OpenGL Square not Rendering Correctly - opengl

Question

Correct Rendering:
Incorrect Rendering:
The correct rendering is from me using 6 vertices per square. The incorrect rendering is when I try to re-use vertices and get it down to 4 vertices per square.
Here is the code (I call addSquare 6 times in the example):
module src.UltraMesh;
import grape;
import std.conv;
import std.stdio;
import grape.shader;
import std.math;
import std.stdio;
import std.traits;
import std.conv;
import std.algorithm;
import std.array;
import std.range;
class UltraMesh
{
Appender!(float[]) vertices;
Appender!(int[]) indices;
Appender!(ubyte[]) color;
bool wireframe;
ubyte colorR, colorB, colorG, colorA;
GLuint indiceBuffer;
GLuint vertexBuffer;
GLuint colorBuffer;
GLuint vaoID;
int indiceBufferSize = 0;
int vertexBufferSize = 0;
int colorBufferSize = 0;
bool updateBuffers = true;
GLint cameraUniformLocation;
this()
{
if (program is null) {
initializeShader();
}
wireframe = false;
colorR = to!ubyte(255);
colorB = to!ubyte(0);
colorG = to!ubyte(0);
colorA = to!ubyte(255);
vertices = appender!(float[]); //Points
indices = appender!(int[]); //Edges
color = appender!(ubyte[]);
glGenVertexArrays(1, &vaoID); // Create our Vertex Array Object
glBindVertexArray(vaoID); // Bind our Vertex Array Object so we can use it
//Create buffer for indices
glGenBuffers(1, &indiceBuffer);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indiceBuffer);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, int.sizeof*3, null, GL_DYNAMIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
//Create buffer for vertices
glGenBuffers(1, &vertexBuffer);
//Bind the buffer so we can work on it
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
glBufferData(GL_ARRAY_BUFFER, float.sizeof*9, null, GL_DYNAMIC_DRAW);
//Bind to the attribute so we can do stuff to it
glBindAttribLocation(program, 0, cast(char*)"position");
//Get the attribute location?
GLint _location = glGetAttribLocation(program, cast(char*)"position");
//Enable it for drawing
glEnableVertexAttribArray(_location);
//Describe the data of the attribute?
glVertexAttribPointer(_location, 3, GL_FLOAT, GL_FALSE, 0, null);
//Unbind the buffer
glBindBuffer(GL_ARRAY_BUFFER, 0);
//Create buffer for colors
glGenBuffers(1, &colorBuffer);
//Bind the buffer so we can work on it
glBindBuffer(GL_ARRAY_BUFFER, colorBuffer);
glBufferData(GL_ARRAY_BUFFER, byte.sizeof*12, null, GL_DYNAMIC_DRAW);
//Bind to the attribute so we can do stuff to it
glBindAttribLocation(program, 1, cast(char*)"color");
//Get the attribute location?
_location = glGetAttribLocation(program, cast(char*)"color");
//Enable it for drawing
glEnableVertexAttribArray(_location);
//Describe the data of the attribute?
glVertexAttribPointer(_location, 4, GL_UNSIGNED_BYTE, GL_FALSE, 0, null);
//Unbind the buffer
glBindBuffer(GL_ARRAY_BUFFER, 0);
cameraUniformLocation = glGetUniformLocation(program, cast(char*)"pvmMatrix");
glEnableVertexAttribArray(0); // Disable our Vertex Array Object
glBindVertexArray(0); // Disable our Vertex Buffer Object
}
~this() {
glDeleteBuffers(1, &indiceBuffer);
glDeleteBuffers(1, &vertexBuffer);
glDeleteBuffers(1, &colorBuffer);
}
void updateAllBuffers() {
updateIndiceBufferPartial(0, to!int(indices.data.length));
updateVertexBufferPartial(0, to!int(vertices.data.length));
updateColorBufferPartial(0, to!int(color.data.length));
}
void updateColorBuffer() {
updateColorBufferPartial(0, to!int(color.data.length));
}void updateVertexBuffer() {
updateVertexBufferPartial(0, to!int(vertices.data.length));
}void updateIndiceBuffer() {
updateIndiceBufferPartial(0, to!int(indices.data.length));
}
void reserveIndiceBuffer(int length) {
indiceBufferSize = length;
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indiceBuffer);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, int.sizeof*length, null, GL_DYNAMIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}
void updateIndiceBufferPartial(int start, int length) {
if (indiceBufferSize <= start+length) {
indiceBufferSize = to!int(indiceBufferSize * 2 + 3);
if (indiceBufferSize < start+length) {indiceBufferSize=start+length+3;}
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indiceBuffer);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, int.sizeof*indiceBufferSize, null, GL_DYNAMIC_DRAW);
glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, indices.data.length*int.sizeof, indices.data.ptr);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
} else {
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indiceBuffer);
glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, start*int.sizeof, length*int.sizeof, indices.data[start..start+length].ptr);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}
}
void reserveVertexBuffer(int length) {
vertexBufferSize = length;
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
glBufferData(GL_ARRAY_BUFFER, float.sizeof*length, null, GL_DYNAMIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
}
void updateVertexBufferPartial(int start, int length) {
if (vertexBufferSize <= start+length) {
vertexBufferSize = to!int(vertexBufferSize * 2 + 9);
if (vertexBufferSize < start+length) {vertexBufferSize=start+length+9;}
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
glBufferData(GL_ARRAY_BUFFER, float.sizeof*vertexBufferSize, null, GL_DYNAMIC_DRAW);
glBufferSubData(GL_ARRAY_BUFFER, 0, vertices.data.length*float.sizeof, vertices.data.ptr);
glBindBuffer(GL_ARRAY_BUFFER, 0);
} else {
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
glBufferSubData(GL_ARRAY_BUFFER, start*float.sizeof, length*float.sizeof, vertices.data[start..start+length].ptr);
glBindBuffer(GL_ARRAY_BUFFER, 0);
}
}
void reserveColorBuffer(int length) {
colorBufferSize = length;
glBindBuffer(GL_ARRAY_BUFFER, colorBuffer);
glBufferData(GL_ARRAY_BUFFER, byte.sizeof*length, null, GL_DYNAMIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
}
void updateColorBufferPartial(int start, int length) {
if (colorBufferSize <= start+length) {
colorBufferSize = to!int(colorBufferSize * 2 + 12);
if (colorBufferSize < start+length) {colorBufferSize=start+length+12;}
glBindBuffer(GL_ARRAY_BUFFER, colorBuffer);
glBufferData(GL_ARRAY_BUFFER, byte.sizeof*colorBufferSize, null, GL_DYNAMIC_DRAW);
glBufferSubData(GL_ARRAY_BUFFER, 0, color.data.length*byte.sizeof, color.data.ptr);
glBindBuffer(GL_ARRAY_BUFFER, 0);
} else {
glBindBuffer(GL_ARRAY_BUFFER, colorBuffer);
glBufferSubData(GL_ARRAY_BUFFER, start*byte.sizeof, length*byte.sizeof, color.data[start..start+length].ptr);
glBindBuffer(GL_ARRAY_BUFFER, 0);
}
}
VertexGroup addTriangle(double triangleX, double triangleY, double triangleZ, double width) {
if (vertices.capacity() == 0) {
vertices.reserve(vertices.data.length*2 + 9);
}
if (indices.capacity() == 0) {
indices.reserve(indices.data.length*2 + 3);
}
if (color.capacity() == 0) {
color.reserve(color.data.length*2 + 12);
}
int firstVertex = to!int(vertices.data.length);
int firstIndice = to!int(indices.data.length);
int firstColor = to!int( color.data.length);
vertices.put( [triangleX-width/2.0, triangleY-width/2.0, triangleZ,
triangleX+width/2.0, triangleY-width/2.0, triangleZ,
triangleX, triangleY+width/2.0, triangleZ ] );
//Add the lines to connect vertices
int n = to!int(indices.data.length);
indices.put( [n, n+1, n+2] );
//For each vertex we need a color R, G, B, A
color.put( [colorR, colorG, colorB, colorA,
colorR, colorG, colorB, colorA,
colorR, colorG, colorB, colorA] );
int lastVertex = to!int(vertices.data.length);
int lastIndice = to!int(indices.data.length);
int lastColor = to!int(color.data.length);
if (updateBuffers) {
updateIndiceBufferPartial(firstIndice, lastIndice-firstIndice);
updateVertexBufferPartial(firstVertex, lastVertex-firstVertex);
updateColorBufferPartial(firstColor, lastColor-firstColor);
}
return VertexGroup(firstVertex, lastVertex, firstColor, lastColor, firstIndice, lastIndice, this);
}
VertexGroup addSquare(double squareX, double squareY, double squareZ, double size) {
if (vertices.capacity() == 0) {
vertices.reserve(vertices.data.length*2 + 12);
}
if (indices.capacity() == 0) {
indices.reserve(indices.data.length*2 + 6);
}
if (color.capacity() == 0) {
color.reserve(color.data.length*2 + 16);
}
int firstVertex = to!int(vertices.data.length);
int firstIndice = to!int(indices.data.length);
int firstColor = to!int( color.data.length);
vertices.put(
[ squareX-size/2.0, squareY-size/2.0, squareZ,
squareX-size/2.0, squareY+size/2.0, squareZ,
squareX+size/2.0, squareY-size/2.0, squareZ,
squareX+size/2.0, squareY+size/2.0, squareZ] );
//Add the lines to connect vertices
int n = to!int(indices.data.length);
indices.put( [n, n+1, n+2, n+3, n+2, n+1] );
//For each vertex we need a color R, G, B, A
color.put( [colorR, colorG, colorB, colorA,
colorR, colorG, colorB, colorA,
colorR, colorG, colorB, colorA,
colorR, colorG, colorB, colorA] );
int lastVertex = to!int(vertices.data.length);
int lastIndice = to!int(indices.data.length);
int lastColor = to!int(color.data.length);
if (updateBuffers) {
updateIndiceBufferPartial(firstIndice, lastIndice-firstIndice);
updateVertexBufferPartial(firstVertex, lastVertex-firstVertex);
updateColorBufferPartial(firstColor, lastColor-firstColor);
}
return VertexGroup(firstVertex, lastVertex, firstColor, lastColor, firstIndice, lastIndice, this);
}
void render(Camera camera) {
program.use();
//Set the camera location uniform
glUniformMatrix4fv(cameraUniformLocation, 1, GL_FALSE, camera.pvMat4.mat.ptr);
// Wireframe Checking
if (wireframe) glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
scope(exit) glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
//Draw the indices
//glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indiceBuffer);
glBindVertexArray(vaoID); // Bind our Vertex Array Object
//glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indiceBuffer);
glDrawArrays(DrawMode.Triangles, 0, to!int(indices.data.length));
//glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
//glBindVertexArray(0); // Unbind our Vertex Array Object
//glDrawElements(DrawMode.Triangles, to!int(indices.data.length), GL_UNSIGNED_INT, cast(void*)(0) );
//glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}
}
static Shader vs;
static Shader fs;
static ShaderProgram program = null;
static void initializeShader() {
vs = new Shader(ShaderType.Vertex, vertexShaderSource);
fs = new Shader(ShaderType.Fragment, fragmentShaderSource);
program = new ShaderProgram(vs, fs);
}
static immutable vertexShaderSource = q{
#version 150
in vec3 position;
in vec4 color;
uniform mat4 pvmMatrix;
out vec4 vColor;
void main() {
vColor = color;
gl_Position = pvmMatrix * vec4(position, 1.0);
}
};
static immutable fragmentShaderSource = q{
#version 150
in vec4 vColor;
out vec4 FragColor;
void main() {
FragColor = vColor;
}
};
struct VertexGroup {
int firstVertex, lastVertex;
int firstColor, lastColor;
int firstIndice, lastIndice;
UltraMesh ultraMesh;
float centerX = 0;
float centerY = 0;
float centerZ = 0;
static VertexGroup opCall(int fV, int lV, int fC, int lC, int fI, int lI, UltraMesh uM)
{
VertexGroup vg = VertexGroup.init;
vg.firstVertex = fV;
vg.lastVertex = lV;
vg.firstColor = fC;
vg.lastColor = lC;
vg.firstIndice = fI;
vg.lastIndice = lI;
vg.ultraMesh = uM;
vg.calculateCenter();
return vg;
}
void calculateCenter() {
int vCount = (lastVertex - firstVertex)/3;
for (int i = firstVertex; i < lastVertex; i+= 3) {
//writeln("X: ", ultraMesh.vertices.data[i], ", Y: ", ultraMesh.vertices.data[i+1]);
centerX += ultraMesh.vertices.data[i]/vCount;
centerY += ultraMesh.vertices.data[i+1]/vCount;
centerZ += ultraMesh.vertices.data[i+2]/vCount;
}
}
void rotateX(float angle) {
float s = sin(angle);
float c = cos(angle);
for (int i = firstVertex; i < lastVertex; i+=3) {
float z = ultraMesh.vertices.data[i+2] - centerZ;
float y = ultraMesh.vertices.data[i+1] - centerY;
ultraMesh.vertices.data[i+2] = z * c - y * s + centerZ;
ultraMesh.vertices.data[i+1] = y * c + z * s + centerY;
}
if (ultraMesh.updateBuffers) ultraMesh.updateVertexBufferPartial(firstVertex, lastVertex-firstVertex);
}
void rotateY(float angle) {
float s = sin(angle);
float c = cos(angle);
for (int i = firstVertex; i < lastVertex; i+=3) {
float x = ultraMesh.vertices.data[i] - centerX;
float z = ultraMesh.vertices.data[i+2] - centerZ;
ultraMesh.vertices.data[i] = x * c - z * s + centerX;
ultraMesh.vertices.data[i+2] = z * c + x * s + centerZ;
}
if (ultraMesh.updateBuffers) ultraMesh.updateVertexBufferPartial(firstVertex, lastVertex-firstVertex);
}
void rotateZ(float angle) {
float s = sin(angle);
float c = cos(angle);
for (int i = firstVertex; i < lastVertex; i+=3) {
float x = ultraMesh.vertices.data[i] - centerX;
float y = ultraMesh.vertices.data[i+1] - centerY;
ultraMesh.vertices.data[i] = x * c - y * s + centerX;
ultraMesh.vertices.data[i+1] = y * c + x * s + centerY;
}
if (ultraMesh.updateBuffers) ultraMesh.updateVertexBufferPartial(firstVertex, lastVertex-firstVertex);
}
void translateX(float value) {
for (int i = firstVertex; i < lastVertex; i+= 3) {
ultraMesh.vertices.data[i] += value;
}
centerX += value;
if (ultraMesh.updateBuffers) ultraMesh.updateVertexBufferPartial(firstVertex, lastVertex-firstVertex);
}
void translateY(float value) {
for (int i = firstVertex; i < lastVertex; i+= 3) {
ultraMesh.vertices.data[i+1] += value;
}
centerY += value;
if (ultraMesh.updateBuffers) ultraMesh.updateVertexBufferPartial(firstVertex, lastVertex-firstVertex);
}
void translateZ(float value) {
for (int i = firstVertex; i < lastVertex; i+= 3) {
ultraMesh.vertices.data[i+2] += value;
}
centerZ += value;
if (ultraMesh.updateBuffers) ultraMesh.updateVertexBufferPartial(firstVertex, lastVertex-firstVertex);
}
void setPosition(float xPos, float yPos, float zPos) {
float moveX = xPos-centerX;
float moveY = yPos-centerY;
float moveZ = zPos-centerZ;
centerX = xPos;
centerY = yPos;
centerZ = zPos;
for (int i = firstVertex; i < lastVertex; i+= 3) {
ultraMesh.vertices.data[i] += moveX;
ultraMesh.vertices.data[i+1] += moveY;
ultraMesh.vertices.data[i+2] += moveZ;
}
if (ultraMesh.updateBuffers) ultraMesh.updateVertexBufferPartial(firstVertex, lastVertex-firstVertex);
}
void setColor(float r, float g, float b, float a) {
ubyte rByte = to!ubyte(to!int(r*255));
ubyte gByte = to!ubyte(to!int(g*255));
ubyte bByte = to!ubyte(to!int(b*255));
ubyte aByte = to!ubyte(to!int(a*255));
for (int i = firstColor; i < lastColor; i += 4) {
ultraMesh.color.data[i] = rByte;
ultraMesh.color.data[i+1] = gByte;
ultraMesh.color.data[i+2] = bByte;
ultraMesh.color.data[i+3] = aByte;
}
if (ultraMesh.updateBuffers) ultraMesh.updateColorBufferPartial(firstColor, lastColor-firstColor);
}
}
Pastebin for better formatting:
http://pastebin.com/1B9B2KsU
I believe I'm setting the indices correctly, any idea why this happens?

Answer 1

n should be equal to vertices/3 instead of indices.