n"
    "    float maxRadiusSquared = 100.0;\n"
    "    pos = myUniformValues.modelViewMatrix * pos;\n"
    "    float r2 = clamp(dot(pos.xy, pos.xy) / (pos.z * pos.z), 0, maxRadiusSquared);\n"
    "    pos.xy *= 1 + (myUniformValues.undistortion.x + myUniformValues.undistortion.y * r2) * r2;\n"
    "    return pos;\n"
    "}\n"
    "void main()\n"
    "{\n"
    "   outColor = inColor[0];\n"
    "   gl_Position = gl_in[0].gl_Position * gl_TessCoord.x +\n"
    "               gl_in[1].gl_Position * gl_TessCoord.y +\n"
    "               gl_in[2].gl_Position * gl_TessCoord.z;\n"
    "   gl_Position = inProjMatrix[0] * inViewMatrix[0] * gl_Position;\n"
    "}\n";

static const char* VULKAN_VERTEX_SHADER_TEXT =
    "#version 400\n"
    "#extension GL_ARB_separate_shader_objects : enable\n"
    "#extension GL_ARB_shading_language_420pack : enable\n"
    "layout (std140, binding = 0) uniform uniformValues {\n"
    "    mat4 modelViewMatrix;\n"
    "    mat4 projectionMatrix;\n"
    "    vec4 undistortion;\n"
    "} myUniformValues;\n"
    "layout (location = 0) in vec4 pos;\n"
    "layout (location = 1) in vec4 inColor;\n"
    "layout (location = 0) out vec4 outColor;\n"
    "layout (location = 1) out mat4 outProjMatrix;\n"
    "layout (location = 5) out mat4 outViewMatrix;\n"
    "layout (location = 9) out mat4 outUndistortion;\n"
    "vec4 undistort(vec4 pos) {\n"
    "    float maxRadiusSquared = 100.0;\n"
    "    pos = myUniformValues.modelViewMatrix * pos;\n"
    "    float r2 = clamp(dot(pos.xy, pos.xy) / (pos.z * pos.z), 0, maxRadiusSquared);\n"
    "    pos.xy *= 1 + (myUniformValues.undistortion.x + myUniformValues.undistortion.y * r2) * r2;\n"
    "    return pos;\n"
    "}\n"
    "void main() {\n"
    "   outColor = inColor;\n"
    "   outProjMatrix = myUniformValues.projectionMatrix;\n"
    "   outViewMatrix = myUniformValues.modelViewMatrix;\n"
    "   outUndistortion = myUniformValues.undistortion;\n"
    "//   gl_Position = myUniformValues.projectionMatrix * undistort(pos);\n"
    "   gl_Position = pos;\n"
    "}\n";

static const char* VULKAN_FRAGMENT_SHADER_TEXT =
    "#version 400\n"
    "#extension GL_ARB_separate_shader_objects : enable\n"
    "#extension GL_ARB_shading_language_420pack : enable\n"
    "layout (location = 0) in vec4 inColor;\n"
    "layout (location = 0) out vec4 outColor;\n"
    "void main() {\n"
    "   outColor = inColor;\n"
    "}\n";

struct ShaderEntry
{
    std::vector<const char*> vertexShaders;
    std::vector<const char*> fragmentShaders;
    std::vector<const char*> tesselationControlShaders;
    std::vector<const char*> tesselationEvaluationShaders;
};

// #REFACTOR
#ifdef __ANDROID__
struct shader_type_mapping {
    VkShaderStageFlagBits vkshader_type;
    shaderc_shader_kind shaderc_type;
};
static const shader_type_mapping shader_map_table[] = {
    {VK_SHADER_STAGE_VERTEX_BIT, shaderc_glsl_vertex_shader},
    {VK_SHADER_STAGE_TESSELLATION_CONTROL_BIT, shaderc_glsl_tess_control_shader},
    {VK_SHADER_STAGE_TESSELLATION_EVALUATION_BIT, shaderc_glsl_tess_evaluation_shader},
    {VK_SHADER_STAGE_GEOMETRY_BIT, shaderc_glsl_geometry_shader},
    {VK_SHADER_STAGE_FRAGMENT_BIT, shaderc_glsl_fragment_shader},
    {VK_SHADER_STAGE_COMPUTE_BIT, shaderc_glsl_compute_shader},
};
#endif

VULKAN_NS_END