Merge pull request #16 from KhronosGroup/cpp-examples

[WIP] Initial set of C++ backend samples.

.gitignore

@@ -11,5 +11,7 @@
 *.suo
 *.sdf
 *.opensdf
+*.shader
+*.a
 
 !CMakeLists.txt

README.md

@@ -111,6 +111,12 @@ glslangValidator -H -V -o test.spv shaders/comp/basic.comp
 ./spirv-cross --version 310 --es test.spv --output test.comp --force-temporary
 ```
 
+### Using shaders generated from C++ backend
+
+Please see `samples/cpp` where some GLSL shaders are compiled to SPIR-V, decompiled to C++ and run with test data.
+Reading through the samples should explain how to use the C++ interface.
+A simple Makefile is included to build all shaders in the directory.
+
 ## Contributing
 
 Contributions to SPIRV-Cross are welcome. See Testing and Licensing sections for details.

samples/cpp/Makefile

@@ -0,0 +1,28 @@
+SOURCES := $(wildcard *.comp)
+SPIRV := $(SOURCES:.comp=.spv)
+CPP_INTERFACE := $(SOURCES:.comp=.spv.cpp)
+CPP_DRIVER := $(SOURCES:.comp=.cpp)
+EXECUTABLES := $(SOURCES:.comp=.shader)
+OBJECTS := $(CPP_DRIVER:.cpp=.o) $(CPP_INTERFACE:.cpp=.o)
+
+CXXFLAGS += -std=c++11 -I../../include -I.
+LDFLAGS += -pthread -lm
+
+all: $(EXECUTABLES)
+
+%.spv: %.comp
+	glslangValidator -V -o $@ $<
+
+%.spv.cpp: %.spv
+	../../spirv-cross --cpp --output $@ $<
+
+%.o: %.cpp
+	$(CXX) -c -o $@ $< $(CXXFLAGS)
+
+%.shader: %.o %.spv.o
+	$(CXX) -o $@ $^ $(LDFLAGS)
+
+clean:
+	$(RM) -f $(EXECUTABLES) $(SPIRV) $(CPP_INTERFACE) $(OBJECTS)
+
+.PHONY: clean

samples/cpp/atomics.comp

@@ -0,0 +1,29 @@
+#version 310 es
+layout(local_size_x = 64) in;
+
+layout(set = 0, binding = 0, std430) readonly buffer SSBO0
+{
+	float inputs[];
+};
+
+layout(set = 0, binding = 1, std430) writeonly buffer SSBO1
+{
+	float outputs[];
+};
+
+layout(set = 0, binding = 2, std430) buffer SSBO2
+{
+	uint counter;
+};
+
+void main()
+{
+	// Builds a tightly packed list of all values less than 10.0.
+	// The output order is random.
+	float value = inputs[gl_GlobalInvocationID.x];
+	if (value < 10.0)
+	{
+		uint output_index = atomicAdd(counter, 1u);
+		outputs[output_index] = value;
+	}
+}

samples/cpp/atomics.cpp

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2015-2016 ARM Limited
+ *
+ * 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.
+ */
+
+#include "spirv_cross/external_interface.h"
+#include <stdio.h>
+
+#ifndef GLM_SWIZZLE
+#define GLM_SWIZZLE
+#endif
+
+#ifndef GLM_FORCE_RADIANS
+#define GLM_FORCE_RADIANS
+#endif
+
+#include <glm/glm.hpp>
+using namespace glm;
+
+int main()
+{
+	// First, we get the C interface to the shader.
+	// This can be loaded from a dynamic library, or as here,
+	// linked in as a static library.
+	auto *iface = spirv_cross_get_interface();
+
+	// Create an instance of the shader interface.
+	auto *shader = iface->construct();
+
+	// Build some input data for our compute shader.
+#define NUM_WORKGROUPS 4
+	float a[64 * NUM_WORKGROUPS];
+	float b[64 * NUM_WORKGROUPS] = {};
+	uint32_t counter = 0;
+
+	for (int i = 0; i < 64 * NUM_WORKGROUPS; i++)
+	{
+		a[i] = i * 0.46f;
+	}
+
+	void *aptr = a;
+	void *bptr = b;
+	void *cptr = &counter;
+
+	// Bind resources to the shader.
+	// For resources like samplers and buffers, we provide a list of pointers,
+	// since UBOs, SSBOs and samplers can be arrays, and can point to different types,
+	// which is especially true for samplers.
+	spirv_cross_set_resource(shader, 0, 0, &aptr, sizeof(aptr));
+	spirv_cross_set_resource(shader, 0, 1, &bptr, sizeof(bptr));
+	spirv_cross_set_resource(shader, 0, 2, &cptr, sizeof(cptr));
+
+	// We also have to set builtins.
+	// The relevant builtins will depend on the shader,
+	// but for compute, there are few builtins, which are gl_NumWorkGroups and gl_WorkGroupID.
+	// LocalInvocationID and GlobalInvocationID are inferred when executing the invocation.
+	uvec3 num_workgroups(NUM_WORKGROUPS, 1, 1);
+	uvec3 work_group_id(0, 0, 0);
+	spirv_cross_set_builtin(shader, SPIRV_CROSS_BUILTIN_NUM_WORK_GROUPS, &num_workgroups, sizeof(num_workgroups));
+	spirv_cross_set_builtin(shader, SPIRV_CROSS_BUILTIN_WORK_GROUP_ID, &work_group_id, sizeof(work_group_id));
+
+	// Execute 4 work groups.
+	for (unsigned i = 0; i < NUM_WORKGROUPS; i++)
+	{
+		work_group_id.x = i;
+		iface->invoke(shader);
+	}
+
+	// Call destructor.
+	iface->destruct(shader);
+
+	// Verify our output.
+	// TODO: Implement a test framework that asserts results computed.
+	fprintf(stderr, "Counter = %u\n", counter);
+	for (unsigned i = 0; i < counter; i++)
+	{
+		fprintf(stderr, "[%3u] = %.1f\n", i, b[i]);
+	}
+}

samples/cpp/multiply.comp

@@ -0,0 +1,22 @@
+#version 310 es
+layout(local_size_x = 64) in;
+
+layout(set = 0, binding = 0, std430) readonly buffer SSBO0
+{
+	vec4 a[];
+};
+
+layout(set = 0, binding = 1, std430) readonly buffer SSBO1
+{
+	vec4 b[];
+};
+
+layout(set = 0, binding = 2, std430) buffer SSBO2
+{
+	vec4 c[];
+};
+
+void main()
+{
+	c[gl_GlobalInvocationID.x] = a[gl_GlobalInvocationID.x] * b[gl_GlobalInvocationID.x];
+}

samples/cpp/multiply.cpp

@@ -0,0 +1,93 @@
+/*
+ * Copyright 2015-2016 ARM Limited
+ *
+ * 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.
+ */
+
+#include "spirv_cross/external_interface.h"
+#include <stdio.h>
+
+#ifndef GLM_SWIZZLE
+#define GLM_SWIZZLE
+#endif
+
+#ifndef GLM_FORCE_RADIANS
+#define GLM_FORCE_RADIANS
+#endif
+
+#include <glm/glm.hpp>
+using namespace glm;
+
+int main()
+{
+	// First, we get the C interface to the shader.
+	// This can be loaded from a dynamic library, or as here,
+	// linked in as a static library.
+	auto *iface = spirv_cross_get_interface();
+
+	// Create an instance of the shader interface.
+	auto *shader = iface->construct();
+
+	// Build some input data for our compute shader.
+#define NUM_WORKGROUPS 4
+	vec4 a[64 * NUM_WORKGROUPS];
+	vec4 b[64 * NUM_WORKGROUPS];
+	vec4 c[64 * NUM_WORKGROUPS] = {};
+
+	for (int i = 0; i < 64 * NUM_WORKGROUPS; i++)
+	{
+		a[i] = vec4(100 + i, 101 + i, 102 + i, 103 + i);
+		b[i] = vec4(100 - i, 99 - i, 98 - i, 97 - i);
+	}
+
+	void *aptr = a;
+	void *bptr = b;
+	void *cptr = c;
+
+	// Bind resources to the shader.
+	// For resources like samplers and buffers, we provide a list of pointers,
+	// since UBOs, SSBOs and samplers can be arrays, and can point to different types,
+	// which is especially true for samplers.
+	spirv_cross_set_resource(shader, 0, 0, &aptr, sizeof(aptr));
+	spirv_cross_set_resource(shader, 0, 1, &bptr, sizeof(bptr));
+	spirv_cross_set_resource(shader, 0, 2, &cptr, sizeof(cptr));
+
+	// We also have to set builtins.
+	// The relevant builtins will depend on the shader,
+	// but for compute, there are few builtins, which are gl_NumWorkGroups and gl_WorkGroupID.
+	// LocalInvocationID and GlobalInvocationID are inferred when executing the invocation.
+	uvec3 num_workgroups(NUM_WORKGROUPS, 1, 1);
+	uvec3 work_group_id(0, 0, 0);
+	spirv_cross_set_builtin(shader, SPIRV_CROSS_BUILTIN_NUM_WORK_GROUPS, &num_workgroups, sizeof(num_workgroups));
+	spirv_cross_set_builtin(shader, SPIRV_CROSS_BUILTIN_WORK_GROUP_ID, &work_group_id, sizeof(work_group_id));
+
+	// Execute 4 work groups.
+	for (unsigned i = 0; i < NUM_WORKGROUPS; i++)
+	{
+		work_group_id.x = i;
+		iface->invoke(shader);
+	}
+
+	// Call destructor.
+	iface->destruct(shader);
+
+	// Verify our output.
+	// TODO: Implement a test framework that asserts results computed.
+	for (unsigned i = 0; i < 64 * NUM_WORKGROUPS; i++)
+	{
+		fprintf(stderr, "(%.1f, %.1f, %.1f, %.1f) * (%.1f, %.1f, %.1f, %.1f) => (%.1f, %.1f, %.1f, %.1f)\n",
+			a[i].x, a[i].y, a[i].z, a[i].w,
+			b[i].x, b[i].y, b[i].z, b[i].w,
+			c[i].x, c[i].y, c[i].z, c[i].w);
+	}
+}

samples/cpp/shared.comp

@@ -0,0 +1,36 @@
+#version 310 es
+layout(local_size_x = 64) in;
+
+layout(set = 0, binding = 0, std430) readonly buffer SSBO0
+{
+	float inputs[];
+};
+
+layout(set = 0, binding = 1, std430) writeonly buffer SSBO1
+{
+	float outputs[];
+};
+
+shared float tmp[gl_WorkGroupSize.x];
+
+void main()
+{
+	uint local = gl_LocalInvocationIndex;
+	uint work_group = gl_WorkGroupID.x;
+
+	// Does a trivial parallel reduction through shared memory.
+	tmp[local] = inputs[work_group * gl_WorkGroupSize.x * 2u + local] + inputs[work_group * gl_WorkGroupSize.x * 2u + local + gl_WorkGroupSize.x];
+	memoryBarrierShared();
+	barrier();
+
+	for (uint limit = 32u; limit > 1u; limit >>= 1u)
+	{
+		if (local < limit)
+			tmp[local] = tmp[local] + tmp[local + limit];
+		memoryBarrierShared();
+		barrier();
+	}
+
+	if (local == 0u)
+		outputs[work_group] = tmp[0] + tmp[1];
+}

samples/cpp/shared.cpp

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2015-2016 ARM Limited
+ *
+ * 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.
+ */
+
+#include "spirv_cross/external_interface.h"
+#include <stdio.h>
+
+#ifndef GLM_SWIZZLE
+#define GLM_SWIZZLE
+#endif
+
+#ifndef GLM_FORCE_RADIANS
+#define GLM_FORCE_RADIANS
+#endif
+
+#include <glm/glm.hpp>
+using namespace glm;
+
+int main()
+{
+	// First, we get the C interface to the shader.
+	// This can be loaded from a dynamic library, or as here,
+	// linked in as a static library.
+	auto *iface = spirv_cross_get_interface();
+
+	// Create an instance of the shader interface.
+	auto *shader = iface->construct();
+
+	// Build some input data for our compute shader.
+#define NUM_WORKGROUPS 4
+	float a[128 * NUM_WORKGROUPS];
+	float b[NUM_WORKGROUPS] = {};
+
+	for (int i = 0; i < 128 * NUM_WORKGROUPS; i++)
+	{
+		a[i] = float(i);
+	}
+
+	void *aptr = a;
+	void *bptr = b;
+
+	// Bind resources to the shader.
+	// For resources like samplers and buffers, we provide a list of pointers,
+	// since UBOs, SSBOs and samplers can be arrays, and can point to different types,
+	// which is especially true for samplers.
+	spirv_cross_set_resource(shader, 0, 0, &aptr, sizeof(aptr));
+	spirv_cross_set_resource(shader, 0, 1, &bptr, sizeof(bptr));
+
+	// We also have to set builtins.
+	// The relevant builtins will depend on the shader,
+	// but for compute, there are few builtins, which are gl_NumWorkGroups and gl_WorkGroupID.
+	// LocalInvocationID and GlobalInvocationID are inferred when executing the invocation.
+	uvec3 num_workgroups(NUM_WORKGROUPS, 1, 1);
+	uvec3 work_group_id(0, 0, 0);
+	spirv_cross_set_builtin(shader, SPIRV_CROSS_BUILTIN_NUM_WORK_GROUPS, &num_workgroups, sizeof(num_workgroups));
+	spirv_cross_set_builtin(shader, SPIRV_CROSS_BUILTIN_WORK_GROUP_ID, &work_group_id, sizeof(work_group_id));
+
+	// Execute 4 work groups.
+	for (unsigned i = 0; i < NUM_WORKGROUPS; i++)
+	{
+		work_group_id.x = i;
+		iface->invoke(shader);
+	}
+
+	// Call destructor.
+	iface->destruct(shader);
+
+	// Verify our output.
+	// TODO: Implement a test framework that asserts results computed.
+	for (unsigned i = 0; i < NUM_WORKGROUPS; i++)
+	{
+		float expected_sum = 0.0f;
+		for (unsigned j = i * 128; j < (i + 1) * 128; j++)
+			expected_sum += a[j];
+		fprintf(stderr, "Sum in workgroup #%u = %.1f, expected %.1f\n", i, b[i], expected_sum);
+	}
+}