How to draw VertexArray ?

[Takoo]

Hello,
My goal is to draw a tylemap from int*.
After 2 hours of research i didn't resolve my problem :

[Takoo@localhost my_runner_2017]$ make re
rm -f ./src/main.o
rm -f my_runner
gcc -g3 -Wextra -Wall -Werror -I./include   -c -o src/main.o src/main.c
src/main.c: In function ‘main’:
src/main.c:60:50: error: incompatible type for argument 3 of ‘sfRenderWindow_drawVertexArray’
   sfRenderWindow_drawVertexArray(window, vertex, states);
                                                  ^~~~~~
In file included from /usr/local/include/SFML/Graphics.h:46:0,
                 from src/../include/my.h:11,
                 from src/main.c:8:
/usr/local/include/SFML/Graphics/RenderWindow.h:432:25: note: expected ‘const sfRenderStates * {aka const struct <anonymous> *}’ but argument is of type ‘sfRenderStates {aka struct <anonymous>}’
 CSFML_GRAPHICS_API void sfRenderWindow_drawVertexArray(sfRenderWindow* renderWindow, const sfVertexArray* object, const sfRenderStates* states);
                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
make: *** [<builtin>: src/main.o] Error 1
[Takoo@localhost my_runner_2017]$
 

I don't understand why my sfRenderWindow_drawVertexArray (L.60) wait a * sfRenderStates while every examples on web uses sfRenderStates without "*".

Here is my code :

(click to show/hide)

#include "../include/my.h"

int main()
{
        int width = 5;
        int height = 3;
        sfVideoMode mode = {512, 256, 32};
        sfRenderWindow *window = sfRenderWindow_create(mode, "MY_RUNNER", sfResize | sfClose, NULL);
        int lvl[] =
        {
                2, 2, 2, 2, 2,
                2, 2, 1, 2, 1,
                0, 0, 0, 0, 0,
        };
        sfTexture *texture = sfTexture_createFromFile("./img/social.png", NULL);
        sfVertexArray *vertex = sfVertexArray_create();
        sfVertexArray_setPrimitiveType(vertex, sfQuads);
        sfVertexArray_resize(vertex, width * height * 4);
        for (int i = 0; i < width; i++) {
                for (int j = 0; j < height; j++) {
                        int nbr = lvl[i + j * width];
                        sfVertex *quad = sfVertexArray_getVertex(vertex, (i + j * width) * 4);
                        quad[0].position = (sfVector2f){i * 32, j * 32};
                        quad[1].position = (sfVector2f){(i + 1) * 32, j * 32};
                        quad[2].position = (sfVector2f){(i + 1) * 32, (j + 1) * 32};
                        quad[3].position = (sfVector2f){i * 32, (j + 1) * 32};
                       
                        quad[0].texCoords = (sfVector2f){nbr * 32, 0};
                        quad[1].texCoords = (sfVector2f){(nbr + 1) * 32, 0};
                        quad[2].texCoords = (sfVector2f){(nbr + 1) * 32, 32};
                        quad[3].texCoords = (sfVector2f){nbr * 32, 32};
                }
        }
        sfRenderStates states;
        states.texture = texture;
       
       
       
        while (sfRenderWindow_isOpen(window))
        {
                sfEvent event;
                while (sfRenderWindow_pollEvent(window, &event))
                {
                        if (event.type == sfEvtClosed)
                                sfRenderWindow_close(window);
                }
                sfRenderWindow_clear(window, sfBlack);
                sfRenderWindow_drawVertexArray(window, vertex, states);
                sfRenderWindow_display(window);
        }
        sfTexture_destroy(texture);
        sfVertexArray_destroy(vertex);
        sfRenderWindow_destroy(window);
        return (0);
}
 

Thank's for ur help ! 

[FRex]

Most examples online are in C++ and not C. The error is clear, you need to pass a pointer to render states to that function.

[Takoo]

Most examples online are in C++ and not C. The error is clear, you need to pass a pointer to render states to that function.

Hi, thanks for ur reply.
I found the problem but now my program segfault when I set texture to my RenderState (L.42: states->texture = texture;).
Error :

(click to show/hide)

[Takoo@localhost my_runner_2017]$ valgrind ./my_runner
[Takoo@localhost my_runner_2017]$ valgrind ./my_runner
==4788== Memcheck, a memory error detector
==4788== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==4788== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==4788== Command: ./my_runner
==4788==
==4788== Invalid write of size 8
==4788==    at 0x400DAF: main (main.c:42)
==4788==  Address 0x40 is not stack'd, malloc'd or (recently) free'd
==4788==
==4788==
==4788== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==4788==  Access not within mapped region at address 0x40
==4788==    at 0x400DAF: main (main.c:42)
==4788==  If you believe this happened as a result of a stack
==4788==  overflow in your program's main thread (unlikely but
==4788==  possible), you can try to increase the size of the
==4788==  main thread stack using the --main-stacksize= flag.
==4788==  The main thread stack size used in this run was 8388608.
==4788==
==4788== HEAP SUMMARY:
==4788==     in use at exit: 69,045,346 bytes in 7,012 blocks
==4788==   total heap usage: 22,750 allocs, 15,738 frees, 129,593,621 bytes allocated
==4788==
==4788== LEAK SUMMARY:
==4788==    definitely lost: 96 bytes in 2 blocks
==4788==    indirectly lost: 0 bytes in 0 blocks
==4788==      possibly lost: 68,644,326 bytes in 5,675 blocks
==4788==    still reachable: 400,924 bytes in 1,335 blocks
==4788==         suppressed: 0 bytes in 0 blocks
==4788== Rerun with --leak-check=full to see details of leaked memory
==4788==
==4788== For counts of detected and suppressed errors, rerun with: -v
==4788== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
Segmentation fault (core dumped)
 

My code :

(click to show/hide)

#include "../include/my.h"

int main()
{
        int width = 5;
        int height = 3;
        sfVideoMode mode = {160, 96, 32};
        sfRenderWindow *window = sfRenderWindow_create(mode, "MY_RUNNER", sfResize | sfClose, NULL);
        int lvl[] =
        {
                2, 2, 2, 2, 2,
                2, 2, 1, 2, 1,
                0, 0, 0, 0, 0,
        };
        sfTexture *texture = sfTexture_createFromFile("img/bg0.jpg", NULL);
        sfVertexArray *vertex = sfVertexArray_create();
        sfVertexArray_setPrimitiveType(vertex, sfQuads);
        sfVertexArray_resize(vertex, width * height * 4);
        for (int i = 0; i < width; i++) {
                for (int j = 0; j < height; j++) {
                        int nbr = lvl[i + j * width];
                        sfVertex *quad = sfVertexArray_getVertex(vertex, (i + j * width) * 4);
                        quad[0].position = (sfVector2f){i * 32, j * 32};
                        quad[1].position = (sfVector2f){(i + 1) * 32, j * 32};
                        quad[2].position = (sfVector2f){(i + 1) * 32, (j + 1) * 32};
                        quad[3].position = (sfVector2f){i * 32, (j + 1) * 32};
                       
                        quad[0].texCoords = (sfVector2f){nbr * 32, 0};
                        quad[1].texCoords = (sfVector2f){(nbr + 1) * 32, 0};
                        quad[2].texCoords = (sfVector2f){(nbr + 1) * 32, 32};
                        quad[3].texCoords = (sfVector2f){nbr * 32, 32};
                }
        }
        sfRenderStates *states = NULL;
        states->texture = texture;  << SEGFAULT HERE <<
       
       
        while (sfRenderWindow_isOpen(window))
        {
                sfEvent event;
                while (sfRenderWindow_pollEvent(window, &event))
                {
                        if (event.type == sfEvtClosed)
                                sfRenderWindow_close(window);
                }
                sfRenderWindow_clear(window, sfBlack);
                sfRenderWindow_drawVertexArray(window, vertex, states);
                sfRenderWindow_display(window);
        }
        sfTexture_destroy(texture);
        sfVertexArray_destroy(vertex);
        sfRenderWindow_destroy(window);
        return (0);
}
 

[Laurent]

states is NULL, you can't access its texture member. You need a valid sfRenderStates instance.