I have the following matrix;
Vertex axisVertices[] =
{
{ { x_0, y_0, 0.0f, 1.0f }, { 1.0f, 1.0f, 1.0f, 1.0f } }, // origin
{ { x_Max, y_0, 0.0f, 1.0f }, { 0.0f, 1.0f, 0.0f, 1.0f } }, // eixo y
{ { x_0, y_Max, 0.0f, 1.0f }, { 0.0f, 0.0f, 1.0f, 1.0f } } // eixo x
};
#define x_0 0.0f
#define y_0 0.0f
#define x_Max 1.5f
#define y_Max 1.7f
I need to be able to initialize the matrix like this. The only possible way of doing this in C is by defining either an enum, or using #define because initializing like this can't be used with a constant.
The problem is, I need to be able to change the values x_Max and y_Max throughout the code, so #define wont work in this case. How can I accomplish this?
You can pass parameters to #defines to create macros
For example you can do
#define INIT(x_0, y_0, x_Max, y_Max) \
{ { { x_0, y_0, 0.0f, 1.0f }, { 1.0f, 1.0f, 1.0f, 1.0f } }, \
{ { x_Max, y_0, 0.0f, 1.0f }, { 0.0f, 1.0f, 0.0f, 1.0f } }, \
{ { x_0, y_Max, 0.0f, 1.0f }, { 0.0f, 0.0f, 1.0f, 1.0f } } }
Which you can use like this
Vertex axisVertices[] = INIT(0.0f, 0.0f, 1.5f, 1.7f);
Then all occurrences of x_0 will be replaces by 0.0f. Just like passing parameters to functions.
Related
arrayOfPaint[i] = new GradientPaint(0.0F, 0.0F, Color.green, 0.0F, 0.0F, Color.green);
// arrayOfPaint[i] = new GradientPaint(0.0F, 0.0F, Color.red, 0.0F, 0.0F, Color.red);
}
}
}
/* arrayOfPaint[0] = new GradientPaint(0.0F, 0.0F, Color.red, 0.0F, 0.0F, Color.red);
arrayOfPaint[1] = new GradientPaint(0.0F, 0.0F, Color.green, 0.0F, 0.0F, Color.green);
arrayOfPaint[2] = new GradientPaint(0.0F, 0.0F, Color.blue, 0.0F, 0.0F, Color.blue); */
CategoryDataset paramCategoryDatasetCylinder = localDefaultCategoryDatasetCylinder;
JFreeChart localJFreeChartCylinder = ChartFactory.createBarChart3D("", "Section", "Percentage", paramCategoryDatasetCylinder ,PlotOrientation.HORIZONTAL, true, true, false);
CategoryPlot localCategoryPlotCylinder = (CategoryPlot)localJFreeChartCylinder.getPlot();
/* if(compCode.equalsIgnoreCase("0094000") && domainName.equalsIgnoreCase("L and T")){
CategoryAxis yAxis = (CategoryAxis)localCategoryPlotCylinder.getDomainAxis();
yAxis.setCategoryLabelPositions(CategoryLabelPositions.UP_45);
} */
localCategoryPlotCylinder.setBackgroundPaint(Color.white);
localCategoryPlotCylinder.setRangeGridlinesVisible(true);
localCategoryPlotCylinder.setRangeGridlinePaint(Color.BLACK);
localJFreeChartCylinder.setBackgroundPaint(new GradientPaint(0.0F, 0.0F, Color.white, 350.0F, 0.0F, Color.white, true));
I have set GREEN color for both of the bars but I am getting difference in color. I am unable to figure out why it is happpening. Please help in this regard
The problem I'm having is that I'm exporting a scene from Blender and my scene is rotated 90 about the Y axis. It's clearly a matrix issue and I'm having problems visualizing the solution. Blender is configured to export with 'up' = (0, 1, 0) and 'forward' = (0, 0, 1).
I'm using row major matrices as indicated by the following.
mat4x4 cons_mat4x4_perspective(float fovy, float aspect_ratio, float near, float far)
{
mat4x4 result = cons_mat4x4_zero();
float half_tan_fovy = tan(fovy / 2.0f); /* in radians */
result.as_rows[0] = cons_vec4(1.0f / (aspect_ratio * half_tan_fovy), 0.0f, 0.0f, 0.0f);
result.as_rows[1] = cons_vec4(0.0f, 1.0f / half_tan_fovy, 0.0f, 0.0f);
result.as_rows[2] = cons_vec4(0.0f, 0.0f, -(far + near) / (far - near), -1.0f);
result.as_rows[3] = cons_vec4(0.0f, 0.0f, -(2.0f * far * near) / (far - near), 0.0f);
return result;
}
// Vulkan clip matrix
clip = cons_mat4x4_floats(1.0f, 0.0f, 0.0f, 0.0f,
0.0f,-1.0f, 0.0f, 0.0f,
0.0f, 0.0f, 0.5f, 0.0f,
0.0f, 0.0f, 0.5f, 1.0f);
mat4x4 cons_mat4x4_lookat(vec3 eye, vec3 center, vec3 up)
{
mat4x4 result = cons_mat4x4_identity();
vec3 f = normalize(vec3_sub(center, eye));
vec3 s = normalize(cross(f, up));
vec3 u = cross(s, f);
result.as_rows[0] = cons_vec4(s.x, u.x, -f.x, 0.0f);
result.as_rows[1] = cons_vec4(s.y, u.y, -f.y, 0.0f);
result.as_rows[2] = cons_vec4(s.z, u.z, -f.z, 0.0f);
result.as_rows[3] = cons_vec4(-vec3_dot(s, eye),
vec3_dot(u, eye),
vec3_dot(f, eye),
1.0f);
return result;
}
My model matrix is the identity matrix and I'm creating a lookat matrix with the following parameters:
vec3 _camera = cons_vec3(0.0f, 5.0f, 0.0f);
vec3 _at = cons_vec3(0.0f, 0.0f, 0.0f);
cons_mat4x4_lookat(_camera, _at, cons_vec3(0.0f, 1.0f, 0.0f));
I tried to convert the code of the question I asked over here.
But when I try to run it, I run into an exception and it points to the mat4(which is an 2-d array of 4x4 floats) header of this(CGLM, which is use for OpenGL math in C as GLM is C++ only library) library.
The C++ code works fine and runs perfectly but why does it crash in C.
Here is the C snippet of the code where 'CGLM' is used(this is the code that crashes):-
glUseProgram(shaderProgram);
mat4 model =
{
{ 1.0f, 0.0f, 0.0f, 0.0f },
{ 0.0f, 1.0f, 0.0f, 0.0f },
{ 0.0f, 0.0f, 1.0f, 0.0f },
{ 0.0f, 0.0f, 0.0f, 1.0f },
};
mat4 projection;
glm_ortho(0.0f, (GLfloat)(WIDTH), (GLfloat)(HEIGHT), 0.0f, -1.0f, 1.0f, projection);
vect2 scale = { 2.0f, 2.0f };
vect2 position = { 50.0f, 0.0f };
vec4 color = { 1.0f, 1.0f, 1.0f, 0.5f };
GLfloat rotation = 0.0f;
glm_translate(model, (vec3){ position[0], position[1], 0.0f });
glm_translate(model, (vec3){ 0.5f * scale[0], 0.5f * scale[1], 0.0f });
glm_rotate(model, rotation, (vec3){ 0.0f, 0.0f, 1.0f }); // Why is this function crashing?
glm_translate(model, (vec3){ -0.5f * scale[0], -0.5f * scale[1], 0.0f });
glm_scale(model, (vec3){ scale[0] * width, scale[1] * height, 1.0f });
glUniformMatrix4fv(glGetUniformLocation(shaderProgram, "projection"), 1, GL_FALSE, (GLfloat *)projection);
glUniformMatrix4fv(glGetUniformLocation(shaderProgram, "model"), 1, GL_FALSE, (GLfloat *)model);
glUniform4f(glGetUniformLocation(shaderProgram, "spriteColor"), color[0], color[1], color[2], color[3]);
Here is the C++ snippet of the code where GLM is used:-
glUseProgram(shaderProgram);
glm::mat4 model(1.0f);
glm::mat4 projection = glm::ortho(0.0f, static_cast<GLfloat>(WIDTH), static_cast<GLfloat>(HEIGHT), 0.0f, -1.0f, 1.0f);
glm::vec2 scale = glm::vec2(2.0f, 2.0f);
glm::vec2 position = glm::vec2(50.0f, 0.0f);
glm::vec4 color = glm::vec4(1.0f, 1.0f, 1.0f, 0.5f);
GLfloat rotation = 0.0f;
model = glm::translate(model, glm::vec3(position, 0.0f));
model = glm::translate(model, glm::vec3(0.5f * scale.x, 0.5f * scale.y, 0.0f));
model = glm::rotate(model, rotation, glm::vec3(0.0f, 0.0f, 1.0f));
model = glm::translate(model, glm::vec3(-0.5f * scale.x, -0.5f * scale.y, 0.0f));
model = glm::scale(model, glm::vec3(scale * glm::vec2(width, height), 1.0f));
glUniformMatrix4fv(glGetUniformLocation(shaderProgram, "projection"), 1, GL_FALSE, glm::value_ptr(projection));
glUniformMatrix4fv(glGetUniformLocation(shaderProgram, "model"), 1, GL_FALSE, glm::value_ptr(model));
glUniform4f(glGetUniformLocation(shaderProgram, "spriteColor"), color.x, color.y, color.z, color.w);
See CGLM documentation
According to the getting started
Aligment is Required: vec4 and mat4 requires 16 byte aligment because
vec4 and mat4 operations are vectorized by SIMD instructions
(SSE/AVX).
So you need to initialize identity matrix like:
mat4 model;
glm_mat4_identity(model);
....
mat4 projection;
glm_mat4_identity(projection);
glm_ortho(0.0f, (GLfloat)(WIDTH), (GLfloat)(HEIGHT), 0.0f, -1.0f, 1.0f, projection);
I am stuck trying to get this code to work in Visual Studio 2012 using glut. It renders a 10/10 3D grid but it will not respond to my input from the keyboard. I am trying to get the camera to rotate around the origin when i hit the left arrow key.
// This example shows how to create a camera for 3D graphics.
#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif
#include <iostream>
#include <cmath>
#include <math.h>
using namespace std;
int g_winWidth = 1024;
int g_winHeight = 512;
bool keyStatus[256];
float angle = 0.0f; //angle for rotating camera
float beginning_angle = 0.0f;
float cx = 10.0, cy = 10.0, cz = -10.0;
void initialGL()
{
glEnable(GL_DEPTH_TEST);
glClearColor (1.0f, 1.0f, 1.0f, 0.0f);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glMatrixMode (GL_MODELVIEW);
glLoadIdentity();
}
//initialize the keyboard keys
void initialization()
{
for(int i =0; i<256; i++)
keyStatus[i] = false;
}
//function to draw the colored x,y, and z axis
void drawCS()
{
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glScalef(10.0f, 10.0f, 10.0f);
glLineWidth(2.5f);
glBegin(GL_LINES);
//axis x
glColor3f(1.0f, 0.0f, 0.0f);
glVertex3f(0.0f, 0.0f, 0.0f);
glVertex3f(0.3f, 0.0f, 0.0f);
//text x
glVertex3f(0.4f, 0.05f, 0.0f);
glVertex3f(0.5f, -0.05f, 0.0f);
glVertex3f(0.4f, -0.05f, 0.0f);
glVertex3f(0.5f, 0.05f, 0.0f);
//axis y
glColor3f(0.0f, 1.0f, 0.0f);
glVertex3f(0.0f, 0.0f, 0.0f);
glVertex3f(0.0f, 0.3f, 0.0f);
//text y
glVertex3f(0.0f, 0.5f, 0.0f);
glVertex3f(0.0f, 0.4f, 0.0f);
glVertex3f(-0.05f, 0.55f, 0.0f);
glVertex3f(0.0f, 0.5f, 0.0f);
glVertex3f(0.05f, 0.55f, 0.0f);
glVertex3f(0.0f, 0.5f, 0.0f);
//axis z
glColor3f(0.0f, 0.0f, 1.0f);
glVertex3f(0.0f, 0.0f, 0.0f);
glVertex3f(0.0f, 0.0f, 0.3f);
//text z
glVertex3f(-0.025f, 0.025f, 0.4f);
glVertex3f(0.025f, 0.025f, 0.4f);
glVertex3f(0.025f, 0.025f, 0.4f);
glVertex3f(-0.025f, -0.025f, 0.4f);
glVertex3f(-0.025f, -0.025f, 0.4f);
glVertex3f(0.025f, -0.025f, 0.4f);
glEnd();
glLineWidth(1.0f);
glPopMatrix();
}
//function to draw the grid
void drawGrid()
{
int size = 10; // determining the grid size and the numbers of cells
if(size%2 != 0) ++size;
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
//glScalef(30.0f, 30.0f, 30.0f);
glBegin(GL_LINES);
for (int i =0; i<size+1; i++) {
if((float)i == size/2.0f) {
glColor3f(0.0f, 0.0f, 0.0f);
} else {
glColor3f(0.8f, 0.8f, 0.8f);
}
glVertex3f(-size/2.0f, 0.0f, -size/2.0f+i);
glVertex3f(size/2.0f, 0.0f, -size/2.0f+i);
glVertex3f(-size/2.0f+i, 0.0f, -size/2.0f);
glVertex3f(-size/2.0f+i, 0.0f, size/2.0f);
}
glEnd();
glPopMatrix();
}
//function to display everything that is happening in window
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
drawGrid();// call to function to draw the grid
drawCS();//call to function to draw the x,y,z axis
glutSwapBuffers();
}
void reshape(int w, int h)
{
g_winWidth = w;
g_winHeight = h;
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
//this function sets the initial position of the camera in 3D space
/*
Need to find a way to rotate around the origin from left to right
*/
gluLookAt( cx, cy, cz, //camera position
0.0f, 0.0f, 0.0f, //what camera looks at
0.0f, 1.0f, 0.0f); //
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45, g_winWidth/g_winHeight, 0.1, 100);//specifies the view for the scene
glViewport(0, 0, w, h);
//angle += 0.1f;
}
//keyboard function for the exit key
void keyboard(unsigned char key, int x, int y)
{
keyStatus[key] = true;
switch (key) {
case 27:
exit(0);
break;
default:
break;
}
}
//sets the keyboard callback to the current window
void keyboardUp(unsigned char key, int x, int y)
{
keyStatus[key] = false;
}
//function for arrow keys output
void processSpecialKeys(int key, int xx, int yy) {
switch(key) {
case GLUT_KEY_LEFT :
//What the left arrow key does
angle -= 0.01f;
cx = sin(angle);
cz = -cos(angle);
break;
case GLUT_KEY_RIGHT :
//What the right arrow key does
break;
case GLUT_KEY_UP :
//What the up arrow key does
break;
case GLUT_KEY_DOWN :
//What the down arrow key does
break;
}
}
int main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGB);
glutInitWindowSize(g_winWidth, g_winHeight);
glutInitWindowPosition(0, 0);
glutCreateWindow("Camera");
initialGL();
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutIdleFunc(display);
glutKeyboardFunc(keyboard);
glutKeyboardUpFunc(keyboardUp);
glutSpecialFunc(processSpecialKeys);
glEnable(GL_DEPTH_TEST);
initialization();
glutMainLoop();
return 1;//changed from EXIT_SUCCESS
}
I'm trying to pass a GLfloat type array through a function but the new variable only take the 1st value of the array (0.5f in this case), what am i doing wrong?
My Code:
void main()
{
// some code
GLfloat vertices[] = {
// Positions // Colors // Texture Coords
0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // Top Right
0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // Bottom Right
-0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, // Bottom Left
-0.5f, 0.5f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f // Top Left
};
passingArray(vertices);
}
void passingArray(GLfloat anotherVertices[])
{
// this anotherVertices only take 1st value of the vertices array
}