LunarG's Vulkan Sample Tutorials Is Easy For Learning This New Graphics API

[phoronix]

Phoronix: LunarG's Vulkan Sample Tutorials Is Easy For Learning This New Graphics API

Earlier this month LunarG published up-to-date Vulkan Sample Tutorials for those wanting to learn more about using this high-performance Khronos graphics API...

http://www.phoronix.com/scan.php?page=news_item&px=Vulkan-Sample-Tutorials

[rabcor]

Cube?! But I wanna learn how to draw a triangle!!! >_<

[birdie]

Vulkan/D3D 12 are anything but "easy".

Here's a cube demo:

[code=c]/*
* Vulkan Samples
*
* Copyright (C) 2015-2016 Valve Corporation
* Copyright (C) 2015-2016 LunarG, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

/*
VULKAN_SAMPLE_SHORT_DESCRIPTION
Draw Cube
*/

/* This is part of the draw cube progression */

#include <util_init.hpp>
#include <assert.h>
#include <string.h>
#include <cstdlib>
#include "cube_data.h"

/* For this sample, we'll start with GLSL so the shader function is plain */
/* and then use the glslang GLSLtoSPV utility to convert it to SPIR-V for */
/* the driver. We do this for clarity rather than using pre-compiled */
/* SPIR-V */

static const char *vertShaderText =
"#version 400\n"
"#extension GL_ARB_separate_shader_objects : enable\n"
"#extension GL_ARB_shading_language_420pack : enable\n"
"layout (std140, binding = 0) uniform bufferVals {\n"
" mat4 mvp;\n"
"} myBufferVals;\n"
"layout (location = 0) in vec4 pos;\n"
"layout (location = 1) in vec4 inColor;\n"
"layout (location = 0) out vec4 outColor;\n"
"out gl_PerVertex { \n"
" vec4 gl_Position;\n"
"};\n"
"void main() {\n"
" outColor = inColor;\n"
" gl_Position = myBufferVals.mvp * pos;\n"
"}\n";

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

int sample_main(int argc, char *argv[]) {
VkResult U_ASSERT_ONLY res;
struct sample_info info = {};
char sample_title[] = "Draw Cube";
const bool depthPresent = true;

process_command_line_args(info, argc, argv);
init_global_layer_properties(info);
init_instance_extension_names(info);
init_device_extension_names(info);
init_instance(info, sample_title);
init_enumerate_device(info);
init_window_size(info, 500, 500);
init_connection(info);
init_window(info);
init_swapchain_extension(info);
init_device(info);

init_command_pool(info);
init_command_buffer(info);
execute_begin_command_buffer(info);
init_device_queue(info);
init_swap_chain(info);
init_depth_buffer(info);
init_uniform_buffer(info);
init_descriptor_and_pipeline_layouts(info, false);
init_renderpass(info, depthPresent);
init_shaders(info, vertShaderText, fragShaderText);
init_framebuffers(info, depthPresent);
init_vertex_buffer(info, g_vb_solid_face_colors_Data,
sizeof(g_vb_solid_face_colors_Data),
sizeof(g_vb_solid_face_colors_Data[0]), false);
init_descriptor_pool(info, false);
init_descriptor_set(info, false);
init_pipeline_cache(info);
init_pipeline(info, depthPresent);

/* VULKAN_KEY_START */

VkClearValue clear_values[2];
clear_values[0].color.float32[0] = 0.2f;
clear_values[0].color.float32[1] = 0.2f;
clear_values[0].color.float32[2] = 0.2f;
clear_values[0].color.float32[3] = 0.2f;
clear_values[1].depthStencil.depth = 1.0f;
clear_values[1].depthStencil.stencil = 0;

VkSemaphore imageAcquiredSemaphore;
VkSemaphoreCreateInfo imageAcquiredSemaphoreCreateInfo;
imageAcquiredSemaphoreCreateInfo.sType =
VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
imageAcquiredSemaphoreCreateInfo.pNext = NULL;
imageAcquiredSemaphoreCreateInfo.flags = 0;

res = vkCreateSemaphore(info.device, &imageAcquiredSemaphoreCreateInfo,
NULL, &imageAcquiredSemaphore);
assert(res == VK_SUCCESS);

// Get the index of the next available swapchain image:
res = vkAcquireNextImageKHR(info.device, info.swap_chain, UINT64_MAX,
imageAcquiredSemaphore, VK_NULL_HANDLE,
&info.current_buffer);
// TODO: Deal with the VK_SUBOPTIMAL_KHR and VK_ERROR_OUT_OF_DATE_KHR
// return codes
assert(res == VK_SUCCESS);

set_image_layout(info, info.buffers[info.current_buffer].image,
VK_IMAGE_ASPECT_COLOR_BIT, VK_IMAGE_LAYOUT_UNDEFINED,
VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);

VkRenderPassBeginInfo rp_begin;
rp_begin.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
rp_begin.pNext = NULL;
rp_begin.renderPass = info.render_pass;
rp_begin.framebuffer = info.framebuffers[info.current_buffer];
rp_begin.renderArea.offset.x = 0;
rp_begin.renderArea.offset.y = 0;
rp_begin.renderArea.extent.width = info.width;
rp_begin.renderArea.extent.height = info.height;
rp_begin.clearValueCount = 2;
rp_begin.pClearValues = clear_values;

vkCmdBeginRenderPass(info.cmd, &rp_begin, VK_SUBPASS_CONTENTS_INLINE);

vkCmdBindPipeline(info.cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, info.pipeline);
vkCmdBindDescriptorSets(info.cmd, VK_PIPELINE_BIND_POINT_GRAPHICS,
info.pipeline_layout, 0, NUM_DESCRIPTOR_SETS,
info.desc_set.data(), 0, NULL);

const VkDeviceSize offsets[1] = {0};
vkCmdBindVertexBuffers(info.cmd, 0, 1, &info.vertex_buffer.buf, offsets);

init_viewports(info);
init_scissors(info);

vkCmdDraw(info.cmd, 12 * 3, 1, 0, 0);
vkCmdEndRenderPass(info.cmd);
res = vkEndCommandBuffer(info.cmd);
const VkCommandBuffer cmd_bufs[] = {info.cmd};
VkFenceCreateInfo fenceInfo;
VkFence drawFence;
fenceInfo.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
fenceInfo.pNext = NULL;
fenceInfo.flags = 0;
vkCreateFence(info.device, &fenceInfo, NULL, &drawFence);

VkPipelineStageFlags pipe_stage_flags =
VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
VkSubmitInfo submit_info[1] = {};
submit_info[0].pNext = NULL;
submit_info[0].sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
submit_info[0].waitSemaphoreCount = 1;
submit_info[0].pWaitSemaphores = &imageAcquiredSemaphore;
submit_info[0].pWaitDstStageMask = &pipe_stage_flags;
submit_info[0].commandBufferCount = 1;
submit_info[0].pCommandBuffers = cmd_bufs;
submit_info[0].signalSemaphoreCount = 0;
submit_info[0].pSignalSemaphores = NULL;

/* Queue the command buffer for execution */
res = vkQueueSubmit(info.graphics_queue, 1, submit_info, drawFence);
assert(res == VK_SUCCESS);

/* Now present the image in the window */

VkPresentInfoKHR present;
present.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
present.pNext = NULL;
present.swapchainCount = 1;
present.pSwapchains = &info.swap_chain;
present.pImageIndices = &info.current_buffer;
present.pWaitSemaphores = NULL;
present.waitSemaphoreCount = 0;
present.pResults = NULL;

/* Make sure command buffer is finished before presenting */
do {
res =
vkWaitForFences(info.device, 1, &drawFence, VK_TRUE, FENCE_TIMEOUT);
} while (res == VK_TIMEOUT);

assert(res == VK_SUCCESS);
res = vkQueuePresentKHR(info.present_queue, &present);
assert(res == VK_SUCCESS);

wait_seconds(1);
/* VULKAN_KEY_END */
if (info.save_images)
write_ppm(info, "drawcube");

vkDestroySemaphore(info.device, imageAcquiredSemaphore, NULL);
vkDestroyFence(info.device, drawFence, NULL);
destroy_pipeline(info);
destroy_pipeline_cache(info);
destroy_descriptor_pool(info);
destroy_vertex_buffer(info);
destroy_framebuffers(info);
destroy_shaders(info);
destroy_renderpass(info);
destroy_descriptor_and_pipeline_layouts(info);
destroy_uniform_buffer(info);
destroy_depth_buffer(info);
destroy_swap_chain(info);
destroy_command_buffer(info);
destroy_command_pool(info);
destroy_device(info);
destroy_window(info);
destroy_instance(info);
return 0;
}[/code]

[rabcor]

Mountain of code...

Aw that doesn't look so bad. (Although it does look like there's so many things that could go wrong...)