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[英]C++ SDL2 Error when trying to render SDL_Texture: Invalid texture
[英]Trying to implement Render to Texture
我在使用OpenGL 3實現渲染到紋理時遇到了麻煩。
我的問題是渲染到幀緩沖區后,看起來渲染的對象變形,這可能意味着某處發生了不良的轉換。 這沒有意義,因為當不使用我的幀緩沖區時對象渲染得很好(參見帖子的底部)。
目前的結果如下:
目前的結果http://k.minus.com/jZVgUuLYRtapv.jpg
預期的結果就是這個(或類似的,這只是GIMP): 預計http://k.minus.com/jA5rLM8lmXQYL.jpg
因此,它暗示我在幀緩沖區設置代碼或其他地方做錯了。 但我看不清楚。
FBO通過以下功能設置:
unsigned int fbo_id;
unsigned int depth_buffer;
int m_FBOWidth, m_FBOHeight;
unsigned int m_TextureID;
void initFBO() {
m_FBOWidth = screen_width;
m_FBOHeight = screen_height;
glGenRenderbuffers(1, &depth_buffer);
glBindRenderbuffer(GL_RENDERBUFFER, depth_buffer);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, m_FBOWidth, m_FBOHeight);
glGenTextures(1, &m_TextureID);
glBindTexture(GL_TEXTURE_2D, m_TextureID);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, m_FBOWidth, m_FBOHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
glBindTexture(GL_TEXTURE_2D, 0);
glGenFramebuffers(1, &fbo_id);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo_id);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depth_buffer);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_TextureID, 0);
assert(glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
}
這是我的繪圖框代碼,它只需要一個轉換矩陣並調用相應的函數。 P的當前值是投影矩陣,以及視圖矩陣(V)的單位矩陣。
void drawBox(const Matrix4& M) {
const Matrix4 MVP = M * V * P;
if (boundshader) {
glUniformMatrix4fv((*boundshader)("MVP"), 1, GL_FALSE, &MVP[0]);
}
glBindVertexArray(vaoID);
glDrawElements(GL_TRIANGLES, sizeof(cube.polygon)/sizeof(cube.polygon[0]), GL_UNSIGNED_INT, 0);
}
void drawStaticBox() {
Matrix4 M(1);
translate(M, Vector3(0,0,-50));
drawBox(M);
}
void drawRotatingBox() {
Matrix4 M(1);
rotate(M, rotation(Vector3(1, 0, 0), rotation_x));
rotate(M, rotation(Vector3(0, 1, 0), rotation_y));
rotate(M, rotation(Vector3(0, 0, 1), rotation_z));
translate(M, Vector3(0,0,-50));
drawBox(M);
}
並且GLUT調用顯示功能。
void OnRender() {
/////////////////////////////////////////
// Render to FBO
glClearColor(0, 0, 0.2f,0);
glBindFramebuffer(GL_FRAMEBUFFER, fbo_id);
glViewport(0, 0, m_FBOWidth, m_FBOHeight);
glClear(GL_COLOR_BUFFER_BIT| GL_DEPTH_BUFFER_BIT);
GL_CHECK_ERRORS
colorshader.Use();
boundshader = &colorshader;
drawRotatingBox();
colorshader.UnUse();
/////////////////////////////////////////
// Render to Window
glClearColor(0, 0, 0, 0);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glViewport(0, 0, screen_width, screen_height);
glClear(GL_COLOR_BUFFER_BIT| GL_DEPTH_BUFFER_BIT);
GL_CHECK_ERRORS
texshader.Use();
boundshader = &texshader;
glBindTexture(GL_TEXTURE_2D, m_TextureID);
drawStaticBox();
texshader.UnUse();
// Swap le buffers
glutSwapBuffers();
}
並且...強制紋理着色器代碼
頂點
#version 330
in vec2 vUV;
in vec3 vVertex;
smooth out vec2 vTexCoord;
uniform mat4 MVP;
void main()
{
vTexCoord = vUV;
gl_Position = MVP*vec4(vVertex,1);
}
分段
#version 330
smooth in vec2 vTexCoord;
out vec4 vFragColor;
uniform sampler2D textureMap;
void main(void)
{
vFragColor = texture(textureMap, vTexCoord);
}
以下是不使用FBO邏輯時 呈現的內容:向FBO呈現的內容http://k.minus.com/jiP7kTOSLLvHk.jpg
... 救命?
關於我可能做錯的任何想法? 可根據要求提供更多來源。
在不仔細查看代碼的情況下,這是一些可行的示例FBO代碼(將茶壺動畫為紋理,將紋理繪制到旋轉立方體的兩側)。
#include <GL/glew.h>
#include <GL/glut.h>
#include <cmath>
#include <iostream>
using namespace std;
namespace render
{
int width, height;
float aspect;
void init();
void reshape(int width, int height);
void display();
int const fbo_width = 512;
int const fbo_height = 512;
GLuint fb, color, depth;
};
void idle();
int main(int argc, char *argv[])
{
glutInit(&argc, argv);
glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH );
glutCreateWindow("FBO test");
glutDisplayFunc(render::display);
glutReshapeFunc(render::reshape);
glutIdleFunc(idle);
glewInit();
render::init();
glutMainLoop();
return 0;
}
void idle()
{
glutPostRedisplay();
}
void CHECK_FRAMEBUFFER_STATUS()
{
GLenum status;
status = glCheckFramebufferStatus(GL_DRAW_FRAMEBUFFER);
switch(status) {
case GL_FRAMEBUFFER_COMPLETE:
break;
case GL_FRAMEBUFFER_UNSUPPORTED:
/* choose different formats */
break;
default:
/* programming error; will fail on all hardware */
throw "Framebuffer Error";
}
}
namespace render
{
float const light_dir[]={1,1,1,0};
float const light_color[]={1,0.95,0.9,1};
void init()
{
glGenFramebuffers(1, &fb);
glGenTextures(1, &color);
glGenRenderbuffers(1, &depth);
glBindFramebuffer(GL_FRAMEBUFFER, fb);
glBindTexture(GL_TEXTURE_2D, color);
glTexImage2D( GL_TEXTURE_2D,
0,
GL_RGBA,
fbo_width, fbo_height,
0,
GL_RGBA,
GL_UNSIGNED_BYTE,
NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, color, 0);
glBindRenderbuffer(GL_RENDERBUFFER, depth);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, fbo_width, fbo_height);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depth);
CHECK_FRAMEBUFFER_STATUS();
}
void reshape(int width, int height)
{
render::width=width;
render::height=height;
aspect=float(width)/float(height);
glutPostRedisplay();
}
void prepare()
{
static float a=0, b=0, c=0;
glBindTexture(GL_TEXTURE_2D, 0);
glEnable(GL_TEXTURE_2D);
glBindFramebuffer(GL_FRAMEBUFFER, fb);
glViewport(0,0,fbo_width, fbo_height);
glClearColor(1,1,1,0);
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45, 1, 1, 10);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glEnable(GL_LIGHT0);
glEnable(GL_LIGHTING);
glEnable(GL_DEPTH_TEST);
glDisable(GL_CULL_FACE);
glLightfv(GL_LIGHT0, GL_POSITION, light_dir);
glLightfv(GL_LIGHT0, GL_DIFFUSE, light_color);
glTranslatef(0,0,-5);
glRotatef(a, 1, 0, 0);
glRotatef(b, 0, 1, 0);
glRotatef(c, 0, 0, 1);
glutSolidTeapot(0.75);
a=fmod(a+0.1, 360.);
b=fmod(b+0.5, 360.);
c=fmod(c+0.25, 360.);
}
void final()
{
static float a=0, b=0, c=0;
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glViewport(0,0, width, height);
glClearColor(1.,1.,1.,0.);
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45, aspect, 1, 10);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0,0,-5);
glRotatef(b, 0, 1, 0);
b=fmod(b+0.5, 360.);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, color);
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glDisable(GL_LIGHTING);
float cube[][5]=
{
{-1, -1, -1, 0, 0},
{ 1, -1, -1, 1, 0},
{ 1, 1, -1, 1, 1},
{-1, 1, -1, 0, 1},
{-1, -1, 1, -1, 0},
{ 1, -1, 1, 0, 0},
{ 1, 1, 1, 0, 1},
{-1, 1, 1, -1, 1},
};
unsigned int faces[]=
{
0, 1, 2, 3,
1, 5, 6, 2,
5, 4, 7, 6,
4, 0, 3, 7,
3, 2, 6, 7,
4, 5, 1, 0
};
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glVertexPointer(3, GL_FLOAT, 5*sizeof(float), &cube[0][0]);
glTexCoordPointer(2, GL_FLOAT, 5*sizeof(float), &cube[0][3]);
glCullFace(GL_BACK);
glDrawElements(GL_QUADS, 24, GL_UNSIGNED_INT, faces);
glCullFace(GL_FRONT);
glDrawElements(GL_QUADS, 24, GL_UNSIGNED_INT, faces);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
}
void display()
{
prepare();
final();
glutSwapBuffers();
}
}
只是為了參考有一些有用的東西。
不確定為什么要在着色器中乘以矩陣。 假設您想要在屏幕上拉伸渲染到紋理紋理,您只需要定義4個頂點,在x和y上從-1到1,並將這些頂點傳遞到着色器(如果您正在繪制,則為4個頂點)當然是一個帶有2個三角形的條帶)。
在着色器中,只需將頂點乘以0.5並添加0.5即可獲得紋理坐標。 因此,您不需要傳遞紋理坐標,因為您可以直接在頂點着色器中生成這些坐標。 如果將頂點定義為-1到1,則頂點已經在屏幕空間中,因此除了從頂點着色器發出頂點之外,您不需要對它們執行任何操作。
正如Jari Komppa在GameDev.stackexchange上指出的那樣,以及neodelphi作為對我主帖的評論。
紋理坐標是錯誤的(或者在我的情況下,沒有傳遞)。
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