static GLboolean renderToPixelBuffer(GLubyte* pixels, const GLint width, const GLint height)
{
GLint x, y, index;
GLfloat pixelColor[4];
// Generate the ray directions depending on FOV, width and height.
if (!glusRaytracePerspectivef(g_directionBuffer, 0, 30.0f, width, height))
{
printf("Error: Could not create direction buffer.\n");
return GLUS_FALSE;
}
// Rendering only once, so direction buffer can be overwritten.
glusRaytraceLookAtf(g_positionBuffer, g_directionBuffer, g_directionBuffer, 0, width, height, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f);
// Ray tracing over all pixels
for (y = 0; y < HEIGHT; y++)
{
for (x = 0; x < WIDTH; x++)
{
index = (x + y * WIDTH);
trace(pixelColor, &g_positionBuffer[index * 4], &g_directionBuffer[index * 3], 0);
// Resolve to pixel buffer, which is used for the texture.
pixels[index * BYTES_PER_PIXEL + 0] = (GLubyte)(glusMinf(1.0f, pixelColor[0]) * 255.0f);
pixels[index * BYTES_PER_PIXEL + 1] = (GLubyte)(glusMinf(1.0f, pixelColor[1]) * 255.0f);
pixels[index * BYTES_PER_PIXEL + 2] = (GLubyte)(glusMinf(1.0f, pixelColor[2]) * 255.0f);
}
}
return GLUS_TRUE;
}
GLUSboolean init(GLUSvoid)
{
GLfloat textureToWorldNormalMatrix[16];
// The maximum detail level which is 2^s = sMapExtend.
GLuint sMaxDetailLevel;
// The maximum detail level which is 2^t = tMapExtend.
GLuint tMaxDetailLevel;
// The overall maximum detail level from s and t.
GLuint overallMaxDetailLevel;
// Step for s and t direction.
GLfloat detailStep;
GLuint s, t;
GLUStgaimage image;
GLfloat* map = 0;
GLuint* indices = 0;
GLUStextfile vertexSource;
GLUStextfile controlSource;
GLUStextfile evaluationSource;
GLUStextfile geometrySource;
GLUStextfile fragmentSource;
GLfloat lightDirection[3] = { 1.0f, 1.0f, 1.0f };
glusVector3Normalizef(lightDirection);
g_topView.cameraPosition[0] = 0.0f;
g_topView.cameraPosition[1] = 30000.0f * METERS_TO_VIRTUAL_WORLD_SCALE;
g_topView.cameraPosition[2] = 0.0f;
g_topView.cameraPosition[3] = 1.0;
g_topView.cameraDirection[0] = 0.0f;
g_topView.cameraDirection[1] = -1.0f;
g_topView.cameraDirection[2] = 0.0f;
g_topView.cameraUp[0] = 0.0f;
g_topView.cameraUp[1] = 0.0f;
g_topView.cameraUp[2] = -1.0f;
g_topView.fov = 40.0f;
g_personView.cameraPosition[0] = 0.0f;
g_personView.cameraPosition[1] = 4700.0f * METERS_TO_VIRTUAL_WORLD_SCALE;
g_personView.cameraPosition[2] = 0.0f;
g_personView.cameraPosition[3] = 1.0;
g_personView.cameraDirection[0] = 0.0f;
g_personView.cameraDirection[1] = 0.0f;
g_personView.cameraDirection[2] = -1.0f;
g_personView.cameraUp[0] = 0.0f;
g_personView.cameraUp[1] = 1.0f;
g_personView.cameraUp[2] = 0.0f;
g_personView.fov = 60.0f;
g_activeView = &g_personView;
if (!glusLoadTgaImage(NORMAL_MAP, &image))
{
printf("Could not load normal picture '%s'!\n", NORMAL_MAP);
return GLUS_FALSE;
}
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glGenTextures(1, &g_normalMapTexture);
glBindTexture(GL_TEXTURE_RECTANGLE, g_normalMapTexture);
glTexImage2D(GL_TEXTURE_RECTANGLE, 0, image.format, image.width, image.height, 0, image.format, GL_UNSIGNED_BYTE, image.data);
glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glusDestroyTgaImage(&image);
if (!glusLoadTgaImage(HEIGHT_MAP, &image))
{
printf("Could not load height picture '%s'!\n", HEIGHT_MAP);
return GLUS_FALSE;
}
glGenTextures(1, &g_heightMapTexture);
glBindTexture(GL_TEXTURE_RECTANGLE, g_heightMapTexture);
glTexImage2D(GL_TEXTURE_RECTANGLE, 0, image.format, image.width, image.height, 0, image.format, GL_UNSIGNED_BYTE, image.data);
glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
g_sMapExtend = (GLfloat) image.width;
g_tMapExtend = (GLfloat) image.height;
glusDestroyTgaImage(&image);
// Calculate the detail level for the s and ...
sMaxDetailLevel = (GLuint) floorf(logf(g_sMapExtend) / logf(2.0f));
// ... t extend
tMaxDetailLevel = (GLuint) floorf(logf(g_tMapExtend) / logf(2.0f));
overallMaxDetailLevel = glusMinf(sMaxDetailLevel, tMaxDetailLevel);
// Do checking of calculated parameters
if (MINIMUM_DETAIL_LEVEL > overallMaxDetailLevel)
{
printf("Detail level to high %d > %d\n", MINIMUM_DETAIL_LEVEL, overallMaxDetailLevel);
return GLUS_FALSE;
}
if (MINIMUM_DETAIL_LEVEL + DETAIL_LEVEL_FIRST_PASS > overallMaxDetailLevel)
{
printf("First pass detail level to high %d > %d\n", MINIMUM_DETAIL_LEVEL + DETAIL_LEVEL_FIRST_PASS, overallMaxDetailLevel);
return GLUS_FALSE;
}
if (powf(2.0f, overallMaxDetailLevel - (MINIMUM_DETAIL_LEVEL + DETAIL_LEVEL_FIRST_PASS)) > 32.0f)
{
printf("Tessellation level to high %d > 32\n", (GLint) powf(2.0f, overallMaxDetailLevel - (MINIMUM_DETAIL_LEVEL + DETAIL_LEVEL_FIRST_PASS)));
return GLUS_FALSE;
}
detailStep = powf(2.0f, overallMaxDetailLevel - MINIMUM_DETAIL_LEVEL);
g_sNumPoints = (GLuint) ceilf(g_sMapExtend / detailStep) - 1;
g_tNumPoints = (GLuint) ceilf(g_tMapExtend / detailStep) - 1;
//
// Generate the flat terrain mesh.
//
map = (GLUSfloat*) malloc(g_sNumPoints * g_tNumPoints * 2 * sizeof(GLfloat));
indices = (GLuint*) malloc(g_sNumPoints * g_tNumPoints * sizeof(GLuint));
for (t = 0; t < g_tNumPoints; t++)
{
for (s = 0; s < g_sNumPoints; s++)
{
map[t * g_sNumPoints * 2 + s * 2 + 0] = 0.5f + detailStep / 2.0f + (GLfloat) s * detailStep;
map[t * g_sNumPoints * 2 + s * 2 + 1] = 0.5f + detailStep / 2.0f + (GLfloat) t * detailStep;
indices[t * g_sNumPoints + s + 0] = (t + 0) * g_sNumPoints + s + 0;
}
}
//
// Transferring vertices and indices into GPU
//
// Pass one
glGenBuffers(1, &g_verticesPassOneVBO);
glBindBuffer(GL_ARRAY_BUFFER, g_verticesPassOneVBO);
glBufferData(GL_ARRAY_BUFFER, g_sNumPoints * g_tNumPoints * 2 * sizeof(GLfloat), map, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glGenBuffers(1, &g_indicesPassOneVBO);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_indicesPassOneVBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, g_sNumPoints * g_tNumPoints * sizeof(GLuint), indices, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
// Pass two.
glGenBuffers(1, &g_verticesPassTwoVBO);
glBindBuffer(GL_ARRAY_BUFFER, g_verticesPassTwoVBO);
// Calculate enough space!
glBufferData(GL_ARRAY_BUFFER, g_sNumPoints * g_tNumPoints * (GLuint) pow(4, DETAIL_LEVEL_FIRST_PASS + 1) * 2 * sizeof(GLfloat), 0, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
//
free(map);
map = 0;
free(indices);
indices = 0;
//
if (!glusLoadTgaImage(COLOR_MAP, &image))
{
printf("Could not load color picture '%s'!\n", COLOR_MAP);
return GLUS_FALSE;
}
glGenTextures(1, &g_colorMapTexture);
glBindTexture(GL_TEXTURE_2D, g_colorMapTexture);
glTexImage2D(GL_TEXTURE_2D, 0, image.format, image.width, image.height, 0, image.format, GL_UNSIGNED_BYTE, image.data);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glusDestroyTgaImage(&image);
//
glGenQueries(1, &g_transformFeedbackQuery);
//
// Creating the shader program.
//
// Pass one.
glusLoadTextFile("../Example14/shader/PassOne.vert.glsl", &vertexSource);
glusLoadTextFile("../Example14/shader/PassOne.geom.glsl", &geometrySource);
glusLoadTextFile("../Example14/shader/PassOne.frag.glsl", &fragmentSource);
// Compile and ...
glusCreateProgramFromSource(&g_programPassOne, (const GLUSchar**) &vertexSource.text, 0, 0, (const GLUSchar**) &geometrySource.text, (const GLUSchar**) &fragmentSource.text);
// ... add the transform variable ...
glTransformFeedbackVaryings(g_programPassOne.program, 1, (const GLchar**) &TRANSFORM_VARYING, GL_SEPARATE_ATTRIBS);
// ... and link the program
if (!glusLinkProgram(&g_programPassOne))
{
printf("Could not build program one\n");
return GLUS_FALSE;
}
// Destroy the text resource
glusDestroyTextFile(&vertexSource);
glusDestroyTextFile(&geometrySource);
glusDestroyTextFile(&fragmentSource);
g_halfDetailStepPassOneLocation = glGetUniformLocation(g_programPassOne.program, "u_halfDetailStep");
g_detailLevelPassOneLocation = glGetUniformLocation(g_programPassOne.program, "u_detailLevel");
g_fovRadiusPassOneLocation = glGetUniformLocation(g_programPassOne.program, "u_fovRadius");
g_positionTextureSpacePassOneLocation = glGetUniformLocation(g_programPassOne.program, "u_positionTextureSpace");
g_leftNormalTextureSpacePassOneLocation = glGetUniformLocation(g_programPassOne.program, "u_leftNormalTextureSpace");
g_rightNormalTextureSpacePassOneLocation = glGetUniformLocation(g_programPassOne.program, "u_rightNormalTextureSpace");
g_backNormalTextureSpacePassOneLocation = glGetUniformLocation(g_programPassOne.program, "u_backNormalTextureSpace");
// Pass two.
glusLoadTextFile("../Example14/shader/PassTwo.vert.glsl", &vertexSource);
glusLoadTextFile("../Example14/shader/PassTwo.cont.glsl", &controlSource);
glusLoadTextFile("../Example14/shader/PassTwo.eval.glsl", &evaluationSource);
glusLoadTextFile("../Example14/shader/PassTwo.geom.glsl", &geometrySource);
glusLoadTextFile("../Example14/shader/PassTwo.frag.glsl", &fragmentSource);
if (!glusBuildProgramFromSource(&g_shaderProgramPassTwo, (const GLUSchar**) &vertexSource.text, (const GLUSchar**) &controlSource.text, (const GLUSchar**) &evaluationSource.text, (const GLUSchar**) &geometrySource.text, (const GLUSchar**) &fragmentSource.text))
{
printf("Could not build program two\n");
return GLUS_FALSE;
}
glusDestroyTextFile(&vertexSource);
glusDestroyTextFile(&controlSource);
glusDestroyTextFile(&evaluationSource);
glusDestroyTextFile(&geometrySource);
glusDestroyTextFile(&fragmentSource);
g_maxTessellationLevelPassTwoLocation = glGetUniformLocation(g_shaderProgramPassTwo.program, "u_maxTessellationLevel");
g_quadrantStepPassTwoLocation = glGetUniformLocation(g_shaderProgramPassTwo.program, "u_quadrantStep");
g_positionTextureSpacePassTwoLocation = glGetUniformLocation(g_shaderProgramPassTwo.program, "u_positionTextureSpace");
g_heightMapTexturePassTwoLocation = glGetUniformLocation(g_shaderProgramPassTwo.program, "u_heightMapTexture");
g_normalMapTexturePassTwoLocation = glGetUniformLocation(g_shaderProgramPassTwo.program, "u_normalMapTexture");
g_tmvpPassTwoLocation = glGetUniformLocation(g_shaderProgramPassTwo.program, "u_tmvpMatrix");
g_lightDirectionPassTwoLocation = glGetUniformLocation(g_shaderProgramPassTwo.program, "u_lightDirection");
g_colorMapTexturePassTwoLocation = glGetUniformLocation(g_shaderProgramPassTwo.program, "u_colorMapTexture");
//
// One time matrix calculations to convert between texture and world space
glusMatrix4x4Identityf(g_textureToWorldMatrix);
glusMatrix4x4Identityf(textureToWorldNormalMatrix);
glusMatrix4x4Scalef(g_textureToWorldMatrix, HORIZONTAL_PIXEL_SPACING * METERS_TO_VIRTUAL_WORLD_SCALE, VERTICAL_PIXEL_RANGE * METERS_TO_VIRTUAL_WORLD_SCALE, HORIZONTAL_PIXEL_SPACING * METERS_TO_VIRTUAL_WORLD_SCALE);
// Skip this scale for the normal matrix
glusMatrix4x4Scalef(g_textureToWorldMatrix, 1.0f, 1.0f, -1.0f);
glusMatrix4x4Scalef(textureToWorldNormalMatrix, 1.0f, 1.0f, -1.0f);
glusMatrix4x4Translatef(g_textureToWorldMatrix, -g_sMapExtend / 2.0f, 0.0f, -g_tMapExtend / 2.0f);
// No need for the translation matrix in the normal matrix
glusMatrix4x4Copyf(g_worldToTextureMatrix, g_textureToWorldMatrix, GLUS_FALSE);
glusMatrix4x4Inversef(g_worldToTextureMatrix);
glusMatrix4x4Copyf(g_worldToTextureNormalMatrix, textureToWorldNormalMatrix, GLUS_FALSE);
glusMatrix4x4Inversef(g_worldToTextureNormalMatrix);
// Pass one
glUseProgram(g_programPassOne.program);
glUniform1f(g_halfDetailStepPassOneLocation, detailStep / 2.0f);
glUniform1ui(g_detailLevelPassOneLocation, DETAIL_LEVEL_FIRST_PASS);
glUniform1f(g_fovRadiusPassOneLocation, FOV_RADIUS / HORIZONTAL_PIXEL_SPACING * METERS_TO_VIRTUAL_WORLD_SCALE);
glGenVertexArrays(1, &g_vaoPassOne);
glBindVertexArray(g_vaoPassOne);
glBindBuffer(GL_ARRAY_BUFFER, g_verticesPassOneVBO);
// First 0 is the location = 0. See shader source
glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, 0);
// Enable location = 0
glEnableVertexAttribArray(0);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_indicesPassOneVBO);
// Pass two
glUseProgram(g_shaderProgramPassTwo.program);
glUniform3fv(g_lightDirectionPassTwoLocation, 1, lightDirection);
glUniform1ui(g_maxTessellationLevelPassTwoLocation, overallMaxDetailLevel - (MINIMUM_DETAIL_LEVEL + DETAIL_LEVEL_FIRST_PASS));
glUniform1i(g_quadrantStepPassTwoLocation, QUADRANT_STEP);
glGenVertexArrays(1, &g_vaoPassTwo);
glBindVertexArray(g_vaoPassTwo);
glBindBuffer(GL_ARRAY_BUFFER, g_verticesPassTwoVBO);
// First 0 is the location = 0. See shader source
glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, 0);
// Enable location = 0
glEnableVertexAttribArray(0);
//
glActiveTexture(GL_TEXTURE0);
glUniform1i(g_heightMapTexturePassTwoLocation, 0);
glBindTexture(GL_TEXTURE_RECTANGLE, g_heightMapTexture);
glActiveTexture(GL_TEXTURE1);
glUniform1i(g_colorMapTexturePassTwoLocation, 1);
glBindTexture(GL_TEXTURE_2D, g_colorMapTexture);
glActiveTexture(GL_TEXTURE2);
glUniform1i(g_normalMapTexturePassTwoLocation, 2);
glBindTexture(GL_TEXTURE_RECTANGLE, g_normalMapTexture);
//
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
glClearDepth(1.0f);
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
glPatchParameteri(GL_PATCH_VERTICES, 4);
return GLUS_TRUE;
}